GARY PADGETT'S MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY SEPTEMBER, 2002 (For general comments about the nature of these summaries, as well as information on how to download the tabular cyclone track files, see the Author's Note at the end of this summary.) ************************************************************************* SEPTEMBER HIGHLIGHTS --> Record number of September tropical storms form in Atlantic --> Two Caribbean hurricanes strike western Cuba and U. S. Gulf Coast --> Devastating hurricane strikes Mexico's Yucatan Peninsula --> Years 7th super typhoon forms in Northwest Pacific--strikes Japan --> Southwest Indian Ocean tropical depression damaging to Seychelles --> "Subtropical wanderer" becomes the Atlantic's third longest-lived tropical cyclone on record ************************************************************************* ***** Feature of the Month for September ***** SOUTHERN HEMISPHERE TROPICAL CYCLONE NAMES 2002 - 2003 SEASON TROPICAL CYCLONE NAMES for the AUSTRALIAN REGION The Australian Bureau of Meteorology maintains three Tropical Cyclone Warning Centres (TCWC): Perth, Western Australia; Darwin, Northern Territory; and Brisbane, Queensland. Each centre is allotted a separate list of tropical cyclone names for tropical cyclones forming within its area of responsibility (AOR). In addition a TCWC located at Port Moresby, Papua New Guinea (PNG)--a former Australian territory-- maintains a list of native names to assign to the very rare tropical cyclones which form within its AOR. The AORs of the respective centres are: (1) Perth - 125E westward to 90E and south of 10S. Currently, and for at least the next few years, the Perth TCWC will issue warnings for any systems north of 10S and south and west of the Indonesian islands. (2) Darwin - 125E eastward to 138E and extending northward to the equator. There is a little irregularity with the eastern border in the Gulf of Carpentaria. The Darwin TCWC issues High Seas Warnings for the entire Gulf of Carpentaria, but Brisbane issues Tropical Cyclone Advices and names cyclones in the eastern portion of the Gulf. Also, currently, and for at least the next few years, the Darwin TCWC will issue warnings for any systems west of 125E and within the Indonesian archipelago in the Banda, Flores, and Java Seas. (3) Brisbane - 138E eastward to 160E and generally south of 10S. The northern border with the Port Moresby AOR is somewhat irregular. (4) Port Moresby, PNG - immediate vicinity of the island of New Guinea and eastward to 160E generally north of 10S although the southern border is somewhat irregular. Names for the 2002-2003 season (** indicates name has already been assigned): Perth Darwin Brisbane Port Moresby ----------------------------------------------------------------------- Fiona Craig Erica Epi Graham Debbie Fritz Guba Harriet Evan Grace Ila Inigo Fay Harvey Kama Jana George Ingrid Matere Ken Helen Jim Rowe Linda Ira Kate Tako Monty Jasmine Larry Upia (See Note) Nicky Kim Monica Oscar Laura Nelson Phoebe Odette Raymond Pierre Sally Rebecca Tim Sandy Vivienne Tania NOTE: I must admit I really don't know what to expect with regard to naming of tropical cyclones by the Port Moresby TCWC. The list given above is the one which has been advertized for years, and is still included in the WMO Region V Operational Plan. However, in May, 2002, the first tropical cyclone in Port Moresby's AOR in nine years formed and was named Upia--the last name on the list. Ostensibly, that name will not be used again, but I really don't know what the next storm to develop in that region will be named. We'll just have to wait and see. TROPICAL CYCLONE NAMES for the SOUTHWEST INDIAN OCEAN and the SOUTH PACIFIC OCEAN The Tropical Cyclone Warning Centre (TCWC) at Nadi, Fiji, has tropical cyclone warning responsibility for the South Pacific east of 160E and from the equator to 25S. The Meteorological Service of New Zealand at Wellington has warning responsibility for waters south of 25S, but almost all tropical cyclones in this basin form north of 25S. When a rare cyclone forms in the Wellington area of responsibility (AOR), it usually will be assigned a name from the Fiji list (such as was done for Tropical Cyclone Gita in February, 1999.) Tropical cyclone warning responsibility for South Indian waters west of 90E are shared by several TCWCs. The Regional Specialty Meteorological Centre (RSMC) for the region is the office of Meteo France on the island of La Reunion. However, following a long-standing practice, the sub-regional centres at Mauritius and Madagascar share the responsibility for actually naming tropical storms with Mauritius naming systems east of 55E and Madagascar covering the area west of 55E. RSMC La Reunion issues warnings for the basin independently of these sub-regional centres, but only advises regarding when or when not to assign a name to a developing cyclone. Names for the 2002-2003 season (** indicates name has already been assigned): Southwest Indian South Pacific ----------------------------------------------------------------------- Atang ** Noe Yolande ** Ivy Boura ** Opanga Zoe Judy Crystal Pale Ami Kerry Delfina Qacha Beni Lola Ebula Rita Cilla Meena Fari Serame Dovi Nancy Gerry Tina Eseta Olaf Hape Ulysse Fili Percy Isha Vicente Gina Rae Japhet Winston Heta Sheila Kalunde Xena Luma Yves Manou Zaitoune *********************************************************************** ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for September: 1 tropical depression 4 tropical storms 4 hurricanes 1 hybrid system Sources of Information ---------------------- Most of the information presented below was obtained from the various tropical cyclone products issued by the Tropical Prediction Center/National Hurricane Center (TPC/NHC) in Miami, Florida: discussions, public advisories, forecast/advisories, tropical weather outlooks, special tropical disturbance statements, etc. Some additional information may have been gleaned from the monthly summaries prepared by the hurricane specialists and available on TPC/NHC's website. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. I'd like to extend a very special thanks to Kevin Boyle and John Wallace for their assistance in writing storm reports. Kevin wrote the summaries for Edouard, TD-07, Josephine and Kyle, and a big chunk of the reports on Hanna, Isidore and Lili. John, in addition to his Eastern Pacific duties, authored the summary on Tropical Storm Fay. A big thanks is due also to Chris Fogarty for his report on Hurricane Gustav, and to Chris and Jack Beven for the information and comments they provided regarding the Newfoundland hybrid system of 5 September. Atlantic Tropical Activity for September ---------------------------------------- A new record was set in the Atlantic basin during September, 2002. For the first time on record, eight tropical storms formed during a calendar month. Seven have occurred on several occasions: August, 1933; September, 1949; September, 1988; August, 1995; and September, 2000. There have also been a few occasions when nine storms developed during a 30-day period or less, but never with eight systems reaching tropical storm intensity within one calendar month. Of the eight tropical cyclones, four reached hurricane intensity and two became intense hurricanes. Over the period 1950-2001, the September averages for "named" storms, hurricanes, and intense hurricanes are 3.40, 2.40, and 1.25, respectively. In addition to the eight tropical storms and hurricanes, another tropical depression formed but was quite short- lived and did not reach tropical storm intensity. As the month of September opened Tropical Storm Dolly was located far to the east of the Lesser Antilles, struggling against hostile upper-level shear. The storm subsequently turned northward and had dissipated by the 4th far to the southeast of Bermuda. The pattern of short-lived cyclones of higher-latitude origin seen during July and August continued well into September. Of the eight named cyclones forming in September, six were of non-tropical origin. Only Hurricanes Isidore and Lili, plus the non-developing depression, formed in the tropics from African waves. Tropical Storm Edouard formed during the first week of the month off the northeastern Florida coast, made a loop, then moved west-southwestward, making landfall as a very minimal tropical storm near Flagler Beach. The weakening depression continued across the northern peninsula and moved into the northeastern Gulf of Mexico where it dissipated. At about the same time that Edouard was dissipating, a disturbance off the Texas coast intensified into Tropical Storm Fay. After remaining quasi-stationary for a day or so, Fay moved westward into the mid-Texas coast and soon weakened to a tropical depression. The remnant depression meandered over southern Texas and northern Mexico for several days, dropping hefty amounts of rainfall which led to substantial flooding. As Fay's remnants were weakening over Texas and Mexico, a subtropical LOW began developing southeast of North Carolina and became Subtropical Storm Gustav--the first subtropical storm to be named under TPC/NHC's new operational policy which was adopted in late 2001. After a couple of days Gustav had acquired predominant tropical characteristics and was reclassified as a tropical cyclone. The storm recurved just east of Cape Hatteras, then accelerated rapidly to the northeast. Gustav reached hurricane intensity on 11 September as it was speeding northeastward--the latest date for the first hurricane of the year since 1941. Gustav began transforming into an extratropical cyclone as it neared eastern Nova Scotia, but made landfall as a nominal hurricane. Around mid-month weak Tropical Storm Hanna formed in the north-central Gulf of Mexico and made landfall along the northern Gulf of Mexico coastline. Hurricane Isidore formed in the Northwest Caribbean shortly after the middle of September and became the first of the year's two major hurri- canes on the Saffir/Simpson Scale. Isidore crossed western Cuba as a Category 1 hurricane, then deepened into a major Category 3 hurricane as it progressed westward across the southern Gulf of Mexico. On the 22nd the storm made an unexpected hard left turn and moved inland into Mexico's Yucatan Peninsula near Merida. The storm meandered about over land for a couple of days, weakening into a tropical storm. After moving back out into the Gulf, Isidore began a northward trek which eventually carried it into the Louisiana coastline just west of New Orleans as a strong tropical storm. At about the time that Isidore was developing in the Caribbean, Tropical Storm Josephine formed well to the east of Bermuda. Josephine soon began moving northeastward and within 36 hours had merged with a cold front and lost tropical character- istics. A few days after Josephine's formation, a subtropical LOW began taking shape in the same general area. This system was dubbed Subtropical Storm Kyle on the 21st and was reclassified as a tropical storm the next day. Kyle was destined to wander aimlessly around the Western Atlantic sub- tropics for the next three weeks until it had become the Atlantic basin's third longest-lived tropical cyclone on record, after Hurricane Inga of 1969 and Hurricane Ginger of 1971, both of which were also "subtropical wanderers". Kyle did crank up into a 75-kt hurricane at one point while located east-southeast of Bermuda. Subsequently, the cyclone went through cycles of weakening and re-intensifying--counting its initial classification as a tropical storm, Kyle was upgraded to tropical storm intensity five times. The storm eventually moved westward, then turned northward, grazing the North Carolina coastline before heading out to sea and becoming extratropical. As an extratropical cyclone, Kyle remained on the charts for several days, and at one point looked as if it had ideas of taking on tropical characteristics again. Finally, on 18 October the remnants of Kyle were absorbed into a strong extratropical cyclone southwest of the British Isles. The month's final cyclone was Hurricane Lili, which turned out to be the year's most intense hurricane. Lili's track was remarkably similar to that of Isidore. Lili, however, reached tropical storm intensity east of the Windward Islands before entering the Caribbean Sea. After nearing hurricane intensity, the storm weakened briefly into a strong tropical wave south of Hispaniola. However, Lili soon recovered, and after flirting with Jamaica for a couple of days, began a steady west- northwestward track toward the western tip of Cuba, which had been visited by Isidore only a week earlier. The storm crossed western Cuba as a Category 2 hurricane on 1 October and entered the Gulf of Mexico on a northwestward heading. On the 2nd Lili intensified dramatically into a severe Category 4 hurricane as it took aim on the central Louisiana coast; then, just as suddenly, weakened in the final hours before landfall so that it came ashore as a minimal Category 2 hurricane. Newfoundland Storm System of 5 September ---------------------------------------- One additional system needs commenting on--I received an e-mail from Chris Fogarty on the evening of 5 September regarding a system which earlier that day had crossed Newfoundland. Chris' comments follow (slightly edited): "Another one of those 'curious critters' formed over the Northwest Atlantic early on 5 September. The storm started out as a mass of convection well south of the Grand Banks of Newfoundland. The storm moved across the Avalon Peninsula of Newfoundland, producing heavy rain and gusty winds. A hook-and-eye type feature formed on radar. Satellite imagery showed a round cloud shield. It seems to me this was a case of rapid cyclogenesis aided by low static stability and convection over the cyclone center." In a later message Chris stated that the system was similar to the storm on 7 July (see July summary) which passed near Sable Island--a hybrid system embedded on a front. Chris had originally sent the e-mail, along with some satellite and radar images as well as sounding data, to Jack Beven also. After I had sent out Part 2 of the September summary, Jack replied that he had finally had time to take a closer look at the system. His comments follow: "1. Our surface analysis (NHC's) had this LOW at the western end of a front for most of its life. That might disqualify it from being a subtropical cyclone, but looking at the details of the analysis and at satellite imagery, the strength of the "front" is somewhat dubious. It seems to me that much of the apparent temperature gradient is due to the sea surface temperatures and not to true air mass contrast. "2. The system moved northward in the warm sector of a baroclinic system to the west. That is a good sign, suggesting that there was little or no cold air intrusion into the system until it was north of Newfoundland. "3. The radar hook is quite interesting. However, it doesn't fit very well with the visible satellite image from 10 minutes earlier, which suggests an exposed low-level center southwest of the radar hook. "4. The biggest problem I see in calling this a subtropical storm is that I can't find evidence of 35-kt sustained winds. I've checked our surface analyses, I've (partly) checked our ship report files, I've checked QuikScat, and I can't find clear proof that the cyclone was of subtropical storm intensity. I've also looked for formal satellite intensity estimates, and there are none." And now, Chris has looked further and unearthed some more observations on the LOW. An automatic weather station at Cape Race did record sustained winds of 35 kts, with a MSLP of 1001.1 mb, at 1500 UTC on 5 September. This suggests that the system at least briefly was of gale strength. Whether it was tropical or subtropical, given the high latitude and cool temperatures, is something which will require more study. This system will not be added to the 2002 roster of tropical and subtropical cyclones at this time, but will be given further analysis later and could possibly eventually be added to the Atlantic Best Track database during the on-going reanalysis. (A special thanks to Chris and Jack for the information and comments on this interesting little system.) TROPICAL STORM EDOUARD (TC-05) 1 - 8 September ------------------------------------------ A. Storm Origins ---------------- Tropical Storm Edouard originated from an area of cloudiness and thunderstorms initially located about 475 nm east of the southern Bahamas. This disturbance was noted on a STWO issued by NHC on 29 August at 2130 UTC. The system drifted westward during the following two days with little change. However, a reconnaissance plane sent to investigate the disturbance on the afternoon of the 31st found a broad area of low pressure centred approximately 130 nm northeast of the northern Bahamas with a few squalls of 20 to 25 kts. Conditions were favourable for slow development, and on 1 September, 2100 UTC, Air Force Reserves reconnaissance, satellite imagery, radar and surface obser- vations indicated that the disturbance east of the Florida East Coast had developed into the fifth tropical depression of the season. The centre of Tropical Depression Five was located near 29.0N, 79.2W, or about 100 nm east of Daytona Beach, Florida. Reconnaissance at 01/1700 UTC found 850-mb flight-level winds of 35 kts, a broad LLCC, and a surface pressure of 1014 mb. Also, Melbourne Doppler radar had occasionally been indicating 36-40 kt winds between 3000 and 4000 metres. Satellite images showed that the main area of deep convection was east and southeast of the centre, a result of westerly shear over the area. The shear was light enough for some strengthening, and at 02/0600 UTC, after a Hurricane Hunter aircraft had reported 450 m flight- level winds of 47 kts east of the LLCC and a central pressure of 1007 mb, Tropical Depression Five was upgraded to a tropical storm in an inter- mediate advisory. Tropical Storm Edouard was located about 85 nm east of St. Augustine, Florida, and was moving slowly toward the east, perhaps in response to a mid-level shortwave trough passing to the north and also due to the LLCC following the deep convective bursts. B. Track and Intensity History ------------------------------ Edouard stalled early on 3 September near 30.3N, 70.6W. A dropsonde released at the 850-mb center found a central pressure of 1003 mb and southerly 30-kt winds at the surface, indicating that the mid-level circulation was displaced east of the LLCC. Despite the continued presence of westerly shear, Edouard maintained vigorous deep convection in the eastern quadrant. The MSW was raised to 55 kts at 03/1500 UTC after a reconnaissance aircraft reported a visual estimate of surface winds of 55-60 kts from 300 m and found flight-level winds of up to 71 kts. Edouard was at the time nearly stationary about 165 nm east of Jacksonville, Florida. This represents Edouard's peak intensity with weakening beginning soon afterward as the system began to suck in dry air and to suffer the affects of 50-kt west to west-northwesterly vertical shear. Edouard began to slowly drift west-southwestward, but became stationary again at 04/0300 UTC roughly 100 nm east-northeast of Daytona Beach. There was patchy, deep convection to the east of the LLCC at this time, and Edouard was depicted as a well-defined swirl of clouds with intermittent deep convection for the rest of its career. A low-level ridge to the north of Edouard began to guide the 35-kt tropical storm westward toward the Florida East Coast. Edouard made landfall just north of Daytona Beach between 0000 and 0100 UTC on 5 September. Surface observations indicated that the system had weakened to a depression by this time and the MSW was dropped to 25 kts at 05/0900 UTC. Six hours later, Edouard had crossed the Florida Peninsula and moved into the warm waters of the Gulf of Mexico. However, shear was too high for the system to regenerate, and furthermore, Edouard began to interact with the pre-Fay disturbance, a second negative factor. The final advisory on Edouard was issued by NHC at 06/1500 UTC, placing the dissipating centre off the Northwest Florida coast south of Ft. Walton Beach. The remnants were eventually absorbed into Tropical Storm Fay located off the Texas coast. C. Damage and Casualties ------------------------ Aside from localised flooding caused by heavy rains in Florida, there were no casualties or damage associated with Tropical Storm Edouard. (Report written by Kevin Boyle) TROPICAL STORM FAY (TC-06) 4 - 11 September -------------------------------------- A. Storm Origins ---------------- The disturbance that became Fay was noted in the eastern Gulf of Mexico as early as 31 August. However, it did not organize until 4 September, when it began to consolidate southeast of the Texas coastal bend. Though it was still ragged, the first advisory on Tropical Depression Six was issued at 2100 UTC on 5 September when it was located roughly 85 nm southeast of Houston. The classification as a depression was based on reconnaissance and offshore oil rig data. Caught in a persistent col, the depression was stationary. In fact, the tropical cyclone was eventually listed as stationary in six of the eight forecast/ advisories that the NHC issued on it. A tropical storm warning was issued for the Texas and Louisiana coasts. B. Track and Intensity History ------------------------------ The depression was upgraded to Tropical Storm Fay at 0300 UTC on 6 September after a reconnaissance plane found a 52-kt FLW--it was then located about 110 nm southeast of Galveston. The Hurricane Hunters found no well-defined LLCC; Fay was upgraded largely as a cautionary measure. Though conditions were favorable for strengthening, Fay's large circulation remained vague as it drifted ever so slowly westward south of a weak ridge. One of the forecasters on duty noted similarities between Fay and Tropical Storm Frances of 1998, a storm that was similarly large and disorganized. The amorphous storm intensified even while atmospheric conditions became less favorable, reaching 50 kts at 1500 UTC on the 6th. Amazingly, though reconnaissance aircraft measured winds as high as 68 kts and estimated a surface wind of 55 kts, they still found no closed center, making the cyclone's motion difficult to determine. The NHC stated that satellite imagery indicated only a series of smaller vortices rotating inside a larger gyre. Even so, a hurricane watch was hoisted for the Texas coast, and as Fay's upper-level situation temporarily improved, fears of a hurricane landfall increased accordingly. At 0000 UTC on the 7th Fay's CP bottomed out at 998 mb, with the MSW estimated at 50 kts, while located 90 nm south of Galveston. This was the peak intensity of Fay, which at this time looked more subtropical than tropical, an assertion corroborated by water vapor imagery taken near 1200 UTC on that day. Fay did not as much make landfall as it did reform a new center that accelerated slightly and tracked west-northwest across the center of Matagorda Bay, near Palacios, Texas, around 1030 UTC on the 7th. The MSW was roughly 50 kts with a CP of 999 mb. The Palacios weather station recorded a MSLP of 999 mb from roughly 0600 UTC to 0900 UTC while the highest recorded MSW was only 32 kts at 0554 UTC. Well away from the center, Galveston experienced a peak MSW of 31 kts from 0652-0752 UTC and a minimum SLP of 1004 mb at 0552 UTC. Port Lavaca, just across Matagorda Bay from Palacios, recorded a peak MSW of only 18 kts at 0551 UTC, and a MSLP of 1001 mb from 0936 UTC to 1001 UTC. Jamaica Beach recorded the only known storm surge measurement of 1.6 meters above the Mean Lower Low Water level. Fay quickly weakened to a depression after landfall, and turned more to the west as a ridge built to its north and west. After 1500 UTC that day, advisories were issued by the Hydrometeorological Prediction Center. The ridge north of Fay pushed it to the southwest early on the 7th, but on the 8th it turned back to the west. Fay's vortex became quasi- stationary southwest of San Antonio on the 8th, then began a slow, seemingly drunken wobble toward the U.S.-Mexico border. The depression's center crossed the Rio Grande early on the 10th and continued on a rough south-southwesterly track. Fay turned south-southeast later that day, executed a small cyclonic loop, then turned westward upon the issuance of the last advisory at 0300 UTC on 11 September. The weak center was then located only about 15 nm south of Monterrey, Mexico. By later that day, there was no trace of an organized circulation. C. Rainfall Reports ------------------- The most noteworthy aspect of Fay by far was the rain it brought to central Texas, a region that had been hit hard by catastrophic floods only two months earlier. Fay was not the disaster it was feared to be, but the rainfall amounts were robust, to say the least. Totals were high across a large swath of central Texas. The top five-day totals given in the final advisory from the Hydrometeorological Prediction Center are listed below (all figures are in centimeters and all locations are in Texas): Location Amount (cm) -------------------------------------------------------------------- Freeport/Dow Chemical 34.44 Jamaica Beach 32.66 Freeport 35.59 (as of 8 September) Pearsall 9 East 30.48 Mount Royal, San Antonio 29.97 Elk Runner, San Antonio 28.17 Kelly AFB, San Antonio 27.58 Zanzamora, San Antonio 25.78 Dilley 25.73 Hondo 21.84 Floresville 19.13 Galveston 18.87 Granger 17.34 The 90-hour storm total for San Antonio International Airport through 0900 UTC on the 10th was only 12.73 cm; this is clearly unrepresentative of the rains most of South Texas experienced, let alone Bexar County (the county San Antonio is in). According to the Click2Houston.com website, the town of Sweeny, Texas, in Brazoria County received 50.8 cm of rain. Sweeny is about 100 km south of Houston. Radar estimates from the National Climatic Data Center suggest isolated rainfall totals as high as 46 cm between Corpus Christi and Houston. D. Damage and Casualties ------------------------ Damage in Houston proper was apparently light, aside from a power outage affecting 27,000 people. Galveston escaped with only a few downed limbs and signs. In Surfside Beach, near Freeport in Brazoria County, Fay uprooted trees, mangled roofs, and damaged several homes and businesses in addition to causing flooding damage. Flood damage from Fay was substantial, and nine counties were declared federal disaster areas on 26 September. That being said, the heavy rains were most welcome in the parched Rio Grande Valley, a region that has suffered a drought for many years. Fay spawned at least three tornadoes according to the Austin American Statesman on 8 September--one in Wharton County destroyed a mobile home and severely damaged three others while one in Hungerford damaged a mobile home and a dumpster truck. Unfortunately, no specific monetary damage figures are available. No casualties are known at present. E. References ------------- *FEMA Information *90-Hour Rainfall Totals: *Five-Day Rainfall Totals: *Austin American Statesman *HPC Tropical Archive *September Monthly Summary (NHC) *Click2Houston *Rainfall Impact Info *Radar Image *Galveston Info (brief) *Jamaica Beach Storm Info (Report written by John Wallace) TROPICAL DEPRESSION (TC-07) 7 - 8 September --------------------------------------- A small area of low pressure left the western coast of Africa in early September and moved west-northwestward over the open Atlantic for several days. Tropical Weather Outlooks from NHC began mentioning the system around midday on 5 September when it was located about 1200 nm east-northeast of the Leeward Islands. By early morning of the 7th the small but well-defined system was located approximately 1100 nm east- southeast of Bermuda. The first advisory on Tropical Depression Seven was issued at 1500 UTC, 7 September, when the system had developed enough convection near the centre to be classified as a tropical depression. However, convective activity subsequently decreased and was sheared to the east of the LLCC. TD-07 was a weak system, and after the initial three advisories was devoid of convection for the rest of its short life. The tropical cyclone moved westward under a very weak mid- level ridge with a peak MSW of 30 kts. The final advisory on TD-07 was issued by NHC at 1500 UTC on 8 September after new convection failed to develop and with the system forecast to turn northwards into a region of strong vertical wind shear. (Report written by Kevin Boyle) HURRICANE GUSTAV (TC-08) 7 - 14 September ------------------------------------ A. Storm Origins ---------------- A Tropical Weather Outlook (TWO) issued by TPC/NHC on the morning of 6 September noted that an area of cloudiness and showers with a few embedded thunderstorms had developed and extended from the central Bahamas eastward and northeastward for several hundred miles. The area of disturbed weather was associated with a large upper-level LOW and a surface trough. The TWO noted that any tropical or subtropical development would likely be slow to occur. The system appeared slightly better organized on the 7th and the TWOs from NHC began to emphasize the potential for tropical or subtropical cyclone development. At 1800 UTC a weak LOW center was located approximately 425 nm east of Miami. (This from the Navy JMV file sent to me by Michael Pitt.) The LOW moved generally north-northeastward during the evening of the 7th and early morning of the 8th. Early on 8 September satellite imagery and surface observations indicated that the broad area of low pressure east of the northern Bahamas was becoming better organized and a reconnaissance plane was scheduled to investigate the system later in the day. At 1200 UTC the broad center of the disturbance was located approximately 500 nm southeast of Cape Hatteras, and at 1500 UTC the first advisory on Subtropical Depression Eight was issued. A change was made late in 2001 to NHC's operational procedures to the effect that any subtropical depression or storm for which warnings were issued would be numbered sequentially with the next tropical cyclone number. The second change made to the operational procedures was that when a system was designated as a subtropical storm (winds of gale force or higher), it would be assigned the next available tropical cyclone name. The reconnaissance flight into the system found 40-kt winds at 450 m to the northeast of the center along with a 1006-mb central pressure, so the depression was upgraded to Subtropical Storm Gustav at 2100 UTC. Since the forecast track brought Gustav's center almost to the Mid-Atlantic Coast within 36 to 48 hours, a tropical storm watch was issued for portions of the North Carolina coastline. B. Track and Intensity History ------------------------------ By 0000 UTC on 9 September Gustav's center was located about 335 nm south-southeast of Cape Hatteras, moving west-northwestward at 13 kts. As the day progressed Gustav continued to become better organized and very slowly began to look more like a tropical cyclone. Baroclinic cloudiness to the east began to separate and move away from the cyclone and anticyclonic outflow became better defined. Deep convection also became better established near the center with morning visible imagery revealing a partially-exposed center on the eastern edge of the deep convection. Reconnaissance data, however, indicated that there was at best only a weak warm core at 850 mb and the radius of maximum winds remained on the order of 75-100 nm, so Gustav remained classified as a subtropical storm. By 2100 UTC the storm's center had reached a point about 190 nm south-southeast of Cape Hatteras, and the west- northwestward motion had slowed to 8 kts. An early afternoon reconnaissance flight found maximum flight-level winds of 53 kts, and reports from NOAA buoy 41002 indicated that the central pressure had dropped to 999 mb. Based on this the MSW remained at 40 kts--where it had been pegged since 0900 UTC. Gustav had strengthened slightly by 10/0000 UTC--the MSW was upped to 45 kts based on a reconnaissance report of 55-kt winds at 450 m to the southwest of the center along with a central pressure of 996 mb. As of the 0900 UTC advisory Gustav still exhibited little evidence of a warm core and the system remained underneath an upper-level LOW. However, the discussion bulletin noted that there was evidence that the core was about to become better organized. An intermediate advisory at 1200 UTC reclassified Gustav as a tropical storm based on aircraft reports that an inner core of strong winds was developing. Tropical Storm Gustav was then located approximately 100 nm due south of Cape Hatteras, moving northward at 8 kts with maximum winds of 50 kts. During the morning a reconnaissance plane found peak winds at flight-level of 62 kts with a central pressure of 987 mb. By afternoon convection had wrapped almost completely around the center and the central pressure had dropped to 984 mb. The center of Gustav passed just east of Cape Hatteras during the afternoon and at 2100 UTC was located only about 17 nm east-northeast of the cape. The AWS at Diamond Shoals reported a SLP of 984.8 mb during the afternoon, and Cape Hatteras reported a wind gust of 68 kts around 2200 UTC. The 11/0300 UTC discussion noted that Gustav continued to appear better organized and looked more like a tropical cyclone. A well-defined convective band had wrapped completely around the center, but there were not yet any indications of an eye forming. The good news for the U. S. coast was that Gustav had become embedded in southwesterly flow ahead of a developing trough and was beginning to accelerate away from the main- land. The center of Gustav at 0300 UTC was located approximately 105 nm northeast of Cape Hatteras and moving northeastward at 16 kts. The MSW had increased to 55 kts and Gustav was still forecast to reach hurricane intensity before becoming extratropical. The MSW was bumped up to 60 kts at 11/0900 UTC based on CI estimates of 65 and 55 kts from TAFB and SAB. However, shortly after the issuance of that advisory, a reconnaissance plane found 80-kt winds at 850 mb southwest of the center with a central pressure of 975 mb. Visible imagery showed a well-developed tropical cyclone with convection wrapped all the way around the center. Gustav was upgraded to a 65-kt hurricane at 1200 UTC, located about 225 nm southeast of New York City. This is the latest date for the formation of the Atlantic season's first hurricane since 1941 when the first hurricane did not form until 18 September. Other more recent late- appearing first hurricanes were Diana of 1984 (10 September) and Erin just last year (9 September). By the afternoon of 11 September Hurricane Gustav had accelerated and begun extratropical transition. However, a reconnaissance aircraft around midday found a central pressure of 964 mb and peak flight-level winds of 104 kts, and the stepped-frequency microwave radiometer on the NOAA research aircraft measured 71-kt surface winds. Based on this data, the MSW for Gustav was upped to 80 kts at 2100 UTC, and the forecaster writing the discussion remarked that this was possibly conservative. The hurricane was then located approximately 240 nm south-southwest of Halifax, Nova Scotia, and racing northeastward at 33 kts. At 0300 UTC on 12 September Gustav was near eastern Nova Scotia about 80 nm south-southwest of Sydney and moving northeastward at 40 kts. The MSW was reduced to 70 kts, and the storm was beginning to look ragged as it began to lose its tropical characteristics. The final NHC advisory on Gustav was issued at 12/0900 UTC. The center was then estimated to be inland in Newfoundland about 60 km south-southwest of Stephenville. The storm was still of hurricane intensity, but was rapidly losing its tropical characteristics as it interacted with a non-tropical upper-level LOW. The cloud top temperatures had warmed considerably and what little convection remained was displaced northeast of the LLCC. The powerful storm subsequently turned northward and slowed as it moved off the east coast of Labrador. By midday on the 14th the system had weakened into a 40-kt gale in the Labrador Sea about halfway between northern Labrador and southern Greenland. C. Additional Discussion ------------------------ Chris Fogarty, a Research Meteorologist with Environment Canada and currently a doctoral student at Dalhousie University, prepared and sent a report on Hurricane Gustav. Portions of Chris' summary are included below. A special thanks to Chris for sending me the summary and for permission to use it. (1) Storm Structure ------------------- This event was handled rather well by the numerical models because essentially it behaved like a strong extratropical system. The approaching trough from the west was digging over New England and formed its own LOW over Maine. The baroclinic energy from this was eventually transferred to Gustav, whose center remained intact as it made landfall. On a large scale the system appeared extratropical, yet had a tropical center which was rapidly becoming sheared and losing its warm core. Most of the rainfall was actually not related to the core rains of Gustav, but from the moist boundary between Gustav and the baroclinic development to its northwest. Comparison of surface data, radar and satellite imagery suggest there was a large degree of tilt with Gustav such that the mid-level center was sheared to the east or northeast of the surface center. This pattern also occurred during the similar extratropical transition of Hurricane Michael in October, 2000. (2) Landfall Details -------------------- At this time both agencies (NHC and CHC) are agreeing Gustav was technically a hurricane at landfall. There is some uncertainty as to which community in southern Cape Breton should be classified as the landfall point. This owes to lack of surface data and difficulty inferring the surface center from radar and satellite images. There was some degree of decoupling between the surface center and mid-level center. The closest community would likely be St. Esprit at 1:30 am ADT September 12th (12/0430 UTC) with a storm central pressure of 960 mb, moving northeast around 35 to 40 knots. Hart Island on the southeastern tip of mainland Nova Scotia reported a sea level pressure of 961.4 mb at 45 minutes past midnight September 12th (12/0345 UTC). Hart Island was about 30 km north of the storm center. D. Meteorological Observations ------------------------------ (1) Wind Observations --------------------- Gustav was a very complicated system with strongest winds displaced well away from its center at the time of landfall. Damaging winds occurred as far west as Maine where large trees were toppled. Prince Edward Island seemed to take the brunt of the storm--not Cape Breton Island as one might expect. There were also very high winds south of the storm track on Sable Island where gusts reached 66 knots with a sustained wind of 48 kts. Over land, many stations recorded gusts over 50 kts, and in a few cases gusts near 65 knots. Winds did not appear to be very high near the center of the storm as it crossed Cape Breton. Sydney's winds did not really pick up until several hours after the storm passed, and barely gusted to 30 knots during its passage. A Canadian buoy just north of the storm track reported gusts to 60 kts, and St. Paul's Island on the northernmost part of Nova Scotia recorded a peak gust of 66 kts. Charlottetown's peak winds at the height of the storm were sustained 35 kts, gusting to 52 kts. Finally, St. Lawrence, Newfoundland, recorded a peak gust of 70 kts. (2) Rainfall Observations ------------------------- There were very heavy rainfall amounts across the entire Atlantic Canadian region. Some of the highest amounts were along a swath which was left of and parallel to the storm track over Prince Edward Island and Central Nova Scotia. A few localities received over 100 mm (4") of rain in a twenty-four hour period. This is impressive considering how fast the storm was moving. Below are some noteworthy storm-total rainfalls which fell over a 24-hour period: Lyon's Brook, Nova Scotia 108 mm - near New Glasgow Ashdale, Nova Scotia 105 mm - Hants County Liverpool, Nova Scotia 102 mm Middleboro, Nova Scotia 100 mm - near Pugwash, northern Nova Scotia Halifax Airport, Nova Scotia 94 mm Charlottetown, PEI 70 mm Halifax (Shearwater) 56 mm Sydney, Nova Scotia 56 mm (3) Storm Surge --------------- Higher than normal water levels were experienced along all the coastlines of Prince Edward Island, northern and eastern Nova Scotia, and eastern New Brunswick. Some localized coastal flooding was reported from each of the three Maritime Provinces. In particular, the southern coast of Prince Edward Island narrowly missed a serious surge event when the high point of the surge (over 1400 mm at Charlottetown) occurred 3-4 hours after the high astronomical tide of the day--at which point only a 700-mm surge was occurring. Had the two events coincided, the total water level at Charlottetown would have likely matched the all-time record value and a significant flooding event would have resulted in downtown Charlottetown (similar to or worse than the flood from the January, 2000, superstorm surge). E. Damage and Casualties ------------------------ Hardest hit was Prince Edward Island where whole trees were toppled and there was some local flooding. Some docks were damaged in Eastern New Brunswick. High-sided vehicles were prohibited from crossing the Confederation Bridge between Prince Edward Island and New Brunswick, and ferry service was suspended between Nova Scotia and Newfoundland. There were scattered power outages from limbs and trees falling onto lines. In the Halifax area there was only some leaf litter after the storm went through--winds did not gust much more than 35 kts. A report on Hurricane Gustav along with some pictures can be found on the website of the Canadian Hurricane Centre at the following link: (Report written by Gary Padgett with significant contributions by Chris Fogarty) TROPICAL STORM HANNA (TC-09) 12 - 16 September ---------------------------------------- A. Storm Origins ---------------- On 10 September surface observations indicated the presence of a broad area of low pressure located off the Texas coast. The large area of disturbed weather covered much of the Gulf of Mexico and was first mentioned in a STWO issued at 10/1530 UTC. Remarks in the 11/1805 UTC Tropical Weather Discussion noted that an upper-level LOW was combining with a 1008-mb LOW over the central Gulf of Mexico to produce an extensive area of showers and thunderstorms over the region which were spreading over the Florida Peninsula. The area was considered a possibility for tropical development. However, due to the proximity of the upper-level trough there was also the potential for subtropical cyclone development in a manner similar to the early stages of Hurricane Gustav. The disturbance had formed into a depression by 12/0300 UTC while located near 26.5N, 86.5W, or about 240 nm south of Eglin AFB, Florida. An Air Force Reserves unit aircraft at this time found a CP of 1001 mb and peak 450 m flight-level winds of 40 kts. However, the depression was not particularly impressive-looking in satellite imagery with little deep convection near the LLCC and little curvature in the convective bands to the south. The initial movement was toward the north-northeast at 4 kts, but the system's motion was generally slow and erratic for several days. A reconnaissance aircraft reported flight-level winds of 45 kts in the southeast quadrant shortly after 0300 UTC on the 13th, and a later pass through the system revealed 50-kt winds north of the centre. These observations, along with two surface reports of 35-kt winds, led to the upgrading of TD-09 to Tropical Storm Hanna at 13/0900 UTC. Hanna was then centred approximately 220 nm south- southwest of Pensacola, Florida, moving northwestward at 7 kts with a MSW of 40 kts. B. Track and Intensity History ------------------------------ Early on 14 September Hanna was still meandering and the storm had changed little other than an increase in the MSW to 45 kts based on a reconnaissance report of 58-kt winds at 850 mb at 13/2346 UTC. This wind observation was made about 85 nm southeast of the centre and was the only evidence for 45-kt surface winds. This represents the peak intensity for Tropical Storm Hanna. The storm existed in a sheared environment with most of the tropical storm-force winds located to the east and southeast of the exposed centre. Forecast models were predicting Hanna to move toward the northeast in response to the south- westerly airflow of a mid-level trough, and by 14/0900 UTC Hanna had finally taken the anticipated northeastward track toward the Mississippi/Alabama coastline. A reconnaissance aircraft reported a peak flight-level wind at 925 mb of 57 kts, so the MSW appeared to be holding steady at 45 kts, even though the exposed circulation was becoming deformed and elongated. Tropical Storm Hanna made landfall near the Mississippi/Alabama border around 1500 UTC on the 14th. Shortly before landfall a reconnaissance plane measured a central pressure of 1002 mb and a peak flight-level wind of 59 kts just east of the centre, so the storm apparently maintained its 45-kt intensity until landfall. Hanna was downgraded to a tropical depression at 1800 UTC while located in the vicinity of Mobile, Alabama, and the final advisory was issued at 14/2100 UTC, placing the weakening centre about 65 km northeast of Mobile and moving northeastward at 11 kts. Responsibility for issuing information on Hanna's remnants was then assumed by HPC in Maryland. The LOW was followed northeastward across the states of Alabama, Georgia, South Carolina and into eastern North Carolina. The final storm summary from HPC was issued at 0900 UTC on 16 September and placed the very weak centre near Hickory, North Carolina, or about 50 km northwest of Charlotte near 35.6N, 81.3W, and moving east-northeastward at 22 kts. What ultimately happened to the surface remnants of Hanna is somewhat of a mystery to the authors. The MPC High Seas Forecast for 16/1800 UTC mentioned an inland 1014-mb LOW near 36N, 77W, moving east-northeastward at 20 kts. Winds to 25 kts and seas to 8 ft were forecast within 240 nm in the south and southeastern quadrants. Whether this was the same centre which had been Hanna or a new baroclinic development is uncertain, but the 1800 UTC position suggests it could have been Hanna. However, the 17/0000 UTC forecast did not refer to this LOW, although it did forecast a LOW in 24-hours to be near 37N, 69W. Because of this uncertainty, the track for Hanna in the accompanying cyclone tracks file ended with the final HPC summary. C. Meteorological Observations ------------------------------ The Dauphin Island weather station reported a gust of 45 kts shortly before 14/1200 UTC, and Pensacola recorded a gust of 54 kts around 1500 UTC. Hanna brought torrential rains to the Southeastern United States. Some selected precipitation totals from the HPC storm summaries are tabulated below: Location Amount (mm) Time Period ------------------------------------------------------------------------- Ocala, FL 91 36 hours ending at 15/0000 UTC Destin, FL 97 " Valparaiso, FL 107 " Panama City, FL 101 " Hurlburt Field, FL 91 " Donalsonville, GA 371 24 hours ending at 15/1100 UTC Blakely, GA 184 " Newton, GA 152 " Chipley, FL 206 " Marianna, FL 128 " Greenville, SC 63 3 hours ending at 15/2100 UTC Spartanburg, SC 60 " Greenville, SC 111 24 hours ending at 16/0000 UTC Marianna, FL 104 " Anderson, SC 95 " Albany, GA 88 " D. Damage and Casualties ------------------------ The Monthly Summary for September on TPC/NHC's website indicates that three deaths were attributed to Tropical Storm Hanna, but the location of these is not known to the authors. Also, when the NHC summary was written in early October, the monetary damage estimate due to Hanna had not been determined. The particulars on the fatalities and damage will be available later when the official NHC report for Hanna has been completed. (Report written by Kevin Boyle and Gary Padgett) HURRICANE ISIDORE (TC-10) 14 - 27 September ------------------------------------- A. Storm Origins ---------------- The first mention of the pre-Isidore disturbance was in the STWO issued at 0930 UTC on 11 September (a tropical wave located 435 nm west-southwest of the Cape Verdes). The wave had likely left the African coast around 9 September. This system moved westward across the tropical Atlantic and slow development was anticipated, as indicated in the STWOs. Despite being situated in a dry air environment, visible satellite images on the morning of 12 September indicated that the wave was slowly becoming better organized. By 13/1530 UTC the disturbance had moved westward to a position approximately 520 nm east of the Windward Islands. Satellite images early on 14 September indicated that shower/thunderstorm activity had increased significantly, although at the time there was no evidence of a LLCC. As the wave approached the Lesser Antilles a US Air Force Reserves' reconnaissance plane was sent to investigate the system and found a small closed circulation with 20-25 kt winds and a CP of 1009 mb located near the southwestern tip of the island of Trinidad. High resolution visible images indicated that the system had a large envelope, curved bands, and an excellent outflow pattern. Based on this information, the first warning on Tropical Depression Ten was issued at 14/2100 UTC. Surface observations and satellite pictures early on 15 September indicated that TD-10 was moving westward at 20 kts or more over northern Venezuela. This overland trajectory resulted in a decrease in deep convection near the weakening LLCC. Surface observations from the ABC Islands (Aruba, Bonaire, Curacao) showed only a slight wind shift from east-northeast to east-southeast. The last advisory on this stage of TD-10 was issued at 15/2100 UTC, the system having degenerated into a tropical wave. The remnants of TD-10 were monitored in the STWOs because of the strong possibility of a tropical depression reforming. A plane investigating the strong tropical wave at 16/1405 UTC found no signs of a closed LLCC, although the vigorous tropical wave had winds of up to tropical storm force. At 16/2130 UTC the system was located about 130 nm east-southeast of Jamaica. A Tropical Weather Discussion late on the 16th noted that "....the last few available images of visible imagery indicated that a LLCC may be trying to form approximately 130 nm southeast of southern Jamaica with low-level cloud elements beginning to wrap back around to the east near 15N, 76W. Extrapolated inflow to the southeast of the main convection also indicates that a second low/mid- level center may be trying to form just south of Hispaniola." A reconnaissance aircraft found a closed LLCC on the morning of the 17th and advisories were re-initiated on Tropical Depression Ten at 17/1500 UTC, placing the centre about 125 nm south of Kingston, Jamaica, with the MSW estimated at 30 kts. B. Track and Intensity History ------------------------------ Moving northwestward at 5 to 6 kts early on 18 September, TD-10 slowly strengthened into a 35-kt tropical storm. The system was upgraded to Tropical Storm Isidore in an intermediate advisory at 0600 UTC. The broad, elongated centre was estimated to be about 90 nm southwest of Kingston, Jamaica. The upgrade was based on an aircraft report of 450-m flight-level winds of 46 kts about 65 nm east-northeast of the LLCC. By 18/2100 UTC the MSW had risen to 50 kts as Isidore continued to organise and strengthen. The LLCC was relocated to 19.0N, 78.8W, at this time and aircraft reported a CP of 999 mb. At 19/0800 UTC a reconnaissance plane reported a partial eyewall and found that the CP had fallen to 990 mb. The MSW was raised to 55 kts, and to 60 kts six hours later. Isidore became the second hurricane of the 2002 Atlantic season at 19/2100 UTC after an aircraft reported peak flight-level winds of 76 kts with estimated surface winds of 70 kts and a CP of 984 mb. The 19/2100 UTC advisory intensity was set at 65 kts with the centre located near 20.6N, 82.0W, or about 85 nm southeast of the Isle of Youth, Cuba, and moving northwestward at 8 kts as it was guided by a mid to upper- level ridge over Florida and the Bahamas. The MSW had risen to 75 kts (Dvorak T-numbers 4.5 and 5.0) by 0300 UTC on 20 September. Isidore had expanded into a large system with tropical storm-force winds extending 125 nm from the centre. Winds of up to 25 kts were being experienced in the Florida Keys as the core of the hurricane was pounding western Cuba with winds of 85 kts. The eye of Isidore, with a CP of 964 mb (as measured by a reconnaissance plane), moved inland very near La Fe, Cuba at 20/2100 UTC. Six hours later Isidore had moved into the southeastern Gulf of Mexico with the MSW changing very little due to the less mountainous terrain of western Cuba. In fact, the storm had strengthened into a Category 3 hurricane with a MSW of 100 kts by 21/1500 UTC after it had begun a period of rapid intensification, accompanied by a more westward drift towards the Yucatan Peninsula. Hurricane Isidore was centred at the time approximately 65 nm west-northwest of Cabo San Antonio on the western tip of Cuba. The 100-kt intensity was supported by a 100-kt dropsonde report at 21/1200 UTC plus Dvorak intensity estimates of 102 kts from TAFB, SAB and AFWA. (Editor's Note: I have learned from NHC that Isidore's intensity over western Cuba has been lowered to Category 1 levels for the Best Track.) The MSW had reached 110 kts (the peak for the storm) by 2100 UTC on 21 September, but strengthening leveled off--perhaps due to an eyewall replacement cycle. Aircraft observed a smaller eye and a double maximum wind band structure, and both the Cancun radar and satellite data showed an outer convective ring surrounding the eye. The plane reported a CP of 936 mb at 0700 UTC, 22 September, and 934 mb a few hours later. However, the MSW remained pegged at 110 kts when normally satellite estimates of T6.5 and a 934-mb CP would translate to a 125-kt to 130-kt system. During the time of its peak intensity Isidore was moving west- ward just offshore and parallel to the northern coast of Mexico's Yucatan Peninsula. On the afternoon of the 22nd, the eye of the storm made a sudden hook to the left and moved inland over the extreme northern Yucatan coast around 23/0000 UTC about 30 km east of Merida. The MSW was still estimated at 110 kts at landfall. The hurricane was moving on a southwesterly path at 4 kts at this time in response to mid-level ridging to the west-northwest. Interaction with the land mass of Yucatan induced a rapid weakening and the MSW had dropped to 65 kts by 23/0900 UTC, and to below hurricane strength six hours later. Satellite imagery indicated that most of the deep convection was occurring mostly over the southern portion of the circulation with scattered and disorganized amounts elsewhere. Tropical Storm Isidore performed a loop during 23 September inland over the Yucatan Peninsula, the initial southerly motion earlier in the day turning northerly by 23/2100 UTC. During this time the MSW weakened to 45 kts, and by 24/0300 UTC Isidore was barely a tropical storm with maximum winds estimated at only 35 kts. Broad mid and upper-level troughing over the central US and western Gulf of Mexico and a developing ridge extending from the northwestern Caribbean towards Florida meant a change to a north to north-northeast heading for the slow-moving Isidore. Satellite images and surface observations from Merida, Mexico, indicated that the poorly-defined LLCC was located just to the north of Merida at 0900 UTC, 24 September, and was about to move back over water. Satellite imagery depicted Isidore as a very large swirl of low to mid-level clouds (that covered all the Gulf of Mexico) with the nearest convective bands far from the centre to the northwest and southwest of the LLCC. However, the tropical cyclone lacked an inner core, and this was well backed up by a reconnaissance mission which indicated that the radius of maximum winds was nearly 120-125 nm from the centre. Based on the information from the plane, as well as CI estimates of 55 kts from SAB and AFWA, the MSW was increased to 50 kts at 24/1500 UTC. Isidore at the time was centred approximately 70 nm north-northwest of Merida, or about 420 nm south of the Louisiana coast. Despite the centre of Isidore moving northward over the warm waters of the Gulf of Mexico under favourable developmental conditions, the storm failed to tighten up its inner core. This was the reason why Isidore failed to intensify into a hurricane again. Surface observations, Air Force Reserves' reconnaissance planes, and a NOAA G-IV jet indicated that the strongest winds remained located more than 100 nm to the northeast of the LLCC with a large area of light winds around the centre. Water vapour imagery indicated that dry air was being entrained into the southern portion of Isidore's circulation on 25 September. Also, a developing upper-level LOW was centred to the storm's southwest, likely inhibiting further strengthening. At 25/2100 UTC the MSW was upped slightly to 55 kts, based on a report from a ship (located well northeast of the centre) of sustained winds of 56 kts, gusting to 71 kts. The CP measured by a reconnaissance aircraft around this time was 989 mb. Due to the large circulation, tropical storm-force winds were felt on the southeastern Louisiana coast as early as 0300 UTC on 26 September. These strongest winds extended 90-100 nm from the LLCC. Tropical Storm Isidore made landfall at 26/0900 UTC just west of Grand Isle on the Louisiana coast with a MSW of 55 kts. This was the peak intensity of Isidore during the second part of its career in the Gulf of Mexico. In satellite imagery Isidore was looking better-organized with strong convection near the LLCC, and was probably on its way to becoming a hurricane until it ran out of energy by moving inland. The large circulation accelerated to the north-northeast, embedded in the south- westerly flow ahead of a trough. A steady weakening occurred after landfall and Isidore became a 30-kt depression on the final NHC advisory, issued at 26/2100 UTC. The depression was centred about 80 km north- northeast of Jackson, Mississippi, and moving northward at 22 kts. HPC assumed responsibility for issuing storm summaries on the remnants of Isidore as long as there remained a threat from flooding. The fourth and final summary from HPC was issued at 2100 UTC on 27 September. The depression had become extratropical over western Pennsylvania and was speeding northeastward at 35 kts. C. Meteorological Observations ------------------------------ At Isidore's peak intensity (110 kts, 934 mb) on 22 September in the southern Gulf of Mexico, hurricane force winds reached outward from the centre 45 nm in the northern semicircle and 30 nm in the southern quadrants. Gales extended out 175 nm north of the centre and from 100-125 nm to the south. On 25 September, when Isidore was a large sprawling tropical storm churning northward through the central Gulf, gales reached out 275 nm to the northeast of the centre and 200 nm to the southeast. As Isidore was crossing western Cuba, Cabo San Antonio reported maximum sustained winds of 73 kts at 20/2100 UTC. On the afternoon of 22 September, a ham radio report from the Yucatan indicated sustained winds of 61 kts, gusting to 78 kts, near Merida. During the afternoon of the 25th a ship located northeast of the centre reported sustained winds of 56 kts, gusting to 71 kts. Around 26/0000 UTC, the C-MAN station at Southwest Pass (near the mouth of the Mississippi River) recorded sustained winds of 43 kts with a peak gust of 52 kts. (NOTE: Some reconnaissance reports were included in the narrative above. Additional information reported by the reconnaissance flights can be found in the discussion bulletins issued with each regular advisory. These are archived on NHC's website at the following URL: ) Following are some rainfall accumulations reported in the storm summaries issued by HPC: (1) 24-hour totals ending at 2300 UTC on 26 September ----------------------------------------------------- McComb-Pike County, Mississippi 194 mm Tupelo, Mississippi 176 mm Hattiesburg, Mississippi 119 mm (2) 24-hour totals ending at 0000 UTC on 27 September ----------------------------------------------------- New Orleans-Audobon, Louisiana 162 mm New Orleans-International Airport 143 mm Jackson, Tennessee 148 mm NWS Memphis, Tennessee 80 mm Evergreen, Alabama 88 mm (3) Storm Totals ----------------------------------------------------- New Orleans-Audobon, Louisiana 299 mm New Orleans-International Airport 292 mm McComb-Pike County, Mississippi 258 mm Tupelo, Mississippi 224 mm Jackson, Tennessee 210 mm Hattiesburg, Mississippi 209 mm Rough River Lake, Kentucky 164 mm Woodbury, Kentucky 157 mm Evergreen, Alabama 147 mm Louisville APT, Kentucky 134 mm Scottsburg, Indiana 126 mm Leavenworth, Indiana 124 mm NWS Memphis, Tennessee 102 mm Cincinnati, Ohio 91 mm There were some unofficial reports of over 500 mm of rain recorded in the New Orleans area. D. Damage and Casualties ------------------------ In Cuba some areas received in excess of 600 mm of rain during the first 24 hours of Isidore's passage, and coastal storm surges reached from 2.5-3.75 m above normal tide level in some areas. Some 280,000 people as well as thousands of cattle were evacuated as the storm approached. Flooding from the heavy rains was particularly severe in the municipalities of San Juan y Martinez, Sandino, and Guane with reports of destroyed houses, roofs blown off, disrupted electricity supplies, and blocked roads. Some 134 tobacco drying houses were affected, damaging valuable tobacco stocks, and at least 3000 tons of citrus fruit were reported lost. Earlier, rains from Isidore had pounded Jamaica, no doubt causing some flooding, but no reports from that island on the effects of Isidore were available to the author. Mexico was especially hard hit by Isidore, as the storm landed on the northern Yucatan coast as a Category 3 hurricane. The impact was most severe in the state of Yucatan, but the states of Quintana Roo, Campeche, and Chiapas were also significantly affected by the hurricane. In Yucatan state alone over 500,000 persons were adversely affected by Isidore. Almost 23,000 houses lost their roofs and 12,800 houses were destroyed. (Another report stated that 33,000 village houses were complete destroyed.) Barns, warehouses and storage bins were impacted with 75% being destroyed or severely damaged. One report indicated that three persons were killed as a result of the hurricane, and 240 injuries were reported. Agricultural losses in Yucatan state were staggering: 80% of maize (corn) production land (70,000 hectares) was destroyed and still flooded almost a month after the hurricane; 40,000 hectares of fruit trees were lost; 8.5 million poultry drowned, representing 90% of the poultry production in the state; and 80% of the pigs disappeared in the floods. The capital city of Yucatan state, Merida, was badly damaged with many trees uprooted, roofs ripped from houses, 70% of the power lines down, and 80% of the city flooded by waters from 0.2 to 0.3 m deep. Some 70,000 persons were evacuated from high risk coastal areas. The city of Puerto Progreso was also severely impacted by Isidore. A week after the storm water supply systems in the impacted areas were functioning at only 50% of their total capacity. In the state of Campeche from 15,000 to 20,000 village houses were destroyed either by direct impact of Isidore or by the following floods. Over 30,000 head of cattle were lost; 63,500 honey bee production apiaries were destroyed; and 100,000 hectares of agricultural land lost. New Zealand-based storm chaser (or more appropriately, natural disaster chaser) Geoff Mackley was in Progreso as Isidore made landfall. A brief description of Geoff's experiences plus some striking photos showing the damage caused by Isidore may be found at the following URL: < http://www.rambocam.com/isidore.html > In the United States there were four drowning deaths caused by Isidore, and damage has tentatively been estimated at $200 million. Losses to agricultural crops were substantial in some areas of the Southeast as the storm's heavy rains came during or just before harvest time. Storm chaser Jim Edds from the Florida Keys was in the Mobile, Alabama, area during Isidore and has placed on his website some pictures depicting flooding along the Mobile Bay Causeway due to the storm surge. The URL is: < http://www.hurricanechase.com > Many additional reports, articles, and press releases on Isidore's effects can be found on the ReliefWeb homepage at the following URL: E. Additional Discussion ------------------------ Hurricane Isidore's peak MSW of 110 kts vs a minimum CP of 934 mb serves as a good illustration of the individuality of storms and the fact that there is not a one-to-one correspondence between the MSW and CP--a notion which seems to be fairly prevalent among the public and media. In the Atlantic basin a 934-mb central pressure would normally support a MSW of 125-130 kts. However, the maximum intensity of a hurricane depends on several factors, including the central pressure, the environmental pressures in the vicinity of the storm, and the distance over which the maximum pressure fall occurs. Additionally, peculiarities of the internal structure of a given hurricane can play a role in determining the maximum intensity, and also the storm's translational speed can help to augment the wind field on the right-hand side of the cyclone (with respect to its direction of motion). Isidore was a relatively large, slow-moving hurricane located in a region of lower-than-normal sea level pressures. By way of contrast, Hurricane Georges in September, 1998, boasted 135-kt winds with a CP of 937 mb at its peak intensity well east of the Lesser Antilles. Georges was a smaller storm in areal extent than Isidore, and was zipping along in the easterlies at twice the speed of Isidore with a rather strong ridge of high pressure to its north. Another factor which plays a role in the strength of the surface winds is the intensity of the core convection. Intense convection helps to bring the extreme winds occurring at higher elevations down to the surface. With other factors being equal, a strengthening hurricane with intense convection can have a significantly higher MSW than a steady-state or weakening storm with the same central pressure but which has weaker convection. According to Rich Henning, a member of the 53rd Weather Reconnaissance Squadron (the Hurricane Hunters), Isidore's central convection was not particularly impressive, especially around the time it made landfall. Rich was on a flight into the storm as the centre moved onshore in the Yucatan Peninsula, and he stated that while the eye was extremely well-formed with excellent outflow and no sign of vertical shear (i.e., an optimum dynamical environment), there was very little deep convection near the eye, most of it being well to the east over the peninsula and west over the Bay of Campeche. Rich attributes this in part to upwelling just off the northern Yucatan shoreline, leading to SSTs a few degrees cooler than farther east in the Yucatan Channel. (Thanks to Rich for sharing his observations and thoughts on Isidore.) (Report written by Kevin Boyle and Gary Padgett) TROPICAL STORM JOSEPHINE (TC-11) 17 - 19 September -------------------------------------------- An area of low-pressure centred about 740 nm east of Bermuda was first mentioned in a Tropical Weather Outlook (TWO) from TPC/NHC at 0930 UTC on 16 September. The LOW was located in an environment of high surface pressures, and slow development of the system was forecast. The TWO issued at 1530 UTC 17 September indicated that the LOW was acquiring tropical characteristics about 600 nm east of Bermuda. Satellite images showed that the LOW contained enough convection to qualify as a tropical cyclone, and advisories were initiated on Tropical Depression Eleven at 2100 UTC, 17 September. The system was embedded in an upper-level trough and moving slowly northward at 7 kts at the time. The depression was initially not forecast to reach tropical storm intensity; however, based on an 18/0300 UTC report of winds of 37 kts from ship PDKK, Quik- Scat and SSM/I winds of 35 kts, and Dvorak satellite estimates of T2.5 from TAFB, TD-11 was upgraded to Tropical Storm Josephine at 0900 UTC when located approximately 650 nm east-northeast of Bermuda. The system was then moving north-northeastward at 12 kts. Josephine reached a peak intensity of 35 kts on the 18/0900 UTC warning and, although there were still intermittent bursts of convection near the LLCC, dry air intrusion at mid-levels combined with increasing westerly and southwesterly upper-level shear prevented further develop- ment. However, the pressure gradient remained very tight on the east side as Josephine moved generally northeastward on the western side of a large HIGH centred to the northeast and in advance of an approaching mid-latitude trough. Josephine accelerated northeastwards between these features towards cooler waters and increasing southwesterly shear, and was absorbed into the frontal system well to the east of Newfoundland on 19 September. A surprise came when ship C6LV3 reported 50-kt winds at 1200 UTC about 85 nm southeast of the centre. This was the reported MSW on the final advisory issued by NHC at 1500 UTC, which placed the centre of the now-extratropical Josephine at 42.5N, 42.5W, or about 550 nm west-northwest of the northwesternmost Azores, moving northeast- ward at 25 kts. This ship report suggests that Josephine was very possibly stronger during its tenure as a tropical storm than estimated in the advisories, especially considering its rather rapid translational speed. The post-Josephine extratropical LOW had been absorbed into another LOW to the north by the 20th. (Report written by Kevin Boyle) HURRICANE KYLE (TC-12) 20 September - 18 October --------------------------------------------- Even though Kyle was a hurricane for only 2.5 days, it persisted over the subtropical Atlantic for 22.25 days, becoming the third longest-lived Atlantic basin tropical cyclone on record. Hurricane Ginger (1971) holds the Atlantic longevity record of 27.25 days, followed by Hurricane Inga (1969) with a lifespan of 24.75 days. Kyle's track was very similar to Hurricane Olga of 2001 (as well as to the aforementioned Inga and Ginger) in that it wandered aimlessly for days over the subtropics with several fluctuations in intensity. Kyle was upgraded to tropical storm intensity five separate times during its life. A. Storm Origins ---------------- Long-lived Kyle began as a non-tropical LOW that formed east-southeast of Bermuda near 28.4N, 51.7W, on 20 September. The LOW had developed some organized convection, but a TRMM overpass at 20/1601 UTC indicated that the maximum winds were at least 100 nm from the centre. Based on this information TPC/NHC issued the first warning on Subtropical Depression Twelve. Initially moving northward at 10 kts, the subtropical depression became better organized and was upgraded to Subtropical Storm Kyle at 21/0900 UTC when centred about 700 nm east of Bermuda. Kyle was situated in a favourable environment with 26-27 C SSTs and light vertical shear with a good anticyclonic outflow at upper levels. Continuing in a northward direction, Subtropical Storm Kyle decelerated to a virtual standstill in response to increased ridging to the north. B. Track and Intensity History ------------------------------ Kyle had fully transformed into a tropical storm by 2100 UTC, 22 September, as deep convection had properly developed over the centre and the circulation had become more detached from a frontal zone. Kyle was then centred approximately 775 nm east of Bermuda and stationary. The cyclone phase analysis from Pennsylvania State University plus AMSU data showed that the system had developed a warm core. The MSW was estimated at 40 kts but was lowered to 35 kts at 23/0300 UTC as T-numbers from TAFB and SAB were 2.5 at this time. Kyle began to move toward the southwest on 23 September as pressure built to the north of the system. This southwestward heading was maintained for several days on the east side of the northeast-southwest oriented mid-level ridge near Bermuda. Kyle had been undergoing shear which was pushing the associated convection to the west of the LLCC, but these conditions began to relax on 24 September. In response to the more favourable conditions, the MSW rose to 55 kts, convection wrapped around the centre with cooling cloud tops, and a banding-type eye feature appeared. Hurricane intensity was reached late on 25 September based on the banding eye and Dvorak intensity estimates of T4.0 or 65 kts. Kyle by this time had reached a point approximately 525 nm east-southeast of Bermuda. Kyle had only a day or so to strengthen before northwesterly shear began to affect the system. However, the cyclone reached a peak intensity of 75 kts at 0900 UTC on 26 September when located roughly 450 nm east-southeast of Bermuda, based on Dvorak satellite intensity estimates of T4.5 from TAFB and SAB. Water vapour imagery at 27/0300 UTC showed the northerly wind shear about to impact the hurricane. The eye became less distinct and satellite estimates began to drop slightly early on the 27th. Kyle appeared to be fighting off the shear for awhile and the MSW remained at 75 kts. However, the circulation became distorted east-west, and coupled with the advection of dry air into Kyle from the north, the MSW began to fall steadily. A microwave pass at 27/1247 UTC showed that the upper-level centre was displaced about 15 nm south- southwest of the LLCC. The shearing conditions were now pushing Kyle on a more west-southwestward track, still trapped between a mid to upper- level ridge located between Bermuda and the southeastern US and a second ridge lying along 17N in the tropical Atlantic. Kyle was downgraded to a tropical storm at 28/1500 UTC when located about 375 nm south-southeast of Bermuda. The storm had reached the southernmost point of its track and had begun a slow westward drift. The completely-exposed LLCC then turned to the northwest during 29 September with the MSW dropping to 40 kts. Late on the 29th Kyle began a slow northerly crawl, and this continued on the 30th before the system came to a halt later that day near 29.8N, 64.8W, or approximately 150 nm south of Bermuda. CIMSS analyses at 30/0900 UTC indicated that the northeasterly shear that had plagued Kyle had begun to ease significantly and deep convection correspondingly redeveloped over the LLCC. This development proved to be temporary, however, and Kyle became elongated northeast-southwest, subsequently splitting into two LLCCs. The northeastern centre moved away rapidly to the east-northeast and soon merged with a cold front while the southwestern LLCC, which remained classified as Kyle, remained stationary. At 30/2100 UTC the system was downgraded to a 30-kt tropical depression. (NOTE: Due to the difficulty in positioning the poorly- defined LLCC of Kyle, there are uncertainties in its track and motion at this time.) Tropical Depression Kyle was undergoing northerly shear on 1 October which was displacing the deep convection to the southern portion of the system. However, visible images, a QuikScat pass, and Dvorak estimates suggested a stronger system than a depression, and at 01/1500 UTC Kyle was upgraded back to a 35-kt tropical storm, centred about 300 nm south- southwest of Bermuda. Despite the shear Kyle's large circulation (albeit slanted) was able to continuously produce deep convection and the MSW was raised to 40 kts on the next advisory at 01/2100 UTC. Kyle continued to strengthen and became vertically-aligned again, reaching a secondary peak intensity of 60 kts at 02/2100 UTC while creeping a little (or reforming) to the east. For several days Kyle had been meandering around 27-29N, 64-66W, on the southern flank of a HIGH to its north. Another HIGH building over southern Georgia meant a change to a north- westerly heading late on 3 October. This HIGH introduced another episode of northeasterly shearing conditions for Kyle to endure, and by 04/0900 UTC the MSW was hovering at 35 kts. The LLCC had become partially- exposed to the northeast of the deep convection, and by 05/0300 UTC it had become completely detached 130 nm away from the deep convection. Kyle was downgraded to a depression at 05/0900 UTC with little associated deep convection and a poorly-defined LLCC, located approximately 350 nm west of Bermuda. A slow crawl to the north-northeast began late on 5 October, and this had changed to an east-northeasterly motion by 06/0300 UTC. However, Kyle soon came to a halt again as it got stuck in a col with a ridge to the northeast and southwest, a large upper-level LOW to the east- southeast, and a broad frontal trough to the northwest over the east- central US. Meanwhile, Kyle was upgraded to tropical storm status for the third time at 1500 UTC on 6 October when located roughly 250 nm west-northwest of Bermuda. This upgrade was based on Dvorak classi- fications and several uncontaminated 35-kt wind speed vectors over the southern semicircle from a QuikScat pass. A deep convective bursting pattern occurred also on 6 October. The approaching upper-level LOW from the east-southeast began to influence Kyle early on 7 October and a slow south to southwestward motion began. The circulation became elongated west-northwest to east-southeast with one circulation centre near 33.5N, 71.5W, and a second vortex/vortmax around 32N, 70W, near the main convection. The centre was relocated to near 32.8N, 70.7W, which was a mean position between the two vorticity centres. Although the main convection was nearer the eastern centre, some small bursts had occurred near the western one. On 8 October the synoptic situation became more complicated. In addition to the large upper-level cold LOW to the southeast, there was a small mid-to upper-level LOW just east of Florida and a short-wave trough moving through the Carolinas. However, this pattern simplified as the cold LOW turned northward and weakened and the LOW near Florida moved southwards. The short-wave trough moved away to the northeast with an anticyclone following in its wake. Again, Kyle found itself moving on a curving southwesterly track around the southern flank of a HIGH. Late on 8 October Kyle consisted of basically a low-level cloud-swirl with very little convection. This led to its subsequent downgrade to a tropical depression at 08/2100 UTC, located about 425 nm east-southeast of Charleston, South Carolina. Subsidence associated with the HIGH was the prime culprit in suppressing associated deep convection, and Kyle continued as a swirl of low clouds through 9 October. A US Air Force Reserves reconnaissance mission investigating the system later that day found a MSW of only 25 kts. Kyle turned more to the west and began to look a little healthier early on 10 October as convection developed, first in the southeast and east quadrants, and then over the LLCC. However, northerly shearing quickly blew this convection into the southern portions of the storm. Early on 11 October deep convection increased markedly and the Jacksonville radar showed improved banding features. An Air Force Reserves' aircraft flew into the system around 0700 UTC on 11 October and found 45-kt flight-level winds about 40 nm northeast of the centre along with a central pressure of 1008 mb. Kyle was upgraded to a tropical storm once again with a MSW of 35 kts at 0900 UTC, centred approximately 100 nm south-southwest of Charleston. The storm began to accelerate toward the north-northeast parallel to the Carolina coastline ahead of a mid-level trough and associated cold front. Only the western part of Kyle's circulation moved overland, and a reconnaissance plane indicated that most of the tropical-storm force winds were occurring to the east of the LLCC over water. A later flight into the storm around 11/2100 UTC found a maximum flight-level wind of only 29 kts, so Kyle was downgraded to a depression in a special advisory issued at 12/0000 UTC when the centre was located very near Cape Fear, North Carolina. Tropical Depression Kyle moved through the Outer Banks during the night and emerged into the Atlantic very early on 12 October. A reconnaissance mission at 12/0600 UTC found winds of 49 kts at 450 m along with a pressure of 1009 mb over eastern Pamlico Sound. Also, the Diamond Shoals C-MAN station reported 8-min avg winds of 38 kts with gusts to 43 kts at 0700 UTC. Based on these observations, Kyle was upgraded back to tropical storm intensity for the fifth time at 12/0900 UTC. The storm was located about 50 nm northeast of Cape Hatteras, and had accelerated east-northeastward at 20 kts as it interacted with a mid to upper-level shortwave trough. The final advisory--the 89th--was issued by NHC at 12/1500 UTC when the wind-field of Kyle began to expand and its associated convection took on the appearance of a frontal band. The extratropical Kyle was tracked across the Atlantic, executing its third anticyclonic loop on 14 October, then heading east-southeastward and southeastward. On the 17th Kyle's remnants turned east-northeastward and passed just north of the Azores Island of Faial. The island reported 30-kt winds and dew points of 20 C as the LOW approached. There was a notable wind shift associated with this system, signifying the presence of fronts. Kyle finally ended its long, long trek on 18 October as it was absorbed into an extratropical LOW centred to its northwest. The merger of this LOW with the remnants of Kyle resulted in a large, deep LOW which moved northeastward to affect the British Isles during 20-23 October. C. Meteorological Observations ------------------------------ On 30 September Bermuda experienced wind gusts to tropical storm force. This was caused by the combination of the outer part of Kyle's circulation and a cold front. The only significant weather report due to Kyle in the US was from the Diamond Shoals C-MAN station which reported 8-min avg winds of 38 kts with gusts to 43 kts at 12/0700 UTC. D. Damage and Casualties ------------------------ The deep depression associated with the remnants of Kyle caused one death in stormy seas southwest of the British Isles. There were no other reports of casualties or damage as Kyle remained over the open waters of the Atlantic. (Report written by Kevin Boyle) HURRICANE LILI (TC-13) 21 September - 4 October -------------------------------------------- A. Storm Origins ---------------- The humble beginnings of Hurricane Lili were first mentioned in a STWO issued at 1530 UTC on 20 September. An area of cloudiness and showers associated with a westward-moving tropical wave was located about 1400 nm east of the Windward Islands. This wave had likely left the African coast around the 16th or 17th. Upper-level conditions were forecast to be favourable for development, and STWOs issued during the 20th and 21st September indicated that the disturbance was becoming better organized. Ship reports and buoy data showed a broad LLCC, and at 2100 UTC, 21 September, the first advisory was issued on Tropical Depression Thirteen, located near 10.4N, 45.7W, or about 825 nm east- southeast of Barbados. The initial MSW on this advisory was 30 kts. For the following two to three days, the depression was forecast to move on a predominantly westward track, steered by a mid-level ridge to the north. The MSW remained at the 30-kt threshold through the 22nd as the storm moved smartly westward toward the Windward Islands. Despite the impres- sive convective cloud pattern, visible satellite images revealed that the LLCC was displaced west of the CDO. This was confirmed by a 21/1728 UTC TRMM pass. At 23/1200 UTC the centre was positioned near 12.7N, 58.7W, or about 50 nm east-southeast of Barbados, moving westward at 20 kts. Surface observations at 23/1500 UTC suggested that the LLCC was elongated west to east, and advisory positions at this time were a full degree or more west of the satellite fixes. The 23/1500 UTC advisory also noted that Barbados had reported winds of 36 kts, gusting to 48 kts, during a light shower. These winds were possibly caused by downdrafts bringing the 40-kt gradient-level winds down to the surface. An Air Force Hurricane Hunter plane investigating the system found 58-kt winds at 300 m, equivalent to a surface MSW of 45 kts. Based on this finding, Tropical Depression Thirteen was upgraded to Tropical Storm Lili in a special advisory at 23/1530 UTC. The centre was located about 40 nm south-southwest of Barbados, moving slightly north of due west at 17 kts. B. Track and Intensity History ------------------------------ The MSW was increased to 50 kts at 23/2100 UTC based on an aircraft report of 64 kts at 450 m at 1712 UTC. Satellite images and surface observations at this time indicated that Tropical Storm Lili was continuing to become better organized and that deep convection was beginning to wrap around the north side of the circulation. Lili had begun crossing the Windward Islands, and at 24/0000 UTC was located near 12.7N, 62.0W, or about 40 nm west of the Grenadine Islands. Wind gusts to 65 kts and 47 kts had been reported from Barbados and St Lucia, respectively. At 24/1500 UTC the MSW was increased to 60 kts based on an aircraft report of 244-m flight-level winds of 76 kts in the northeast quadrant. The westerly heading had slowed to 9 kts by 25/0300 UTC with Lili having weakened dramatically to a minimal tropical storm with a MSW of 35 kts. This weakening was due to southerly shearing conditions over the system. In fact, an Air Force reconnaissance flight during the early evening was unable to find a closed LLCC. Radar data from San Juan indicated the possible presence of a circulation near 15.7N, 65.5W, but the plane could only find easterly winds of 35-45 kts at flight-level and easterly surface winds of 37 kts in that area. This suggested that the circulation was at mid to upper-levels only. A reconnaissance flight around 25/1200 UTC indicated the presence of at least a weak LLCC near 13.7N, 68.7W, but not defined enough for a vortex message. Flight-level (450 m) winds of 47 kts and 45 kts were found to the northeast of the centre, respectively. Based on these wind reports, the MSW was increased to 40 kts in an intermediate advisory at 1200 UTC. Due to the uncertainty of the centre position, the LLCC was relocated a little to the south to near 14.1N, 69.3W, or about 260 nm south-southeast of Santo Domingo at 25/1500 UTC. The MSW was reduced back to 35 kts at 26/0300 UTC. Lili appeared very ragged in infrared satellite images at this time, and most of the deep convection was located northeast of the weak and broad LLCC. An Air Force Hurricane Hunters' plane reported that the strongest winds in the northern semi- circle were well away from the centre. The deep convection had decreased in areal coverage, and since reconnaissance flights had struggled to find a LLCC for almost 48 hours, Lili was downgraded to a tropical wave and advisories discontinued at 26/1500 UTC. Due to the likelihood of regeneration NHC continued to monitor Lili's remnant LOW. At 2130 UTC the system was located about 200 nm southeast of Jamaica, and conditions were expected to become more favourable for development during the following two days. A Special Tropical Disturbance Statement (STDS) was issued at 27/0235 UTC indicating that deep convection was reforming near the LLCC and that the system was getting better organized with a well-defined LLCC. The STDS also noted that advisories would resume at 27/0300 UTC. Lili was restarted as a tropical depression with a MSW of 30 kts at this time, located about 205 nm southeast of the eastern tip of Jamaica. A 26/2309 UTC micro- wave pass indicated that the tight LLCC was located just southwest of the deep convection, indicating that some wind shear was still present. Cloud top temperatures had cooled to -80 to -85 C over the previous few hours. Although shear was still affecting the system, Lili regained tropical storm status at 27/1500 UTC with the MSW increasing to 40 kts six hours later. At 27/2100 UTC the LLCC began to be "smothered" by the CDO generated by the deep convection as the shear conditions lessened. Lili was moving toward the northwest at 7 kts early on the 28th, but had slowed to 3 kts by 28/2100 UTC with the storm centred roughly midway between the eastern tip of Jamaica and the western tip of Haiti. An Air Force Reserves' reconnaissance plane found flight-level westerly winds of 51 kts south of the centre along with a minimum central pressure of 999 mb at 28/0900 UTC. The centre was relocated to near 18.6N, 75.8W, or about 100 nm south-southwest of Guantanamo Bay, Cuba, at 2100 UTC after aircraft reported that the centre had reformed to the northeast of the previous one. The MSW had been upped slightly to 45 kts at 28/0000 UTC, but was reduced back to 40 kts at 29/0300 UTC based on a CP of 1002 mb and peak 850-mb flight-level winds of 50 kts in the northeast quadrant. However, the reconnaissance mission around 29/1200 UTC found peak 850-mb winds of 57 kts with a CP of 994 mb, so the MSW was raised once more to 45 kts at 29/1500 UTC, and to 50 kts six hours later. The reconnaissance crew also noted the presence of an 8-11 nm diameter eye feature which persisted through the 29th. At 2100 UTC on 29 September the centre of Tropical Storm Lili was moving westward at 4 kts just north of western Jamaica near 18.7N, 77.8W, or only about 20 nm north- northeast of Montego Bay. The cyclone gradually began to pull away from Jamaica to the west- northwest and steadily intensified. The MSW was upped to 55 kts at 30/0300 UTC--an earlier GPS dropsonde just northeast of the centre had revealed average boundary layer winds of 70 kts, and the aircraft had reported the existence of a closed eye wall 20 nm in diameter. Lili finally reached hurricane intensity at 1500 UTC on 30 September when located just north of Little Cayman Island. The discussion bulletin well illustrates the manner in which the forecasters have to digest and draw conclusions from the data they receive: "Although flight- level winds do not quite support hurricane intensity, as the peak 850-mb wind reported by the reconnaissance aircraft was 75 kts--of which 80% is 60 kts--a GPS dropsonde in the northeast eyewall supports upgrading Lili to a hurricane. This drop had 81 kts at 14 m elevation, and a low-layer mean wind of 90 kts, which adjusts to 73 kts at the surface. The advisory intensity is set to 65 kts, and is a compromise between the adjusted values from the aircraft and dropsonde." Hurricane Lili began to draw a bead on western Cuba as its forward motion slowly increased. The storm's west-northwestward track was caused by a deep-layer high centred near 30N, 80W, and this feature was forecast to steer Lili in the same direction for several more days. The storm continued to strengthen and peak winds were up to 75 kts and the CP had fallen to 975 mb by the time the centre reached the Isle of Youth south of western Cuba during the early morning of 1 October. Lili's eye was crossing the western tip of Cuba around 1800 UTC. The storm was upgraded to a Category 2 hurricane with 85-kt winds at this time, based on reconnaissance reports, even though the storm "sputtered" a bit due to land interaction (part of the eyewall weakened and cloud tops warmed some). By 2100 UTC Lili's eye had cleared Cuba and entered the southeastern Gulf of Mexico, being located about 45 nm north of Cabo San Antonio, Cuba, and moving northwestward at 13 kts. Satellite images at this time indicated a healthy, organized system with a well-defined eye seen on radars at Casablanca, Cuba, and Key West, Florida. The MSW was increased to 90 kts at 2100 UTC based on CI estimates of 90 kts from TAFB, SAB and AFWA, plus earlier flight-level winds of 102 kts reported by a reconnaissance aircraft northeast of the centre while Lili's eye was still over Cuba. Once Lili had entered the Gulf of Mexico, the storm steadily strengthened as it tracked northwestward at 14 kts. During the after- noon and evening of 1 October Lili went through an eyewall replacement cycle as the eye diameter shrank from 35 nm to 17 nm. The 90-kt MSW was maintained for the 02/0300 UTC advisory, although the discussion noted that the eye had cleared out and became better defined with the eye temperature rising from -55 C to -9 C in just two hours. The CP had fallen to 955 mb by 02/0600 UTC and the MSW was increased to 95 kts, putting Lili on the brink of major hurricane status. The hurricane was then centred a little over 400 nm south-southeast of New Orleans. A reconnaissance plane around 1200 UTC found 125-kt flight-level winds 10 nm northeast of the centre along with a CP of 953 mb. On this basis Lili's MSW was upped to 105 kts at 1500 UTC, making the storm a Category 3 hurricane on the Saffir/Simpson scale as it continued moving at 13 kts toward the Louisiana coast. An aircraft around 1700 UTC reported that the central pressure had fallen from 954 mb to 941 mb in five hours. A peak flight-level wind of 131 kts was also measured; hence, a special advisory package was issued at 1800 UTC upgrading Lili to a Category 4 hurricane with 115-kt winds. The storm's centre was then located about 285 nm almost due south of New Orleans. The CP continued to fall, but more slowly, reaching a minimum of 938 mb at 02/2000 UTC. The MSW was increased to 120 kts at 2100 UTC based on a flight-level wind of 136 kts. Lili's peak intensity of 125 kts occurred around 03/0300 UTC when the storm was centred about 190 nm south-southeast of Marsh Island on the Louisiana coast. Even though the CP had risen to 942 mb, a peak 700-mb wind of 141 kts was observed by an Air Force Reserves' reconnaissance plane, and the stepped-frequency microwave radiometer on the NOAA research plane indicated surface winds of 125 kts. Lili maintained its 125-kt peak intensity for only a short while before a rapid weakening trend set in. By 03/0900 UTC the MSW had fallen to 105 kts, the eyewall had collapsed into fragments, and water vapour imagery suggested that the system was being sheared from the southwest. Radar images at this time indicated possible dry air intrusion into the southwestern part of the circulation. Rapid weakening continued and the MSW had fallen to 85 kts when Lili's eye made landfall near the western edge of Vermillion Bay around 03/1400 UTC. At the time of landfall Lili was moving due northward, and by 03/2100 UTC the weakening cyclone was moving northward at 16 kts and had weakened to a 45-kt tropical storm located very near Alexandria, Louisiana. Turning northeastward, Lili was downgraded to a tropical depression at 04/0900 UTC when centred near 34.3N, 90.9W, or 120 km southwest of Memphis, Tennessee, moving north-northeastward at 18 kts. HPC issued only two storm summaries on the remnants of Lili, the second at 2100 UTC stating that no closed circulation had been evident since 1800 UTC and that the remnants of the storm were being absorbed into a low-pressure system in the northern Great Lakes area. C. Meteorological Observations ------------------------------ Lili reached its peak intensity of 125 kts with a CP of 938 mb during the afternoon of 2 October in the north-central Gulf of Mexico. By this time the storm had grown into a fairly sizable hurricane. Sustained winds of hurricane force extended outward from the eye about 45 nm in the northeast quadrant and 20 nm to the southwest. Gales reached out 170 nm to the northeast and about 100 nm in the southwest quadrant. Early in its career as Lili was passing through the southern Wind- wards, Barbados recorded a peak sustained wind of 41 kts, gusting to 65 kts, while St. Lucia reported peak gusts of 43 kts. On the morning of 30 September, Little Cayman reported peak gusts in the 61-70 kt range. Punta del Este on the Isle of Youth measured gusts to 94 kts around 1200 UTC on 1 October, while La Fe reported sustained winds of 55 kts. Shortly before 2100 UTC on 2 October, the centre of Lili passed only about 10 nm from NOAA buoy 42001 (25.9N, 89.7W). The pressure fell 44 mb in three hours to a minimum of 956 mb. The buoy's anemometer recorded an 8-min avg sustained wind of 91 kts with a peak gust of 129 kts, accompanied by 10-m seas. As Lili's centre was nearing the Louisiana coast (around 03/0900 UTC), Grand Isle and Southwest Pass reported winds gusting to 69 kts and 70 kts, respectively. Storm chaser Tim Marshall was situated near Delcambre, Louisiana, on Route 14. Tim's instrumentation recorded the maximum winds at 1508 UCT: a sustained wind of 54 kts with a peak gust of 84 kts. The minimum SLP of 977.6 mb was measured six minutes later. NOTE: Some reconnaissance reports were included in the narrative above. Additional information reported by the reconnaissance flights can be found in the discussion bulletins issued with each regular advisory. These are archived on NHC's website at the following URL: < http://www.nhc.noaa.gov/archive/2002/index.shtml > Lili's circulation was not nearly as large as that of Isidore, and the storm moved through fairly quickly; hence, rainfall accumulations were significantly less than with the earlier cyclone. A power plant near Alexandria, Louisiana, recorded 126 mm during the 24 hours ending at 04/1200 UTC, and a station in Franklinton, Louisiana, measured 119 mm during the same period. The highest storm total rainfall amounts reported in the HPC storm summaries were (all sites in Louisiana): Buras 213 mm Boothville 183 mm Slidell 164 mm D. Damage and Casualties ------------------------ As Lili passed through the Windward Islands, heavy rains triggered mudslides with left four persons dead on the island of St. Vincent. There were also four flood-related deaths in Jamaica where severe flooding destroyed about 30% of the island nation's sugarcane crop. Ham radio reports from Cayman Brac indicated that some damage occurred there in the form of downed trees, power lines and poles. Also, several homes experienced roof damage and there was some minor beach erosion. In Cuba 190,000 persons were evacuated in advance of the second hurricane to affect the western provinces in less than two weeks. One report stated that 600,000 persons were evacuated, but that could have been the total from both Lili and Isidore. Lili followed so closely on the heels of Isidore on an almost identical track that it is difficult, if not impossible, to accurately assess the damage caused by each hurricane. Over 50,000 homes were significantly damaged by both hurricanes--32,000 with structural damage and 18,000 with damaged roofs. The two storms caused extensive damage to coffee and banana plantations, and the rice harvest was severely impacted. Also, high winds from the hurricanes downed power lines and poles, leading to a loss of electricity in many rural and coastal towns. Total damage in the United States has been tentatively estimated at $800 million. The Louisiana sugarcane crop was especially hard hit. A report from the United Nations Environment Programme (UNEP) stated that the total damage estimate from Lili was $2 billion (presumably in USD). Storm chaser Mike Theiss from Key Largo, Florida, has placed on his website quite a few pictures depicting flooding and other damage from Louisiana. The address is: < http://www.mthurricane.com > Many additional articles, reports, and press releases on the effects of Hurricane Lili may be found on the ReliefWeb homepage at the following URL: E. A Bullet Dodged ------------------ Regarding Lili's dramatic weakening in the hours before landfall in Louisiana, many media reports, in describing the storm, used the old cliche that the U. S. really "dodged a bullet". Louisiana was very fortunate indeed that Lili weakened before marching ashore. Given that the force of the wind varies with the square of the velocity, 125-kt winds would have had over twice the force of winds of 85 kts, not to mention the additional destruction that a much higher storm surge would have caused. No doubt many research papers will be written investigating the factors that led to Lili's rapid intensification and equally rapid demise. Just to speculate a little--it may well be that the U. S. dodged two bullets. Had Isidore not made the sudden turn southward into the Yucatan Peninsula and subsequently weakened, it would have eventually moved into the very warm waters of the Bay of Campeche and away from the influence of the landmass to its south. Some of the models were forecasting Isidore to become a Category 4 hurricane, and had this happened, a large severe hurricane akin to Hurricane Carla (1961) could have borne down on the Texas or western Louisiana coastline. And to continue the speculation a bit further, had the scenario with Isidore described above panned out, its stirring of Gulf waters farther east likely would have been less, meaning that Lili would have had better thermodynamics to accompany its excellent dynamics, which in turn would mean that the storm very possibly could have made landfall as a significantly stronger hurricane. And if Lili had bent a little farther east, New Orleans or perhaps Biloxi, Mobile, or Pensacola could have had to deal with a Category 3 or 4 hurricane. Just as Hispaniola's high mountains have saved the U. S. from many destructive hurricanes, so Mexico's Yucatan Peninsula in this case helped to prevent at least one, possibly two, intense hurricanes from striking the United States. (Report written by Kevin Boyle and Gary Padgett) ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for September: 1 tropical depression 2 tropical storms Sources of Information ---------------------- Most of the information presented below was obtained from the various tropical cyclone products issued by the Tropical Prediction Center/National Hurricane Center (TPC/NHC) in Miami, Florida (or the Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii, for locations west of longitude 140W): discussions, public advisories, forecast/advisories, tropical weather outlooks, special tropical disturbance statements, etc. Some additional information may have been gleaned from the monthly summaries prepared by the hurricane specialists and available on TPC/NHC's website. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. The following summaries for the three September systems were authored by John Wallace of San Antonio, Texas. A special thanks to John for his assistance. Northeast Pacific Tropical Activity for September ------------------------------------------------- In contrast to an active August, the month of September was unusually quiet across the Northeast Pacific basin. Only two tropical storms formed, and neither reached hurricane intensity, making this the first time since 1972 that no hurricanes formed during the month of September. The averages for the entire NEP basin over the period 1971-2001 are 3.6 tropical storms/hurricanes, 2.2 hurricanes, and 1.1 intense hurricanes. On the first day of the month, Hurricane Hernan, which had formed in late August, became the second Category 5 hurricane of the season while located about 350 nm south-southwest of Cabo San Lucas. Hernan continued to move away from the coast and had dissipated far to the west of the Baja by the 6th. Also, on the 1st, former Hurricane Fausto, which had weakened into a tropical depression, briefly regained tropical intensity in the central Pacific well to the northwest of Hawaii. (Fausto was not re-upgraded operationally, but the end-of-season summary from TPC/NHC stated that it regained tropical storm intensity.) The complete reports on Hernan and Fausto can be found in the August summary. Early in the month Tropical Depression 11E moved closely enough to the Mexican coast that tropical storm warnings were hoisted for the southwestern Baja California Peninsula, but the system neither affected the coast nor reached tropical storm intensity. Around mid-month Tropical Storm Iselle cranked up into a 60-kt tropical storm while located south of the Baja Peninsula, but did not affect the Mexican coast. Short-lived Tropical Storm Julio on 26 September became the first NEP cyclone of the year to make landfall in Mexico, moving inland near Zihuatanejo. Julio's rains brought some significant flooding to the region. TROPICAL DEPRESSION (TC-11E) 5 - 8 September --------------------------------------- The disturbance that become Tropical Depression Eleven-E was first noted in the NEP on 31 August. The system tracked westward and slowly organized as it trailed powerful Hurricane Hernan--by 5 September it had become organized enough to warrant upgrading to Tropical Depression Eleven-E at 2100 UTC, located roughly 175 nm west of Manzanillo, Mexico. The depression's northwesterly track around the periphery of a subtropical ridge to its north threatened to take it close to Baja California. Weighed with uncertainty in the intensity forecast, the Mexican government issued a tropical storm watch for the coast north of Cabo San Lucas to Cabo San Lazaro on the west coast of the Baja Peninsula which was later upgraded to a tropical storm warning and hurricane watch. Eleven-E flirted with tropical storm strength on the 6th; its official peak MSW was 30 kts, with a minimum CP of 1006 mb at 0900 UTC on the 7th when centered about 115 nm southwest of Cabo San Lucas. The system then began a weakening trend due to dry air entrainment, though its CP oddly reached 1006 mb again on the 8th during a brief burst of convection. Dissipation was rapid, and the final advisory was issued at 1500 UTC on 8 September with the weakening center about 225 nm west-southwest of Cabo San Lucas. The remnant LOW was no longer evident by the 11th. No casualties or other damages are known to have resulted from Tropical Depression Eleven-E. (Report written by John Wallace) TROPICAL STORM ISELLE (TC-12E) 15 - 20 September ----------------------------------------- The disturbance that became Iselle developed suddenly on 14 September as a large cyclonic disturbance south of Acapulco, Mexico. By 0900 UTC on the 15th, satellite data and a report of a 1008-mb SLP from ship WTEE at 0100 UTC warranted its upgrade to Tropical Depression Twelve-E. The depression, located approximately 250 nm south of Manzanillo, initially tracked west-northwestward, roughly paralleling the coast. The depression organized steadily, and at 0000 UTC on 16 September became Tropical Storm Iselle, centered about 190 nm south-southwest of Manzanillo, Mexico. The upgrade was based largely on surface observations and a ship report. Concurrent with its upgrade, a tropical storm warning was issued for the coast from Lazaro Cardenas to Puerto Vallarta. Easterly shear kept the intensification rate slow for the next two days, while a decreased threat prompted the Mexican government to drop the warnings for the coast after 1500 UTC on the 16th. Iselle's MSW peaked at 60 kts at 2100 UTC on 17 September, with a CP of 990 mb, when it was located roughly 250 nm west-southwest of Cabo San Lucas. Dry air entrainment weakened Iselle thereafter, and its forward speed decreased as the ridge to the north weakened due to an approaching trough. Iselle was already well on the way out by the 18th, but a renewed burst of convection early on the 19th enabled Iselle to "feel" the mid to upper-level trough that had previously left it in a weak steering flow. The storm turned abruptly northeastward toward the Baja coast in response, though its forward speed remained little more than a drift. Shear added to the overall hostility of the synoptic environment, and Iselle was downgraded to a depression at 2100 UTC on the 19th. This development was interesting, because a ship report of a sustained wind as high as 43 kts was discounted based on the weight of satellite data and two other ship reports. Iselle made an eleventh-hour north-northwestward turn away from the coast under the influence of an upper-level LOW to its west. Weakening continued, and the final advisory on Tropical Depression Iselle was issued at 1500 UTC on 20 September when the dying circulation was located approximately 200 nm west-northwest of Cabo San Lucas. A cyclonic remnant was no longer identifiable the following day. No casualties or damages are known to have resulted from Tropical Storm Iselle. (Report written by John Wallace) TROPICAL STORM JULIO (TC-13E) 25 - 26 September ---------------------------------------- The progenitor disturbance for Julio was first definitively noted on 24 September; it may have been extant earlier, but was disrupted by the large circulation of Hurricane Isidore to the northeast. The system organized quickly beginning at 0600 UTC on the 25th, and was subsequently upgraded to Tropical Depression Thirteen-E at 1500 UTC, located roughly 90 nm south-southwest of Zihuatanejo, Mexico. An upper-level LOW southwest of Baja California steered Julio slowly northward, presenting an immediate threat to the coast. A tropical storm warning was issued with the first advisory, extending from Zihuatanejo to Punto San Telmo. Though it was under some easterly shear, the depression strengthened to Tropical Storm Julio at 2100 UTC when it was located some 30 nm west of Zihuatanejo. Proximity to land and shear kept Julio a minimal tropical storm with a MSW of 35 kts and associated CP of 1000 mb. This was Julio's peak intensity. (Editor's Note: The NHC discussion for the 26/0300 UTC advisory noted that based on Dvorak intensity estimates of 45 kts from TAFB and SAB, plus an earlier 35-kt report from Zihuatanejo, the synoptic intensity at 0000 UTC had been raised to 40 kts, but as the storm's center had made landfall, the 0300 UTC advisory intensity was brought back down to 35 kts. The end-of-season report on TPC/NHC's website lists the peak MSW for Julio at 40 kts.) Julio made landfall just west of Lazaro Cardenas, Mexico, near 0300 UTC on 26 September. The cyclone made an expected northwestward turn once inland, as the upper LOW to its west moved away, and a new ridge built in over Mexico. On its new track Julio roughly straddled the coast, in a fashion similar to that of Hurricane Pauline in 1997. Julio was no Pauline, of course, and the rugged terrain of the Mexican coast had weakened it to a depression by 0900 UTC on the 26th. The final advisory was issued at 1800 UTC that same day as a closed circulation was no longer evident. There are conflicting reports of damage from Julio. The NHC lists no significant damages or casualties. An unofficial source, however, states that damage in Zihuatanejo was substantial: 500 houses were damaged and 1,000 trees uprooted, in addition to disruption of the power grid (1). A more reliable source states that flash flooding from Julio damaged or destroyed 100 homes in Acapulco and Zihuatanejo (2). No deaths were reported in either source. (Editor's Note: A brief mention was made of Julio in a release archived on the ReliefWeb homepage which stated that 5000 persons were affected by the heavy rains and flooding in Guerrero State.) References ---------- (1) (2) (Report written by John Wallace) ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for September: 1 tropical depression ** 3 tropical storms ++ 1 super typhoon ** - classified as a tropical depression by JMA only ++ - one of these was classified as a tropical storm by JMA and NMCC but not by JTWC Sources of Information ---------------------- Most of the information presented below is based upon tropical cyclone warnings and significant tropical weather outlooks issued by the Joint Typhoon Warning Center of the U. S. Air Force and Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion tropical cyclone tracks file, I normally annotate track coordinates from some of the various Asian warning centers when their center positions differ from JTWC's by usually 40-50 nm or more. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. Michael V. Padua of Naga City in the Philippines, owner of the Typhoon 2000 website, normally sends me cyclone tracks based upon warnings issued by the Japanese Meteorological Agency (JMA) and the Philippines' Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). Also, Huang Chunliang of Fuzhou City, China, sends me each month tracks obtained from warnings issued by the National Meteorological Center of China (NMCC), the Central Weather Bureau of Taiwan (CWBT) and the Hong Kong Observatory (HKO). A very special thanks to Michael and Chunliang for the assistance they so reliably provide. In the title line for each storm I have referenced all the cyclone names/numbers I have available: JTWC's depression number, the JMA-assigned name (if any), JMA's tropical storm numeric designator, and PAGASA's name for systems forming in or passing through their area of warning responsibility. The summaries for Tropical Storms Hagupit and Mekkhala were written by Kevin Boyle of Stoke-on-Trent, UK, and with significant contributions by Huang Chunliang of Fuzhou City, Fujian Province, China (currently a student in Beijing). A special thanks to Kevin and Chunliang for their assistance. Northwest Pacific Tropical Activity for September ------------------------------------------------- As the month of September opened, the remnants of the destructive Typhoon Rusa were weakening over the Korean Peninsula and the Sea of Japan. Far to the south and east, powerful Typhoon Sinlaku was taking aim on the island of Okinawa, the eye crossing directly over the island on the 4th and 5th. Late on the 7th a somewhat weaker Sinlaku made landfall on the Chinese mainland near Wenzhou City. Typhoon Sinlaku was rather destructive with losses estimated at upwards of 4 billion yuan. Sinlaku was also deadly as 32 persons lost their lives due to the storm. Much farther to the east, intense Typhoon Ele had entered the Northwest Pacific basin from the Central North Pacific, crossing the International Dateline around 0000 UTC on 30 August. Ele moved generally on a slow northward track for several days as it gradually weakened, becoming a tropical depression near the 40th parallel late on 9 September. Typhoon Ele's entire track remained east of 165E. Complete reports on Rusa, Sinlaku, and Ele can be found in the August summary (with Ele's report in the Northeast Pacific basin portion of the summary). Tropical cyclogenesis waned in the Northwest Pacific basin during September after a very active July and August. Three tropical storms formed (one of these not recognized as a tropical cyclone by JTWC) plus the year's seventh super typhoon (per JTWC nomenclature). The active pattern in the South China Sea seen during August continued into September with two tropical storms forming and making landfall in southern China. Tropical Storm Hagupit formed between Luzon and Hong Kong during the second week of the month and moved westward, making landfall in Guangdong Province southwest of Hong Kong on the 12th. The weak remnants of Hagupit drifted around in the northern South China Sea/southern China area for nearly a week following the cyclone's land- fall. A couple of weeks later, Tropical Storm Mekkhala formed south of Hainan Dao and moved northward across the island and into the Gulf of Tonkin. Mekkhala reached the Chinese coast in the Guangxi Autonomous Region but retreated back out into the Gulf of Tonkin where it eventually dissipated. In between Hagupit and Mekkhala, a tropical depression moved northward toward Japan from the Marianas Islands. South of Honshu the system intensified and was named Tropical Storm Changmi by JMA. NMCC also issued tropical storm warnings on the system. JTWC, however, did not regard Changmi as a tropical cyclone and did not issue warnings. The system probably was some sort of baroclinic/hybrid development. The final named storm of the month formed on the 27th east of the Marianas and ultimately developed into a super typhoon. The storm, Higos, passed through the northern Marianas and as it began to weaken, got caught in a strong southerly steering current and raced northward toward Japan, passing over or very near Tokyo at full typhoon intensity. A tropical disturbance north of Palau was increasing in organization on 13 September and elicited a TCFA from JTWC, but this was cancelled early on the 14th after the convection dissipated. Another disturbance was classified as a weak tropical depression by JMA in the Summary portion of their High Seas bulletins (implying 25-kt winds). The system was located approximately 625 nm east-northeast of the northernmost Marianas Islands around 1800 UTC on 21 September and moved generally northward. The final bulletin referencing this system as a tropical depression was issued at 22/1800 UTC and placed the center about 725 nm east-northeast of Iwo Jima. An interim STWO from JTWC at 0200 UTC on the 22nd assigned this disturbance a fair potential for development as satellite imagery showed a partially-exposed LLCC with a small but persistent area of deep convection over the western portion of the LLCC. However, only a few hours later (at 0900 UTC) another STWO was issued downgrading the development potential to poor. Satellite imagery depicted an exposed LLCC with minimal deep convection being sheared to the west of the LLCC. (A track for this system was included in the September cyclone tracks file based on JMA's bulletins.) TROPICAL STORM HAGUPIT (TC-23W / STS 0218) 9 - 17 September ------------------------------------------ Hagupit: contributed by the Philippines, means to 'lash' or 'flog' A. Storm Origins ---------------- At 0600 UTC, 8 September, JTWC issued a STWO for an area of convection located near 19.4N, 126.4E, or approximately 240 nm east-northeast of Luzon, that had developed several hours earlier. This area of convection was the seedling that became Tropical Storm Hagupit. Animated multi- spectral imagery at this time indicated a broad LLCC with cycling deep convection. An analysis at 200 mb indicated that the area was under weak to moderate wind shear. The development potential was rated poor on this STWO, but the disturbance subsequently began to show signs of increased organization. A TCFA was issued at 09/1900 UTC and JTWC issued the first warning on Tropical Depression 23W at 10/0000 UTC, placing the center approximately 320 nm east-southeast of Hong Kong, or near 19.5N, 119.0E. JMA was also classifying the system as a tropical depression at this time, positioning the center near 19.0N, 118.0E at 10/0000 UTC. The system continued to consolidate and was upgraded to tropical storm status on the JTWC advisory at 10/1200 UTC. B. Track and Intensity History ------------------------------ The 10/1200 UTC warning relocated the LLCC about 100 nm northwest of the previous warning position so that the system was consolidated about 180 nm east-southeast of Hong Kong, or near 20.6N, 116.9E. Tropical Storm 23W continued on its westward track at around 10 kts, and was assigned the name Hagupit at 11/0000 UTC when JMA upgraded the system to 35 kts (10-min avg), fixing the centre near 20.4N, 114.1E. At this time Hagupit's outflow in the northern quadrants was being restricted by the upper-level ridge which was governing the movement of the cyclone. Tropical Storm Hagupit peaked at 11/0600 UTC with its MSW estimated at 45 kts, and then slowly began to weaken as it approached the Chinese coastline. (NOTE: Both HKO and NMCC considered Hagupit a much stronger system with a 10-min avg MSW of 60 kts at 11/0600 UTC and 11/1200 UTC, respectively. JMA also analyzed Hagupit as a more intense tropical cyclone than did JTWC with an estimated 10-min avg MSW of 50 kts.) Landfall occurred at 1930 UTC on 11 September approximately 110 nm west-southwest of Hong Kong. JTWC had by this time downgraded Severe Tropical Storm Hagupit to a depression. The system continued to weaken as it moved further inland and JTWC issued the final warning on Hagupit at 12/0600 UTC. HKO followed suit six hours later, but NMCC continued to issue bulletins through 13/0600 UTC. Shangchuan Dao, Guangdong Province, recorded sustained 10-min avg winds of 49 kts, gusting to 68 kts, in Hagupit. Pinggang Town, Yangjiang City, where Hagupit made landfall, reported winds of 58 kts during the storm's landfall. (It is uncertain if this is a sustained wind or a gust measurement.) The remnants of Tropical Storm Hagupit meandered and continued to plague the southern coastline of China for several days. The broad LLCC moved back into the South China Sea and attempted to reform. Conditions for redevelopment were good with excellent diffluence aloft aided by an upper-level LOW to the east and a passing trough poleward. There was very little wind shear over the area. JTWC issued a TCFA at 15/0100 UTC, upgrading the potential for development to good, but the development potential was downgraded to poor on the next STWO issued at 16/0600 UTC since the LLCC had lost its deep convection by this time. After another STWO was issued, the system was finally considered properly dissipated on the final STWO issued on Hagupit at 18/0030 UTC. (NOTE: JMA continued to issue bulletins on the remnant LOW throughout this period until 17/1800 UTC.) C. Meteorological Observations ------------------------------ The rainfall reports below were sent by Huang Chunliang of Fuzhou City, Fujian Province, China. A special thanks to Chunliang for compiling and sending the information. Most of the amounts tabulated are 24-hour totals, and I have included only those exceeding 100 mm. (1) Daily Rainfall Reports from the Meteorological Service of Guangdong (GRMC) 10/0000--11/0000 UTC: No amounts exceeding 100 mm 11/0000--12/0000 UTC: Cities Stations Rainfall (mm) ----------------------------------------------- Yangjiang Yangjiang 118.0 Jiangmen Taishan 107.1 Jiangmen Enping 117.4 Jiangmen Shangchuan 118.3 12/0000--13/0000 UTC: Cities Stations Rainfall (mm) ----------------------------------------------- Jiangmen Enping 160.0 Yunfu Xinxing 142.1 Shanwei Haifeng 119.1 13/0000--14/0000 UTC: Data missing 14/0000--15/0000 UTC: Data missing 15/0000--16/0000 UTC: Cities Stations Rainfall (mm) ----------------------------------------------- Foshan Shunde 118.1 Zhongshan Zhongshan 256.8 Jiangmen Heshan 174.1 Shanwei Shanwei 112.8 Shanwei Haifeng 107.9 16/0000--17/0000 UTC: Data missing 17/0000--18/0000 UTC: No amounts exceeding 100 mm (2) Storm Total Rainfall Reports from the Meteorological Service of Guangdong (GRMC) from 11/0000--18/0000 UTC (only amounts exceeding 200 mm are listed): Cities Stations Rainfall (mm) ---------- ---------- ------------- Zhanjiang Zhanjiang 344.0 Zhanjiang Suixi 332.5 Zhanjiang Lianjiang 314.2 Zhanjiang Wuchuan 247.7 Zhanjiang Leizhou 327.5 Zhanjiang Xuwen 291.6 Jiangmen Heshan 323.7 Jiangmen Kaiping 277.9 Jiangmen Xinhui 282.5 Jiangmen Enping 510.3 Jiangmen Taishan 351.9 Jiangmen Shangchuan 524.7 Huizhou Huiyang 240.1 Huizhou Huidong 244.4 Shenzhen Shenzhen 346.8 Shanwei Shanwei 279.3 Shanwei Haifeng 321.8 Foshan Shunde 257.2 Shantou Shantou 223.3 Shantou Chaoyang 200.4 Shantou Chenghai 214.8 Zhuhai Zhuhai 407.8 Zhuhai Doumen 423.3 Zhongshan Zhongshan 493.1 Yangjiang Yangjiang 567.5 Yangjiang Yangchun 322.8 Maoming Maoming 292.8 Maoming Gaozhou 249.2 Maoming Huazhou 272.0 Maoming Dianbai 312.5 Jieyang Jiexi 328.3 Jieyang Puning 299.7 Jieyang Huilai 222.3 Yunfu Yunfu 258.6 Yunfu Luoding 207.1 Yunfu Xinxing 318.0 (3) Miscellaneous Meteorological Observations (a) Guangdong Province (1) Shangchuan Dao reported sustained winds of 49 kts, gusting to 68 kts in the storm. (2) A automatic weather station in Pingsha Town, Zhuhai City reported the highest daily rainfall amount of 198.2 mm during the period from 11/0000 through 12/0000 UTC. (3) Pinggang Town, Yangjiang City, where Hagupit made landfall, reported winds of 58 kts when the landfall occurred. It is uncertain if this is a sustained wind or a gust measurement. (b) Yulin City, Guangxi Region 12/0000--16/0000 UTC: Stations Rainfall (mm) --------------------- ------------- Yulin(the urban area) 312 Luchuan 427 Beiliu 238 Bobai 134 Rongxian 114 (c) Hainan Province Qionghai and Haikou recorded rains of 62 mm and 51 mm, respectively, during the period from 18/0000 through 18/2100 UTC. (d) Jiangxi Province Suichuan, Jiangxi recorded rains of 156 mm during the 24-hour period ending at 14/1200 UTC. D. Damage and Casualties ------------------------ (1) Guangdong Province According to the statistics on the 17th of September, more than 866,700 people in 131 townships of six cities were affected, 330 houses destroyed and 43,880 hectares of crop lands flooded. The total economic loss caused by Hagupit was more than 270 million yuan (US$32.53 million). Also, eleven fishermen who were reported missing when Hagupit hit Guangdong were feared dead. This is the only casualties report that has been officially confirmed. (2) Guangxi Region The torrential rains in Yulin, Guangxi, triggered the most serious flooding in 30 years. (3) Jiangxi Province The death toll from flooding and landslides caused by torrential rains associated with Hagupit was placed at 25 in Suichuan County of Jiangxi Province, East China. Around 180,000 local people were affected by the disaster. During the 24 hours beginning at 0600 UTC on 13 September, rainfall amounts of 150-200 mm fell on the county. The water level of Suichuan River rose for a time to 99.24 meters, 0.24 meters above the warning line. A total of 159 villages were inundated, 110,000 hectares of farmland submerged, 400 water facilities destroyed, and 3800 houses and 180 bridges ruined. E. Fuzhou Rainfall Event ------------------------ It was somewhat unusual that Hagupit became a large-sized overland depression on the 12th. Looking back at the satellite images, one finds that the easternmost rainband extended as far as the southeast Chinese coast, though the western semicircle of the system was quite limited. A thunderstorm, which lasted from 2300 on the 12th through 0530 on the 13th Beijing Time (12/1500 - 12/2130 UTC), was considered the strongest one in Fuzhou in recent years. Station WMO 58847 (in Fuzhou City) recorded 124.9 mm of rains from the storm on the noisy night. In the urban area of Fuzhou, over 1000 hectares of farmland were inundated, resulting in economic losses of 30 million yuan. Luoyuan, the northernmost county of Fuzhou, was stricken by rare torrential rains. The county recorded 184 mm of rains during the period from 16/0425 through 16/1010 UTC. According to the analysis from NSMC/CMA (the National Satellite Meteorological Center, a sub-agency of China Meteorological Agency), the Luoyuan rainfall event was caused by the periphery of Tropical Depression Hagupit. (NOTE: The formal NMCC track for Hagupit ended at 09/1306 UTC. This TCWC, however, did mention the system as a tropical depression in several Weather Forecasts during the re-generating stage of Hagupit. Two other TCWCs, the Central Weather Bureau of Taiwan and the Japanese Meteorological Agency, did not downgrade Hagupit from tropical depression status until 17/0000 UTC.) Hundreds of houses were inundated with 1700 residents being affected by the torrential rains in Luoyuan County. (Report written by Kevin Boyle with significant contributions by Huang Chunliang) TROPICAL STORM CHANGMI (TS 0219) 18 - 25 September ------------------------------------------ Changmi: contributed by South Korea, is the name for the flower 'rose' Tropical Storm Changmi was the second NWP system of 2002 to be named as a tropical storm by JMA, but which was not recognized as a tropical storm by JTWC. The other was Tropical Storm Kalmaegi, which was classi- fied as a tropical depression by JTWC. With Kalmaegi, it was a matter of intensity but with Changmi, it was a matter of cyclone type. JTWC regarded Changmi as an extratropical LOW, hence, did not issue tropical cyclone warnings on the system. As was the case with Kalmaegi, NMCC did regard Changmi as a tropical storm and issued five warnings on the system. Whether a tropical storm or not, Changmi's roots did lie in the tropics. JTWC issued a STWO at 1600 UTC on 15 September, noting that an area of convection had developed approximately 135 nm north-northeast of Chuuk. Animated infrared satellite imagery showed weak cycling convection associated with a possible weak LLCC. A 200-mb analysis indicated that the disturbance had good divergence aloft by virtue of being situated in the southwestern quadrant of a subtropical ridge. Vertical shear was moderate with strong westerlies to the south. At 0600 UTC on the 16th the disturbance was located about 240 nm north of Chuuk, but by 17/0100 UTC the main area of interest had shifted to a position approximately 330 nm east-northeast of Guam. Cycling deep convection was noted in association with a weak LLCC embedded in the monsoon trough. The potential for development was upgraded to fair at 0000 UTC on 18 September--a partially-exposed LLCC was located about 440 nm north- northeast of Guam with cycling deep convection. A TCFA was issued for the disturbance at 1200 UTC as deep convection had increased and CIMSS products indicated good divergence aloft with favorable vertical shear. At the same time, JMA classified the system as a 30-kt tropical depression; however, it appears that JMA was following another center. The JTWC position was approximately 380 nm southeast of Iwo Jima, or near 20.1N, 146.0E, while the JMA position was at 18.7N, 145.0E, or near Agrihan Island. As the system moved northward, the northernmost (JTWC) center became fully-exposed and the southernmost center (JMA) became the dominant one. JTWC cancelled the TCFA at 1100 UTC on the 19th, noting that animated infrared imagery indicated that the system was rotating cyclonically around and beginning to merge with the second circulation to the south. At 19/1200 UTC, JMA downgraded the tropical depression they had been following to a low-pressure area. The weak system continued northward with little change on the 20th, passing about 175 nm due west of Iwo Jima at 21/0000 UTC. The STWO from JTWC at 21/0600 UTC noted that multiple exposed LLCCs were evident south of an area of deep convection. A 200-mb analysis indicated moderate shear associated with an upper-level ridge northeast of the area. A second TCFA was issued at 1000 UTC, locating a partially-exposed LLCC with increasing deep convection about 250 nm northwest of Iwo Jima. (JMA at this time was classifying the system as a weak (i.e., 25-kt) depression.) At 0200 UTC on 22 September the LOW was located approxi- mately 340 nm north-northwest of Iwo Jima. Multiple exposed LLCCs were seen southeast of the deep convection, and a 200-mb analysis indicated increasing vertical shear affecting the system as it interacted with mid-latitude flow. In the meantime, at 22/0000 UTC, JMA suddenly upgraded the system to Tropical Storm Changmi with 40-kt (10-min avg) winds, located roughly 375 nm south-southwest of Tokyo. (NMCC also initiated warnings on Changmi as a 40-kt tropical storm at the same time.) JTWC, however, cancelled the TCFA at 0400 UTC and dropped the system from their tropical weather products. The TCFA cancellation stated that extensive dry air entrainment as the system accelerated to the northeast was indicative of a developing extratropical LOW. JMA upped Changmi's intensity to 45 kts at 22/0600 UTC while NMCC maintained their MSW estimate at 40 kts throughout the period for which they issued warnings on the storm. Changmi scooted on east-northeastward and by 23/0000 UTC had become extratropical approximately 300 nm east of Tokyo. The storm intensified as it became extratropical with JMA upping the winds to 50 kts at 0000 UTC. The storm continued northeastward over the next few days and intensified into a deep extratropical cyclone with hurricane force winds. The storm crossed the Dateline a little after 0600 UTC on the 25th and at 1800 UTC, when last referenced in JMA's bulletins, was a 958-mb storm with 65-kt winds in the Bering Sea. It isn't exactly clear to the author just what the character of this cyclone was on 22 September when it was named by JMA. It seems possible that it was some sort of subtropical or hybrid system. JMA and NMCC would likely not have classified it as a tropical storm had it already merged with a cold front--the primary signature of a classic extra- tropical cyclone. Infrared satellite imagery around the time it was named reveals an exposed center with all the convection to the north, so it possibly could be classified as a sheared tropical cyclone. No damage or casualties are known to have resulted from Tropical Storm Changmi. (Report written by Gary Padgett) TROPICAL STORM MEKKHALA (TC-24W / TS 0220) 23 - 28 September ------------------------------------------- Mekkhala: contributed by Thailand, means 'angel of thunder' A. Storm Origins ---------------- On 21 September, at 0600 UTC, JTWC issued a STWO for a new area of convection located in the South China Sea approximately 375 nm east- southeast of Hue City, Vietnam. The system was depicted in multi- spectral imagery as an elongated trough with deep convection associated with convergence to the south. The development potential was rated as poor on this STWO, based on moderate wind shear conditions and weak divergence aloft. However, during the next 24 hours conditions became more conducive for development and based on this, the 22/0600 UTC STWO upgraded the potential for development to fair. Animated multispectral imagery depicted improved organization of the deep convection at this time. Conditions continued to become more favourable with lighter vertical wind shear and improved poleward outflow, and three hours later, JTWC issued a TCFA. A 22/0620 UTC AMSU sensor image indicated a well- defined LLCC. The development potential remained good on the 23/0600 UTC STWO (a second TCFA was issued at the same time) despite the disorganized appearance of the deep convection. QuikScat imagery in combination with synoptic reports revealed weak winds near the centre with 20 to 25-kt winds to the south and north. The first warning on Tropical Depression 24W was issued by JTWC at 1200 UTC, 23 September, locating the center near 15.1N, 112.1E, or about 275 nm east-southeast of Hue City, Vietnam. (HKO also began issuing bulletins at this time). TD-24W was moving north-northwestward at 4 kts with a MSW of 25 kts. Animated enhanced infrared imagery indicated that the deep convection continued to cycle and consolidate near the LLCC. However, a 23/1415 UTC SSM/I pass suggested that the mid-level circulation centre was displaced just northeast of the LLCC. A later SSM/I pass (at 23/2252 UTC) showed convective rainbands curving into the LLCC. The MSW was increased a little to 30 kts at 24/0000 UTC as the system continued to move north-northwestward. (NMCC began releasing warnings at 24/0600 UTC.) At 24/1200 UTC, TD-24W was centred approximately 130 nm south-southeast of Hainan Dao or near 16.2N, 109.9E. Animated satellite imagery indicated that deep convection had consolidated over the LLCC by this time. B. Track and Intensity History ------------------------------ JTWC upgraded the system to tropical storm status at 24/1800 UTC based on the appearance of a banding eye feature and deep convection south of the LLCC which was revealed by a 24/1359 UTC SSM/I pass. Satellite CI estimates rose to 3.0/3.5 at 25/0000 UTC as the tropical cyclone continued moving north-northwestward to a position approximately 35 nm south-southeast of Hainan Dao. Animated water vapour imagery showed poleward outflow being enhanced by a passing shortwave trough. At 25/0300 UTC JMA upgraded the system to tropical storm status, assigning the name Mekkhala. (HKO and NMCC had upgraded the system to a tropical storm at 25/0000 UTC.) Tropical Storm Mekkhala reached its peak intensity of 55 kts at 25/1200 UTC as it moved over Hainan Dao. (JMA and NMCC both estimated the peak 10-min avg MSW at 45 kts while HKO's peak intensity was 40 kts.) The mid-level ridge that was moving Mekkhala on a north-northwesterly course began to weaken as a developing longwave trough moved eastward into it. This caused the cyclone to move more in a northerly direction and slow to a speed of 4 to 5 kts. A weakening trend had begun as unfavourable conditions and land effects started to take their toll. By 26/1800 UTC the MSW had fallen to 35 kts. Convection began to decrease, covering mainly the southern quadrant of the partially-exposed LLCC, as revealed by 26/1307 UTC SSM/I imagery. Mekkhala was downgraded to a tropical depression by JTWC at 27/0000 UTC while located over the Gulf of Tonkin near 21.4N, 108.4E. However, JMA and NMCC continued to classify Mekkhala as a tropical storm (MSW 10-min avg) until 28/0000 UTC while HKO did not downgrade the system until 28/0300 UTC (on the final warning). At 27/0600 UTC the LLCC of Mekkhala had moved slowly northward onto the coast of southern China near the city of Gang. JTWC ceased issuing advisories on the system at this time. Mekkhala came almost to a standstill as it meandered off the coast of China. Associated convection decreased during 28 September and the Asian TCWCs had ceased issuing warnings by 28/0600 UTC. The low-level remains were no longer discernible in satellite imagery by 30 September. Editor's Note - An infrared image of Mekkhala taken at 1833 UTC on 27 September was recently sent to me. This was taken 12 hours after JTWC's final warning, but distinctly shows an eye-like feature on the coast in the northern Gulf of Tonkin region. JMA and HKO were still estimating the intensity (10-min avg) at 35 kts at that time, and NMCC was reporting 45 kts. JTWC's final warning had been issued at 27/0600 UTC with the MSW (1-min avg) estimated at 25 kts, but Weizhou Dao in the northern Gulf of Tonkin had reported sustained winds between 41 and 47 kts, gusting to hurricane force, around 0400 UTC. Also, Beihai on the coast reported sustained gale-force winds gusting to storm force (time unknown). These observations, plus the image noted above, suggest that the Asian TCWCs were correct in maintaining Mekkhala as a tropical storm through early on the 28th. C. Meteorological Observations ------------------------------ The rainfall reports below were sent by Huang Chunliang of Fuzhou City, Fujian Province, China. A special thanks to Chunliang for compiling and sending the information. Most of the amounts tabulated are 24-hour totals, and I have included only those exceeding 100 mm. (1) Rainfall Reports from the Meteorological Service of Guangdong In Guangdong Province, three counties reported rainfall amounts that exceeded 100 mm. 27/0000--28/0000 UTC: Cities Stations Rainfall (mm) -------- -------- ------------- Qingyuan Qingyuan 107.0 28/0000--29/0000 UTC: Cities Stations Rainfall (mm) --------- --------- ------------- Jiangmen Shanchuan 163.9 Zhanjiang Leizhou 148.1 (2) Rainfall Reports from Sanya City, Hainan Province Periods Rainfall (mm) -------------------- ------------- 24/0000--25/0000 UTC 104.5 25/0000--25/0600 UTC 124.0 25/0000--26/0000 UTC 343.1 (3) Rainfall Reports from the Meteorological Services of Hainan and Guangxi 23/0000--25/0000 UTC: Qiongzhong, Hainan 114 mm 24/0000--25/1200 UTC: Lingshui, Hainan 230 mm Baoting, Hainan 201 mm 24/0000--26/1200 UTC: Sanya, Hainan 478.9 mm Lingshui, Hainan 327.9 mm Baoting, Hainan 295.9 mm Wuzhishan, Hainan 287.2 mm Ledong, Hainan 103.4 mm 25/0000--26/0000 UTC: Lingshui, Hainan 227 mm 26/0000--27/0000 UTC: Dongfang, Hainan 164 mm 27/0000--28/0000 UTC: Beihai, Guangxi 316 mm Hepu, Guangxi 342 mm Lingshan, Guangxi 105 mm Weizhou Dao, Guangxi 280 mm (5) Wind Observations from Guangxi Weizhou Dao reported sustained winds of Beaufort Force 9 (41-47 kts), gusting to force 12 (64 kts) before noon on the 27th (locally). Meanwhile, Beihai reported sustained winds of Beaufort Force 8 34-40 kts), gusting to force 10 (48-55 kts). D. Damage and Casualties ------------------------ (1) Hainan Province A press report indicated that more than 6500 residents who were trapped in the floods were rescued by the local government. Also, 84 fishermen were rescued at sea, though another one was reported missing. Five cities/counties recorded rains exceeding 200 mm during the 3-day period ending at 27/0000 UTC with Sanya reporting the highest amount of 478.9 mm. According to the preliminary statistics on 28 September, some 938,800 residents were seriously affected by the storm with 2500 houses collapsing. Direct economic losses in the province were estimated to have been approximately 666.7 million yuan. (2) Guangxi Region Approximately 1,248,000 residents in Beihai and Qinzhou Cities were affected by storm damage. In Beihai City, 335 houses collapsed in the storm. According to the preliminary statistics, the direct economic losses were estimated to have been approximately 182.2 million yuan in the city. (3) Guangdong Province At around 26/0300 BJT (or 25/1900 UTC), Jinhe Town, Xuwen County was struck by a tornado in which 95 houses were partly damaged, resulting in three injuries. Also, Taiping Town, Mazhang District was hit by another tornado around 26/0500 BJT (or 25/2100 UTC). Both the tornadoes caused severe economic losses in the towns, though no monetary estimates were specified in the official report. (Report written by Kevin Boyle with significant contributions by Huang Chunliang) SUPER TYPHOON HIGOS (TC-25W / TY 0221) 26 September - 5 October -------------------------------------------- Higos: contributed by the United States, is the Chamorro word for the fruit 'fig' A. Storm Origins ---------------- An area of convection developed on 25 September approximately 190 nm north of Eniwetok. Animated visible satellite imagery revealed weak cycling convection associated with a weak LLCC while an upper-level analysis indicated that the system had good equatorward and poleward outflow. The disturbance was located in the southwest quadrant of the subtropical ridge where vertical shear was weak. By 0600 UTC on the 26th deep convection was increasing near a partially-exposed LLCC and the potential for development had been upgraded to fair. However, at 26/0630 UTC JTWC issued a TCFA for the system, upgrading the development potential to good, and at 0900 UTC the first warning on Tropical Depression 25W was issued. The initial MSW was estimated at 25 kts and the center was located approximately 560 nm east of Saipan, moving westward at 13 kts. A 26/0953 UTC SSM/I pass depicted a well-defined LLCC with a curved rain band in the southern semicircle, and the MSW was upped to 30 kts at 1200 UTC. The depression was tracking westward along a low to mid- level ridge situated to its north, and this motion was forecast to continue for another 24 to 36 hours. Convective organization continued to increase and by 27/0000 UTC, CI estimates had reached 35 and 45 kts, so JTWC upgraded TD-25W to tropical storm status. The system was then located approximately 370 nm east of Saipan, moving west-northwestward at 14 kts. B. Track and Intensity History ------------------------------ The MSW was increased to 45 kts at 27/0600 UTC. At the same time both JMA and NMCC upgraded the system to tropical storm status with JMA assigning the name Higos. A 27/1132 UTC SSM/I pass indicated a banding eye with increased symmetric deep convection around the LLCC. The intensity was upped to 55 kts at 1200 UTC, and at 1800 UTC JTWC upgraded Higos to a 65-kt typhoon, based on CI estimates of 65 and 77 kts. Higos was then located approximately 150 nm north-northeast of Saipan, tracking west-northwestward at 18 kts. Around 28/0000 UTC Typhoon Higos passed just south of the island of Pagan. The maximum sustained wind recorded was 51 kts with peak gusts of 99 kts. The storm continued tracking west- northwestward at a pretty good clip and steadily intensified. An 8-nm diameter eye was noted at 1200 UTC, and by 1800 UTC satellite CI esti- mates were 90, 102, and 115 kts. JTWC increased the MSW to 105 kts in the 1800 UTC warning, locating the center about 315 nm south of Iwo Jima. (JMA and NMCC both had upgraded Higos to typhoon status at 28/1200 UTC.) Typhoon Higos intensified rather rapidly on 29 September--the MSW was raised to 120 kts at 29/0000 UTC, and at 0600 UTC the intensity was upped to 130 kts, making Higos the seventh super typhoon of the year. JTWC's estimated peak intensity for Higos was 135 kts at 29/1200 UTC, based on CI estimates of 127 and 140 kts. Storm-force winds reached outward from 40-60 nm around the 20-nm eye, and gales extended out up to 150 nm in the northeast quadrant and to 110 nm in the southern semicircle. JMA's and NMCC's peak 10-min avg MSW estimates for Higos were 90 kts and 100 kts, respectively, and the minimum central pressure estimated by JMA was 935 mb. Super Typhoon Higos was located approximately 340 nm southwest of Iwo Jima at the time of its peak intensity, and had turned more toward the northwest as the subtropical ridge to the north weakened and shifted eastward. By 1800 UTC some erosion of the eyewall had occurred in the southwest quadrant so the MSW was reduced slightly to 130 kts. Early on 30 September a longwave trough extended from the Yellow Sea into the East China Sea and was moving eastward. This trough was fore- cast to interact with Higos and recurve and accelerate the typhoon toward the northeast. At 30/0000 UTC the super typhoon was located roughly 330 nm west-southwest of Iwo Jima and had already turned to the north into a weakness in the subtropical ridge. Poleward outflow was being enhanced by the approaching trough but eyewall erosion continued in the western semicircle, suggesting that the system was being sheared from the west. Dry air entrainment continued to increase also and the MSW was reduced to 120 kts at 0600 UTC, and further to 110 kts at 1200 UTC. Typhoon Higos by then was located about 650 nm south-southwest of Tokyo, moving north-northeastward at 15 kts. The western quadrants continued to weaken while enhanced infrared imagery revealed an 18-nm diameter eye. On 1 October the typhoon continued to accelerate north-northeastward in the southwesterly flow from the longwave trough to the west. At 01/0000 UTC Higos was located approximately 380 nm south-southwest of Tokyo, moving north-northeastward at 26 kts with the MSW still estimated at 110 kts. (JMA and NMCC were reporting 80 and 90 kts, respectively, at 0000 UTC.) By 0600 UTC the center of Higos was about 185 nm south- southwest of the Japanese capital, racing north-northeastward at 32 kts. JTWC decreased the MSW slightly to 95 kts on this warning. The center of the typhoon roared inland near Yokosuka at approximately 1100 UTC and by 1200 UTC was inland very near Tokyo. Yokosuka reported peak sustained winds of 51 kts (presumably 10-min avg) with gusts to 65 kts as Higos made landfall. Station Irozaki (WMO 47666) in Shizuoka Prefecture recorded a peak gust of 103 kts shortly before 0900 UTC. This is the highest wind measurement of which the author is aware. Even though Higos was in the process of extratropical transition as it made landfall, the very rapid translational speed allowed the storm to move to very high latitudes while retaining some tropical characteristics. Several stations in Japan reported peak wind gusts exceeding 80 kts, and station Urakawa (WMO 47426) on Hokkaido reported a peak gust of 87 kts at 01/1943 UTC. At 01/1800 UTC, JMA and NMCC downgraded Higos to a tropical storm while JTWC maintained minimal typhoon status through 02/0000 UTC. At 1800 UTC the storm was located over northeastern Honshu and tracking north-northeastward at 51 kts. Satellite imagery, radar and synoptic data indicated that the LLCC had become decoupled west of the mid-level vortex. The extremely rapid translational speed resulted from strong poleward steering flow caused by the combination of the longwave trough to the west and a mid-level high center to the east. JTWC downgraded Higos to tropical storm status at 02/0000 UTC. The cyclone was then over western Hokkaido about 55 nm north of Sapporo, tracking northward at 33 kts. The final JTWC warning was issued at 0600 UTC on the 2nd, placing the by now extratropical cyclone's center approximately 200 nm north of Sapporo. NMCC also issued their final warning on Higos at 02/0600 UTC, although locating the center about 70 nm west of JTWC's position. The 02/0600 UTC position (from JTWC) was also very near the southern tip of Russia's Sakhalin Island, and the cyclone moved northward over the island as a slowly weakening extratropical gale. JMA declared the system extratropical at 1200 UTC when the storm was centered along the western coast of southern Sakhalin. The storm had reached the central Sakhalin area by 03/0000 UTC and thence turned eastward into the Sea of Okhotsk. The LOW continued eastward, crossing the southern tip of the Kamchatka Peninsula around 04/0000 UTC and entering the Bering Sea as a 35-kt gale. By 0600 UTC on 6 October the former super typhoon had weakened to a 1000-mb LOW with winds below gale force, located just west of the Dateline in the extreme southwestern Aleutian Islands. C. Meteorological Observations ------------------------------ Huang Chunliang has sent me some rainfall and wind observations from Japan which he compiled from information given on JMA's website. A special thanks to Chunliang for preparing the report and passing it along. (1) Rainfall Observations - The amounts tabulated represent 24-hourly totals for the indicated dates. The dates are local Japanese time (UTC+9), so the UTC times would span from 1500 UTC of the previous date to 1500 UTC of the indicated date. Only amounts greater than 100 mm are listed. 1 October --------- Prefecture Station WMO Code Altitude (m) Rainfall (mm) ------------------------------------------------------------------- Tokyo Oshima 47675 74 131.0 Saitama Chichibu 47641 232 208.0 Tochigi Nikko 47690 1292 181.5 Yamanashi Kawaguchiko 47640 860 152.5 Shizuoka Ajiro 47668 67 102.5 Shizuoka Mishima 47657 21 157.5 Shizuoka Shizuoka 47656 14 105.0 Shizuoka Hamamatsu 47654 32 118.0 Shizuoka Omaezaki 47655 45 131.0 Aichi Irako 47653 6 142.0 Fukushima Wakamatsu 47570 212 155.0 Fukushima Shirakawa 47597 355 102.0 Iwate Miyako 47585 43 105.0 2 October --------- Prefecture Station WMO Code Altitude (m) Rainfall (mm) ------------------------------------------------------------------- Hokkaido Hiroo 47440 32 112.5 The following table contains rainfall amounts from some additional JMA stations (non-WMO stations). Only amounts greater than 200 mm are given. 1 October --------- Prefecture Station JMA Code Altitude (m) Rainfall (mm) ------------------------------------------------------------------- Kanagawa Hakone 46161 850 342 Saitama Tokigawa 43162 295 203 Saitama Urayama 43157 400 215 Tochigi Shioya 41181 123 255 Tochigi Happagahara 41081 1087 223 (2) Maximum Sustained Wind and Pressure Observations - The values listed represent the peak hourly 10-min mean winds and minimum pressure observations for the indicated stations. If the minimum pressure occurred at a different time than the peak sustained wind, the time of the minimum pressure is given in parentheses. The pressure measurements have been adjusted to mean sea level. Station WMO Code MSW (kts) Time (UTC) Min SLP (mb) ------------------------------------------------------------------- Tateyama 47672 35 SSW 01/1100 967.9 Katsuura 47674 50 SSW 01/1200 974.4 (1100 UTC) Choshi 47648 50 SW 01/1200 970.5 (1100 UTC) Chiba 47682 37 SW 01/1300 956.8 (1000 UTC) Oshima 47675 54 SSW 01/1300 977.5 (1200 UTC) Hachijo Jima 47678 45 W 01/0900 981.1 (0800 UTC) Ishinomaki 47592 45 ESE 01/1400 973.7 (1500 UTC) Miyako 47585 38 SE 01/1500 990.1 Ofunato 47512 41 SE 01/1600 975.7 Kushiro 47418 46 SSW 02/0300 991.2 (2200 UTC) Nemuro 47420 37 ESE 01/2100 996.0 (2300 UTC) Urakawa 47426 46 ESE 01/2000 982.3 Nii Shima 44206 ** 51 W 01/1100 N/A Haneda 44166 ** 45 ESE 01/1000 N/A Shinkiba 44136 ** 47 W 01/1200 N/A ** - JMA station codes (3) Gust Observations - The values given represent the peak wind gust recorded in association with the passage of Typhoon Higos. Prefecture Station Code Time (UTC) Gust (kts) ------------------------------------------------------------------ Tokyo Kozu Shima 44211 ++ 01/0700 58 Shizuoka Irozaki 47666 01/0900 103 ** Chiba Choshi 47648 01/1200 98 Fukushima Iwaki N/A 01/1310 93 Miyagi Ishinomaki 47592 01/1320 80 Iwate Ofunato 47512 01/1530 83 Iwate Miyako 47585 01/1610 80 Hokkaido Urakawa 47426 01/1943 87 ++ - JMA station code - all others are WMO codes ** - second strongest gust recorded in station's history D. Damage and Casualties ------------------------ Damage in Japan due to Typhoon Higos appears to have been relatively light. There were some houses unroofed, and 80,000 households were without electrical power at one point. A 56,835-ton cargo ship registered in the Bahamas and carrying automobiles ran aground on Oshima, an island south of Tokyo, but none of the crew of 22 were injured. Ferries heading south of Tokyo were cancelled, along with about 200 evening flights into and out of Tokyo airport. There was concern that the apple and rice crops would be heavily damaged since the storm struck just before harvest time, but the author has not learned of any effects the storm had on those crops. Press reports indicate that five persons lost their lives in Japan due to Typhoon Higos. Two persons died in Chiba Prefecture, near Tokyo, when they were electrocuted by electrical cables, and a security guard was killed when a plate glass window fell on him in Yokohama, about 30 km from Tokyo. An Indonesian man drowned while trying to secure a fishing boat in Miyagi in northern Japan, and the body of a missing woman was recovered after being swept away by waves on the coast near Yokohama. (Report written by Gary Padgett with significant contributions by Huang Chunliang) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for September: No tropical cyclones ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for September: 1 tropical depression ** ** - treated as a minimal tropical storm by JTWC Sources of Information ---------------------- The primary sources of tracking and intensity information for Southwest Indian Ocean tropical cyclones are the warnings issued by the Tropical Cyclone Warning Centre on La Reunion Island, part of Meteo France (MFR), and the Regional Specialised Meteorological Centre for the basin. However, tropical cyclones in this region are named by the sub-regional warning centres on Mauritius and Madagascar with longitude 55E being the demarcation line between their respective areas of warning responsibility. The La Reunion centre only advises these agencies regarding the intensity of tropical systems. References to sustained winds imply a 10-minute averaging period unless otherwise stated. In the companion tropical cyclone tracks file, I occasionally annotate positions from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii, when they differ from MFR's coordinates by usually 40-50 nm or more. The JTWC warnings are also the source of the 1-minute average maximum sustained wind values included in the tracks file. Additionally, information describing details of satellite imagery and atmospheric circulation features included in the narratives is often gleaned from the JTWC warnings. A special thanks to Kevin Boyle for writing the report on Tropical Depression 01S. Southwest Indian Ocean Tropical Activity for September ------------------------------------------------------ The first September tropical system to warrant any warnings in four years formed early in the month at a very low latitude east of the Seychelles Islands. In September, 1998, La Reunion issued warnings on two tropical disturbances, neither of which were deemed to have reached tropical depression status (30 kts). However, the second of those systems was classified as a minimal tropical storm by JTWC. This year's system was classified as a tropical depression by MFR and as a minimal tropical storm by JTWC. However, the damage reports from the Seychelles certainly suggest that it could have been significantly stronger. TROPICAL DEPRESSION (MFR 01 / TC-01S) 5 - 8 September --------------------------------------- A. Storm History ---------------- The first mention by JTWC of the disturbance that was to become TC-01S was in a STWO issued at 1800 UTC on 27 August. The disturbance was located approximately 80 nm east-northeast of Diego Garcia near 6.3S, 77.0E, and was accompanied by a weak LLCC and scattered deep convection. The potential for development of the disturbance was noted as poor in this STWO. The development potential remained poor on the next STWO issued at 28/0500 UTC. (The STWOs for 29 and 30 August are missing.) The 31/1800 UTC STWO noted convergence-induced cycling deep convection around a weak LLCC with the system embedded in a near-equatorial trough. The development potential remained rated as poor in the 02/1800 UTC STWO. The disturbance remained disorganized and upper-level northeasterlies were shearing the deep convection. The disturbance weakened and was no longer considered a suspect area for further development by 04/1800 UTC. However, a 04/1241 UTC QuikScat pass continued to show a weak circulation near 3.6S, 71.4E, or about 240 nm north-northwest of Diego Garcia, and there was still surface convergence into the region. An intense burst of convection signaled the start of new development and at 05/1500 UTC, JTWC issued an interim STWO upgrading the development potential to fair. Animated infrared imagery and a mid-level analysis indicated a well-marked mid-level circulation, but there was, at this time, no evidence of a LLCC. Also, MFR had begun issuing warnings on the disturbance at 05/1200 UTC, indicating 25-kt winds (10-min avg) near the centre with 30-kt winds in isolated locations in the southern semi- circle. MFR upgraded the disturbance to tropical depression status with 30-kt winds at 1200 UTC on 6 September, and JTWC issued their first warning on Tropical Cyclone 01S at 06/1800 UTC. The system was centred near 4.0S, 57.8E, or approximately 150 nm east-northeast of Victoria in the Seychelles. SSM/I and animated satellite imagery at this time showed a small system of approximately 100 nm with a banding feature wrapping into the centre from the southeast. TC-01S was moving west-southwestward at 11 kts with the MSW estimated to be 35 kts. (This was the peak intensity for JTWC--Reunion's peak was 30 kts 10-min avg, which corresponds to a 1-min avg MSW of 35 kts, so the two TCWCs were in good agreement.) The heading turned westerly and satellite imagery and a SSM/I pass at 07/0529 UTC depicted deep convection sheared southwest of the LLCC. This was caused by upper-level easterlies which began to inhibit further development. The weakening system continued westward at 8 kts until the LLCC lost identity and all that remained was cycling deep convection. MFR downgraded the system from tropical depression status back to 25 kts at 07/1200 UTC, and JTWC decreased the 1-min avg MSW to 30 kts six hours later. The dominant steering flow for this system was a low to mid- level ridge extending from the East Coast of Africa. Both JTWC and MFR issued their final warnings on TC-01S at 08/0600 UTC. The weakening centre was then located approximately 100 nm west-northwest of the Seychelles. B. Meteorological Observations ------------------------------ According to press reports heavy rainfall and strong winds badly affected the Seychelles Islands. The islands of Mahe and Praslin recorded rainfall amounts of up to 327 mm and 125 mm, respectively. Winds of up to 71 kts (likely gusts) were recorded on Praslin. This suggests that TC-01S was possibly significantly stronger than the maximum intensity reported by both JTWC and MFR. Gusts of this magnitude near sea level could imply 10-min avg winds of 50 kts. However, the altitude at which the observations were made isn't known. The strong winds could have been very localised and not representative of the strength of the overall circulation. C. Damage and Casualties ------------------------ Close to 10 per cent of the Seychelles' population of 75,000 was directly affected by the tropical depression, and 375 families were forced to abandon their homes and seek refuge either with friends or relatives. The strong winds caused damage to housing, public buildings, roads, power supplies and telecommunications. Flooding was severe in Grand Anse, Anse Kerlan, Baie St Anne, Cote D'or and Mont Plaisir, where some villages and settlements were literally submerged by water. Many hectares of cultivated land were destroyed. There are no reports of casualties. (Report written by Kevin Boyle) ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for September: No tropical cyclones ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for September: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for September: No tropical cyclones ************************************************************************* EXTRA FEATURE In order to shorten the amount of typing in preparing the narrative material, I have been in the habit of freely using abbreviations and acronyms. I have tried to define most of these with the first usage in a given summary, but I may have missed one now and then. Most of these are probably understood by a majority of readers but perhaps a few aren't clear to some. To remedy this I developed a Glossary of Abbreviations and Acronyms which I first included in the July, 1998 summary. I don't normally include the Glossary in most months in order to help keep them from being too long. If anyone would like to receive a copy of the Glossary, please e-mail me and I'll be happy to send them a copy. ************************************************************************* AUTHOR'S NOTE: This summary should be considered a very preliminary overview of the tropical cyclones that occur in each month. The cyclone tracks (provided separately) will generally be based upon operational warnings issued by the various tropical cyclone warning centers. The information contained therein may differ somewhat from the tracking and intensity information obtained from a "best-track" file which is based on a detailed post-seasonal analysis of all available data. Information on where to find official "best-track" files from the various warning centers will be passed along from time to time. The track files are not being sent via e-mail. They can be retrieved in the following manner: (a) FTP to: hrd-type42.nhc.noaa.gov [140.90.176.206] (b) Login as: anonymous (c) For a password use your e-mail address (d) Go to "data" subdirectory (Type: cd data) (e) Set file type to ASCII (Type: ascii) (f) Transfer file (Type: get remote_file_name local_file_name ) (The files will be named with an obvious nomenclature--using September as an example: sep02.tracks) (g) To exit FTP, type: quit Both the summaries and the track files are standard text files created in DOS editor. Download to disk and use a viewer such as Notepad or DOS editor to view the files. The first summary in this series covered the month of October, 1997. If anyone wishes to retrieve any of the previous summaries, they may be downloaded from the aforementioned FTP site at HRD. The summary files are catalogued with the nomenclature: sep02.sum, for example. Back issues can also be obtained from the following websites (courtesy of Michael Bath, Michael V. Padua and Michael Pitt): OR Another website where much information about tropical cyclones may be found is the website for the UK Meteorological Office. Their site contains a lot of statistical information about tropical cyclones globally on a monthly basis. The URL is: TROPICAL CYCLONE REPORTS AVAILABLE JTWC now has available on its website the complete Annual Tropical Cyclone Report (ATCR) for 2001 (2000-2001 season for the Southern Hemisphere). ATCRs for earlier years are available also. Recently added was the report for the Southern Hemisphere 2001-2002 season. The URL is: Also, TPC/NHC has available on its webpage nice "technicolor" tracking charts for the 2001 Atlantic and Eastern North Pacific tropical cyclones; also, preliminary storm reports for all the 2001 Atlantic and Eastern North Pacific cyclones are now available, as well as track charts and reports on storms from earlier years. The URL is: A special thanks to Michael Bath of McLeans Ridges, New South Wales, Australia, for assisting me with proofreading the summaries. PREPARED BY Gary Padgett E-mail: garyp@alaweb.com Phone: 334-222-5327 John Wallace (Eastern North Pacific, North Indian Ocean, Western Gulf of Mexico) E-mail: dosidicus@aol.com Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South China Sea) E-mail: newchapelobservatory@btinternet.com Simon Clarke (Northeast Australia/Coral Sea, South Pacific) E-mail: simon_clarke@iprimus.com.au ************************************************************************* ************************************************************************* >> Uploaded: 12-14-02 / Typhoon2000.com / Typhoon2000.ph