GARY PADGETT'S MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY AUGUST, 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.) ************************************************************************* AUGUST HIGHLIGHTS --> Northwest Pacific still quite active with four typhoons --> Okinawa, Korea and China experience typhoon strikes --> Another Category 5 hurricane in the Eastern Pacific --> Central Pacific produces a hurricane/typhoon --> Some minor tropical storms in the Atlantic ************************************************************************* ***** Feature of the Month for August ***** A CYCLONE PHASE SPACE DERIVED FROM THERMAL WIND AND THERMAL ASYMMETRY This monthly feature is the second in a series highlighting some of the papers presented at the recent AMS 25th Conference on Hurricanes and Tropical Meteorology in San Diego, California. As previously explained, three of the papers really excited me as they introduced new and innovative solutions to some of the problematic issues and challenges facing tropical cyclone forecasters today. One of the often challenging issues that operational forecasters have to deal with is the determination of the point at which a tropical cyclone undergoing extratropical transition should be categorized as fully extratropical and no longer requiring tropical-type warnings. A related problem concerns the classification of subtropical/hybrid systems. Some warning centers do not operationally employ a subtropical cyclone category, but for those which do, it is often difficult to decide just when a particular storm system warrants formal subtropical cyclone warnings (which are similar in format to tropical cyclone warnings). And furthermore, if a subtropical storm is so classified operationally, the point at which to designate it as a tropical cyclone--if at all--is often not easy to decide. In general, prior to the satellite era, oceanic storms were basically considered as belonging to two categories: tropical and extratropical. Tropical cyclones by and large formed in the tropics or over warm subtropical waters and were considered warm-core and non-frontal. Extratropical cyclones were considered to be frontal cyclones through part of their life cycles and also cold-core. Any exceptions, i.e., warm-core frontal LOWs or non-frontal cold-core LOWs, were usually just considered rare exceptions to the rule. Regular satellite coverage of the oceans by the late 1960s had revealed the occurrence of a regular class of cyclones, at least in the North Atlantic, which at some point of their life cycles were distinctly not connected to a surface cold front and had some organized convection, but were not warm-core either as a tropical cyclone should be. Moreover, many of these eventually evolved into storms with convective warm cores very much like tropical cyclones. Hence, the "birth" of the subtropical cyclone in Atlantic terminology. A few years later, infrared satellite imagery had begun to reveal that certain rapidly developing extratropical LOWs, especially off the U. S. East Coast but also in other basins, often exhibited warm cores but were also frontal. Thus, the waters became even more muddied. Often synoptic-scale cyclones have been referred to as a spectrum, usually depicted on a single axis with extratropical cyclones at one end and classic tropical cyclones at the other. Subtropical storms, polar LOWs, and other types of hybrid systems were placed at various points on the axis between the extremes. Some years ago Jack Beven of TPC/NHC devised a cyclone classification square in which the horizontal axis depicted frontal characteristics and the vertical axis represented the the thermal properties of the core. Thus, subtropical cyclones (non-frontal and cold-core) were placed at the lower left corner, classic extratropical cyclones (frontal and cold-core) at the lower right, tropical cyclones (non-frontal and warm-core) at the upper left, and extratropical "bombs" (frontal and warm-core) at the upper right. Systems such as monsoon depressions, polar LOWs, and "strange" hybrids were placed at various positions on the square. The scheme was a neat idea and helped to put things in a better perspective, but was very general and not quantified. Recently Bob Hart of Pennsylvania State University, along with Jenni Evans also of Penn State, devised a new technique which shows great promise in providing some rigorous, quantitative guidance in classifying cyclones. To generalize, it could be said that the cyclone phase space, as it is called, is a quantification and an extension to three dimensions of Jack's earlier diagram. The title of the poster which was presented at the poster session was "A Cyclone Phase Space Derived From Thermal Wind and Thermal Asymmetry". A special thanks to Bob and Jenni for giving me their permission to feature the cyclone phase space and for reviewing this article. The introductory paragraph written by Bob Hart for the poster session abstract defines the purpose and the usefulness of such a technique. "It is often difficult to distinguish tropical cyclone (TC) development from subtropical cyclone development or hybrid cyclone development within operational forecast models. Yet, knowledge of the nature of the forecast cyclone development within those models is essential to quantifying the potential threat and intrinsic intensity forecast uncertainty associated with that cyclone. Further, the accurate forecasting of extratropical transition of a TC is crucial to the type and extent of marine and public warnings issued. Thus, for both the extratropical cyclone and tropical cyclone communities, diagnostics indicating cyclone phase may be helpful for providing insight into the current and forecast cyclone evolution and potential threat and forecast uncertainty given by numerical models. An objectively defined continuum of cyclone phase space is illustrated here to address this issue. The two parameters chosen to define cyclone phase here are thermal asymmetry and thermal wind magnitude. While these are not the only parameters on which to produce a phase space, they were found to provide a physically insightful description of the full range of synoptic-scale cyclones." A very important characteristic which indicates the type of cyclone and its future evolution is its frontal nature (or lack of). Indeed, whether or not a given cyclone is frontal in nature is one of the most important parameters used by TPC/NHC to determine whether or not to classify a system as tropical or subtropical. The basic operational definitions of those categories of cyclones state up front that a system must be non-frontal to qualify as a tropical or subtropical cyclone. The cyclone phase space technique defines the frontal nature as the storm-motion-relative 900-600 hPa thickness symmetry across the cyclone within a 500-km radius--denoted by the symbol "B". The 500-km radius was chosen to be consistent with the average radius over which cyclonic, convergent inflow has been observed for tropical cyclones, and the use of a layer-average thickness makes the parameter resistant to short-term fluctuations in temperature resulting from transient convective activity. The areal mean of the layer-average thickness is computed for the right and left semicircles of the cyclone (with respect to its motion vector), and the value for the left semicircle subtracted from the right. This definition of B successfully distinguishes asymmetric frontal zones from symmetric local extrema of temperature associated with tropical cyclones. A value of B near zero therefore implies thermal symmetry (non-frontality) while higher positive values of B indicate increasing thermal asymmetry (frontal nature). A hemispheric flag (+1 for the Northern Hemisphere, -1 for the Southern Hemisphere) is multiplied times the right-minus-left delta thickness to keep the sign of B consistent in both hemispheres. The second important characteristic used to determine the type of cyclone is whether it is cold-core or warm-core. This property can be distinguished by examining the magnitude of the cyclone isobaric height gradient within a 500-km radius of the surface cyclone center, proportional to the geostrophic wind magnitude. If this quantity increases with height, the system is cold-core; a decrease with height implies a warm-core system. This fundamental difference of thermal wind structure between tropical and extratropical cyclones was exploited to diagnose the cold vs warm-core cyclone evolution. The second cyclone phase parameter is defined as the vertical derivative of this horizontal height gradient (within a 500-km radius of the surface center) over the 900-600 hPa layer, denoted (here) by the symbol "-VT(L)". The third cyclone phase parameter is the same quantity but for the 600-300 hPa layer ("-VT(U)"). Positive values of -VT indicate a warm-core cyclone within the layer while negative values indicate a cold-core cyclone. A tropical cyclone, which exhibits a warm-core over a deep layer, will yield positive values for both -VT(L) and -VT(U) with the former having the greater magnitude. Conversely, for a cold-core extratropical cyclone, both thermal wind parameters are necessarily negative with -VT(U) having the greater magnitude. However, some types of cyclones (e.g., subtropical cyclones, certain hybrids, and warm-front seclusion cyclones) may have a sign of -VT(L) that is different from -VT(U), i.e., shallow warm cores with colder air aloft. The three diagnostics (B, -VT(L), and -VT(U)) define the three- dimensional cyclone phase space, but since a trajectory through a cube is difficult to visualize, the phase space is presented using two cross-sections: B vs -VT(L) and -VT(U) vs -VT(L). Each cross- section thus divides into four quadrants. Some examples of the types of cyclones that fit into each include: 1. Cross-section of B vs -VT(L) Cold-core/Frontal Developing/mature extratropical cyclones Extratropically transitioned TCs Cold-core/Non-frontal Occluded extratropical cyclones Some subtropical cyclones (or neutral core) Warm-core/Frontal Warm-seclusions and some hybrids Extratropically transitioning TCs Warm-core/Non-frontal Tropical and some subtropical cyclones 2. Cross-section of -VT(U) vs -VT(L) Upper cold/Lower cold Extratropical cyclones Extratropically transitioned TCs Upper cold/Lower warm Warm-seclusions and some hybrids Most subtropical cyclones Upper warm/Lower warm Tropical cyclones I've described things about as completely as possible without the aid of graphics. However, fortunately, Bob and Jenni have a website devoted to the cyclone phase space. Thorough descriptions of the parameters are included with illustrative diagrams, and examples of the cyclone phase space, including animations made with various models, are available for many, many historical cyclones of various types. A very important feature of the website are the near-realtime phase space displays of operational analyses and forecasts for eight global and regional models. The web user has the ability to intercompare these for each storm that evolves during the forecast period, and a "phase space consensus" of all these model storms helps guide the user as to their similarity in structural evolution. It should be pointed out that the inputs to the cyclone phase space procedure come from various model analyses and forecasts--not from actual data that might have been gathered in and around a given cyclone (although that is planned for the near future). Bob and Jenni are currently working on an attempt to produce phase diagrams based upon actual observations from satellite imagery as well as a comprehensive study of subtropical cyclones that includes a phase space analysis for defining the storm phase. The realtime phase diagrams have been used experimentally and in some cases operationally by TPC/NHC and the Canadian Hurricane Centre since September, 2001, with considerable success. Hopefully, their use by other forecasting agencies will expand. Interesting persons are strongly encouraged to visit the Penn State website at the following URL: ************************************************************************* ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for August: 3 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: 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 reports on Tropical Storms Cristobal and Dolly were written by Kevin Boyle of Stoke-on-Trent, UK. A special thanks to Kevin for writing the summaries for those cyclones. Atlantic Tropical Activity for August ------------------------------------- Tropical cyclone activity in the month of August was somewhat below normal for the second consecutive year. Three named storms developed (the 1950-2001 average is 2.65), but as was the case in 2001, none of the tropical storms reached hurricane intensity. The average number of hurricanes and intense hurricanes forming during August is 1.52 and 0.58, respectively. Tropical activity in August, 2002, bore some resemblance to that of August, 2001, when three tropical storms also developed. Of the three 2001 cyclones, two formed in the tropics from disturbances of African origin while one formed in the Gulf of Mexico of non-tropical origin. This year, two storms formed in higher latitudes, both spawned by the same trough of low pressure, while one formed from a tropical wave in the eastern Atlantic. Another similarity was that the first storm of the month in both seasons (Barry in 2001, Bertha in 2002) made landfall along the U. S. Gulf Coast. However, the 2002 storms were all weaker than their 2001 counterparts. All three of the 2001 August storms peaked at 60 kts, just shy of hurricane intensity while none of the 2002 systems became that strong--Dolly was the strongest at 55 kts. Also, Tropical Storm Barry of 2001 made landfall on the Florida Panhandle almost at hurricane intensity while Bertha was barely defensible as a tropical storm when it made landfall in southeastern Louisiana. Tropical Storm Cristobal formed off the southeastern U. S. coast in the same trough which had spawned Bertha in the Gulf of Mexico but moved away from the coast, soon merging with a frontal zone. Late in the month Tropical Storm Dolly formed southwest of the Cape Verde Islands, and at one point appeared quite well-organized and was forecast to increase to hurricane intensity. However, dry air and unfavorable shear took their toll on the storm, and after struggling for several days, Dolly turned northward and dissipated northeast of the Lesser Antilles. TROPICAL STORM BERTHA (TC-02) 4 - 9 August ----------------------------------------- A. Storm Origins ---------------- Bertha was a short-lived, minimal tropical storm which formed just off the southeastern Louisiana coast and moved inland and weakened without much ado within 24 hours. The system then spent a few days drifting around over south-central Louisiana, bringing heavy rains which amounted to nearly 200 mm in some localities. On 2 August a trough of low pressure extended from the north-central Gulf of Mexico across the Florida Peninsula and into the Atlantic for several hundred miles. Thunderstorm activity was disorganized, but pressures in the northern Gulf had fallen some since the previous day and conditions were not all that unfavorable for development. There was little change in the system during the next day, but during the morning of 4 August, satellite and radar observations indicated that the broad low-pressure area in the Gulf had become better organized. A Special Tropical Disturbance State- ment noting this was issued at 1730 UTC, but the system was forecast to drift west-northwestward without significant strengthening. B. Track and Intensity History ------------------------------ As the afternoon of 4 August progressed, visible satellite imagery and radar indicated that the circulation pattern had become well-defined enough to classify the system as a tropical depression. Therefore, advisories on Tropical Depression 02 were begun at 2100 UTC, placing the broad center about 75 nm south-southeast of Biloxi, Mississippi. The MSW was estimated at 25 kts and was forecast to increase to only 30 kts by the time the depression made landfall in southeastern Louisiana. Tropical weather systems, however, are known for surprises! A reconnaissance mission into the depression at 04/2312 UTC found 1500 m flight-level winds of 47 kts and a CP of 1009 mb. Also, the South Biloxi buoy reported 10-min avg winds of 33 kts, gusting to 41 kts, at about the same time. Therefore, TD-02 was upgraded to Tropical Storm Bertha in a special advisory at 04/2330 UTC. Bertha was then centered approximately 55 nm south-southeast of Gulfport, Mississippi, or about 65 nm southeast of New Orleans, moving northwestward at 6 kts with the MSW estimated at 35 kts. Tropical storm warnings were issued for portions of the Mississippi and southeast Louisiana coasts. The upper-level outflow pattern over Bertha had improved significantly during the day, although convective cloud tops were beginning to warm. Doppler radars at Slidell, Louisiana, and Mobile, Alabama, indicated decent banding on the north side of the circulation with occasional Doppler velocities of 35-50 kts between 1200 and 2400 meters elevation. Bertha's center was very near the southeast Louisiana coast about 40 nm southeast of New Orleans by 0300 UTC on 5 August. Some strong convective cells had redeveloped near and northeast of the center, and the South Biloxi Buoy had recently reported 10-min avg winds of 32 kts, gusting to 35 kts, so the MSW of 35 kts was maintained for the 0300 UTC advisory. The center of Tropical Storm Bertha moved inland over the swampy coast- line of southeast Louisiana during the early morning hours of the 5th and by 0900 UTC was located about 32 km south-southeast of New Orleans. Doppler radar data still indicated some spots of tropical storm force winds at 300 m and deep convection had increased over the eastern portion of the circulation, so the MSW remained at 35 kts due to the possibility of tropical storm force winds at the surface in squalls. Bertha was downgraded to a tropical depression in an intermediate advisory at 1200 UTC with the poorly-defined center located near New Orleans. Winds had decreased to 30 kts with higher gusts in a few squalls east of the center. By 1500 UTC the weakening depression was centered about 90 km north-northwest of the Crescent City with winds of only 25 kts, and NHC issued their final advisory on Bertha. The Hydrometeorological Prediction Center (HPC) in Camp Springs, Maryland, began issuing storm summaries for the remnants of Bertha beginning at 05/2100 UTC. The weak LOW spent the next couple of days moving very slowly in a general westward direction across southern Louisiana, passing very near Baton Rouge around 0900 UTC on the 6th. HPC issued their final summary on the system at 0900 UTC on 7 August. The center of the weak LOW had moved southwestward and was located near the coast of central Louisiana about 95 km south of New Iberia. The LOW continued to track west-southwestward over Gulf waters and its convective organization gradually improved. At 2100 UTC NHC re-initiated advisories on Tropical Depression Bertha, placing the center about 80 nm east-southeast of Galveston, Texas. Radar estimates from Houston and Lake Charles indicated winds to 35 kts aloft--these were adjusted to 25 kts at the surface. The depression continued to move west-southwestward across the northwestern Gulf of Mexico but did not intensify further. Convection would occasionally develop but never became well-organized nor established near the center. A U. S. Air Force reconnaissance plane investigated the system during the afternoon of the 8th and found a very poorly-defined circulation with gusty winds in a few thunderstorms. During the evening of 8 August satellite and radar imagery indicated that new convection had developed near a well- defined mid-level circulation located about 35 nm northeast of the alleged LLCC in an elongated surface trough. This led to a slight relocation of the reported center in the event that a new center formed near the developing convection. Bertha's MSW remained at 25 kts until the system made landfall on the Texas coast about 100 km south of Corpus Christi around 0900 UTC on the 9th. NHC issued their final advisory on Bertha at 1500 UTC, once more turning the responsibility for issuing summaries over to HPC. Only one storm summary was issued by HPC, at 09/2100 UTC. The remnants of Bertha were then located about 30 km east-southeast of Laredo, Texas, moving west-northwestward at about 9 kts. The maximum winds associated with the system were only about 13 kts. C. Meteorological Observations ------------------------------ Bertha brought fairly heavy rains to portions of the Gulf Coast. Pascagoula, Mississippi, recorded 175 mm in the 30 hours ending at 05/1200 UTC. Van Cleave, Mississippi, netted 107 mm in the same 30-hour period, while a location in Slidell, Louisiana, recorded 91 mm. Destin and Pensacola, Florida, each recorded storm totals of 70 mm. A station identified as Pascagoula-Lott, Mississippi, recorded 181 mm in the 24 hours ending at 06/0000 UTC. McComb-Pike County, Mississippi, netted 114 mm in the 24 hours ending at 06/1200 UTC with 77 mm falling in the next 12 hours. For the 24 hours ending at 06/1200 UTC, the following amounts were recorded: Angie, Louisiana 103 mm Tylertown, Mississippi 136 mm Franklinton, Louisiana 190 mm Rainfall amounts in Texas were generally rather light. Corpus Christi recorded only 27 mm in a 30-hour period ending at 09/1800 UTC. Rockport and Alice recorded 23 mm and 21 mm, respectively, during the same period. D. Damage and Casualties ------------------------ There was some minor damage due to flooding in coastal areas of Louisiana and Mississippi, and there was one fatality attributed to Bertha--a man drowned in heavy surf caused by the storm in Northwest Florida. (Report written by Gary Padgett) TROPICAL STORM CRISTOBAL (TC-03) 5 - 8 August -------------------------------------------- A. Storm Origins ---------------- Tropical Storm Cristobal formed from a trough of low-pressure covering the northern Gulf of Mexico and extending across Florida into the western Atlantic. This trough also spawned Tropical Storm Bertha in the Gulf of Mexico. TPC/NHC issued statements on the trough in Tropical Weather Outlooks (TWO) beginning at 0930 UTC, 2 August. These statements continued to be issued for the next couple of days until at 1530 UTC on the 4th, the TWO mentioned a weak area of low pressure near the South Carolina coast that was destined to become Cristobal. The LOW was weak and development was not expected, but during the afternoon thunderstorm activity increased. Associated convection gradually became better organised and TPC/NHC issued the first advisory on Tropical Depression Three at 2100 UTC, 5 August, based on satellite, radar and aircraft reports. A Hurricane Hunter aircraft reported a central pressure of 1008 mb and flight-level winds of 33 kts in the southeast quadrant. The depression was centred approximately 135 nm south-southeast of Wilmington, North Carolina, moving east-southeastward at 5 kts. Satellite images showed that the LLCC was tucked in near a ragged CDO (cloud tops to minus 70 C) with some outer banding in the southeastern semicircle. The tropical cyclone was initially moving east-southeastward south of the mid-latitude westerly wind belt and northeast of an anticyclone over Florida. TD Three was located in a zone of unfavourable northerly shearing conditions which it endured throughout its lifetime. The shear pushed the associated deep convection to the south or southwest of the exposed LLCC. Despite the shearing and the adverse effects of a strong cold front digging southward into the area, a reconnaissance flight into the system during the late afternoon of 6 August found a pressure of 999 mb and flight-level winds of 48 to 52 kts between 1500 and 3000 metres. NHC released a special advisory at 06/2330 UTC upgrading TD Three to Tropical Storm Cristobal (Spanish for 'Christopher'). Cristobal's centre was located about 290 nm east of Jacksonville, Florida, drifting slowly southward. The MSW was estimated at 40 kts. B. Track and Intensity History ------------------------------ Cristobal continued its slow and erratic southward push in the weak northerly steering flow. Convection continued to be sheared toward the southern portions of the circulation. On 7 August Cristobal began to resemble a frontal LOW on satellite images. It still retained a vigorous circulation, however, with most of the convection contained in a curved band to the south of the centre. Parts of the cloud-mass affected the northwestern Bahamas during this time. Data from a recon- naissance aircraft indicated that Cristobal was still a 40-kt tropical storm (its peak intensity) with a minimum pressure of 1000 mb. The storm's motion, however, had changed to a slow eastward crawl as a large mid to upper-level trough began to move off the US east coast. Despite this, Cristobal appeared a little better organised in satellite images early on the 8th as new, deep convection developed in the eastern and southern quadrants. However, this rejuvenation was for a short time only. The approaching trough began to finally push the weakening cyclone northeastward away from the United States. The final advisory was issued by TPC/NHC at 2100 UTC on 8 August when a reconnaissance aircraft dispatched to investigate the health of Cristobal found that it was rapidly becoming extratropical and merging with a frontal zone. This final advisory placed the centre of Cristobal about 325 nm southeast of Cape Hatteras, moving northeastward at 15 kts. The remnant LOW was subsequently tracked across the Atlantic, passing near southeastern Newfoundland around 10/0600 UTC and to the northwest of the British Isles on 12-13 August, and was last seen heading toward the Arctic east of Greenland on the 14th as it was filling. C. Damage and Casualties ------------------------ There are no known casualties nor damage resulting from Tropical Storm Cristobal. (Report written by Kevin Boyle) TROPICAL STORM DOLLY (TC-04) 29 August - 4 September ------------------------------------------- A. Storm Origins ---------------- The tropical wave that spawned Dolly crossed the coast of Africa on 26 August. TPC/NHC's Tropical Weather Outlooks (TWO) first mentioned the system at 2130 UTC on 27 August when it was located several hundred miles south of the Cape Verde Islands. Some potential for slow development was noted as the system moved westward at 17 to 23 kts well to the south of the Cape Verdes. The TWO at 1530 UTC on the 28th indicated that a tropical depression was possibly forming about 375 nm south-southwest of the Capes Verdes. During the evening of the 28th convective activity became more concentrated, and the first advisory on Tropical Depression Four was issued by NHC at 1500 UTC on 29 August when satellite images indicated that the system had become better organised. The depression was then located roughly 550 nm southwest of the Cape Verde Islands. The cyclone displayed some banding features and very deep convection south of the centre, resulting in T-numbers of 2.0 from both TAFB and SAB. At this time TD Four was located over warm water and within a light wind shear environment. A mid-level subtropical ridge to the north of the tropical cyclone was forecast to provide a west to west- northwest steering flow for the next couple of days. The intensity was upgraded to 35 kts on the next advisory at 2100 UTC, 29 August, and the system was named Dolly--the fourth tropical storm of the 2002 season. B. Track and Intensity History ------------------------------ Tropical Storm Dolly exhibited well-defined curved bands and the outflow was fair in all quadrants. The centre of the storm was not well- established at this time and was embedded within a larger circulation. As time went by Dolly began to look more impressive with a large area of cold convective tops forming in a loose band over the western semi- circle. Maximum winds on the 30/0300 UTC advisory were raised to 40 kts based on CI estimates of 45 kts from SAB, 35 kts from TAFB, and 30 kts from AFWA. Outflow was good in all directions except eastward. There was uncertainty in fixing the LLCC with infrared-based fixes a little to the south and QuikScat and SSM/I data suggesting an elongated centre a little further north. The cloud pattern of Dolly took on a distorted appearance on the western side of the circulation but this did not affect the cold and persistent CDO. Dolly's future as a tropical cyclone depended on how far south of the unfavourable upper-level westerlies north of 15N it would remain. In the meantime Dolly continued to strengthen with winds upped to 55 kts on the 30/1500 UTC advisory. This turned out to be the peak intensity. The cyclone was then located approximately 775 nm south- west of the Cape Verdes. Outflow was excellent at this time with the centre embedded in a large area of deep convection. Later in the day though, convection began to decrease and the cloud pattern became more elongated. Tropical Storm Dolly, however, still had not moved into the hostile shear environment and it was unclear why it had begun to weaken. One possibility advanced was that dry Saharan air being sucked into the system was the culprit. A SSM/I pass at 2055 UTC on 30 August revealed a completely exposed centre, but a later pass (at 30/2339 UTC) showed a new burst of convection to the west or southwest of the LLCC. However, the outflow centre was offset to the southwest of the LLCC, suggesting that the environment was becoming less favourable. The SSM/I data showed the centre to be located further north and east than had been estimated. Dolly remained south of the low to mid-level ridge, and by 31/0900 UTC was moving west-northwestward at 17 kts as it headed toward a weakness in the ridge near 60W. Dolly's intensity had been nudged downward by 5 kts on each advisory following its peak of 55 kts, and by 31/1500 UTC the MSW had reached minimal tropical storm intensity of 35 kts. The storm had been producing deep convective bursts during the night of 30 August. This bursting pattern continued, but Dolly was in poor shape during the 31st as it struggled to maintain minimal tropical storm strength. By 0300 UTC on 1 September the cyclone had begun to feel the effects of the upper-level southwesterlies, although it still retained deep convection which was elongated northeastward/ southwestward. Outflow was better to the east of the system on the side away from the shearing southwesterlies. The warning intensity was upped a bit to 40 kts at 2100 UTC based on a blend of Dvorak CI estimates of 35 kts from TAFB and 45 kts from SAB. Deep convection had developed just north or over the LLCC and outflow was good everywhere. The strong mid to upper-level trough located north of the Lesser Antilles gradually forced Dolly on a northward path, and despite the recent convective buildup, the storm still struggled to maintain an intensity of 40 kts. Deep convection had moved to the southwest of the LLCC by 0300 UTC, 2 September. The MSW was notched up a little more to 45 kts at 1500 UTC as deep convection had moved over the LLCC. Dolly was beginning to look impressive again, but by 2100 UTC the LLCC had become fully-exposed once more. Southwesterly vertical wind shear and dry air intrusion were making a serious impact and the MSW was lowered back to 40 kts. Intermittent bursts of convection continued to occur over the system although the centre remained exposed. At 0900 UTC on 3 September the MSW was bumped up to 45 kts again based on CI estimates of 45 kts from TAFB and SAB. Dolly at this time was located about 450 nm east- northeast of the island of Guadeloupe--this was the westernmost point of its track. Visible satellite images on the morning of the 3rd showed that the centre of Dolly had reformed under the convection to the east. The MSW remained at 45 kts and Dolly's convection fluctuated as the storm continued northward. The intensity was downgraded to 35 kts at 04/0900 UTC, based on CI estimates of 35 kts from all three satellite agencies, and Dolly continued moving northward with its LLCC exposed to the south- west of its main convection and banding features. A strong mid to upper-level trough moved eastward over Dolly, completely stripping away the remaining convection. The last advisory on Dolly from NHC was issued at 1500 UTC on 4 September and downgraded the system to a dissipating swirl of clouds, located approximately 850 nm southeast of Bermuda. The remnants of Dolly continued to move northward and on the 5th interacted with a broad trough of low pressure about 800 nm east of Bermuda. Shower activity had increased and slow redevelopment was considered a possibility, but this failed to materialise. C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Tropical Storm Dolly. (Report written by Kevin Boyle) ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for August: 1 tropical depression 2 tropical storms 3 hurricanes ** ** - one of these crossed the International Dateline and became a typhoon in the Northwest Pacific basin Northeast Pacific Tropical Activity for August ---------------------------------------------- The Northeast Pacific basin became quite active during August. Five named storms formed--three east of 140W in the Eastern North Pacific proper, and two west of 140W in the Central North Pacific. The August averages for the whole basin (1971-2001) are 3.94 tropical storms, 2.39 hurricanes, and 1.10 intense hurricanes. Hurricanes Fausto and Hernan in the Eastern Pacific became intense with Hernan becoming the second Saffir/Simpson Category 5 hurricane of the year. Hurricane Ele, which formed in the Central Pacific, also became intense, reaching Category 3 intensity before crossing the International Dateline into the Northwest Pacific basin. Ele continued as a typhoon/tropical storm west of the Dateline until the 10th of September. In addition to the hurricanes, Tropical Storms Alika and Genevieve formed late in the month but failed to reach hurricane intensity. In addition to the named storms, there was one short-lived tropical depression tracked. Tropical Depression 07E formed on 6 August about 825 nm southwest of Cabo San Lucas on the tip of the Baja California Peninsula. The depression formed east of a strong mid to upper-level trough in an environment of southwesterly shear. TD-07E was forecast to become a minimal tropical storm at best, but the winds remained at 30 kts. By late on 7 August the system was beginning to move over cooler SSTs, and with the unrelenting shear, began to dissipate. The final advisory from TPC/NHC at 08/0300 UTC placed the weakening center approximately 925 nm west-southwest of Cabo San Lucas. The summaries of Hurricanes Fausto and Hernan and Tropical Storm Genevieve were written by John Wallace of San Antonio, Texas. A special thanks to John for his assistance. HURRICANE FAUSTO (TC-08E) 21 August - 3 September ------------------------------------------- A. Storm Origins ---------------- Hurricane Fausto originated from a tropical wave that left the African coast on 11 August, tracked uneventfully across the Atlantic basin, and entered the Northeast Pacific on the 17th (1), blossoming that same day. By the 19th there were definite signs of cyclonic organization, and the disturbance strengthened quickly late on the 20th. The NHC issued the first warning on Tropical Depression Eight-E at 1700 UTC on 21 August, located approximately 425 nm south-southwest of Manzanillo, Mexico. Eight-E's formation ended an unusually long "drought" in what is usually the peak of the NEP season, being the first tropical storm to form since Hurricane Elida formed nearly a month earlier. B. Track and Intensity History ------------------------------ The depression became Tropical Storm Fausto on the next advisory (at 2100 UTC on 21 August) as it tracked westward. Highly favorable upper- level conditions and warm SSTs presaged another possible monster for the NEP basin, and Fausto delivered. After 0300 UTC on the 22nd the storm deepened at a steady millibar per hour, reaching hurricane status at 2100 UTC when located about 575 nm south-southwest of Cabo San Lucas. Upon its upgrade, the storm turned west-northwestward and embarked on a track that was remarkably consistent, even for the NEP. Fausto's MSW broke 100 kts late on the 23rd, and at 1500 UTC on 24 August reached its peak MSW of 125 kts with an associated minimum CP of 935 mb. The center of the Category 4 hurricane was then located roughly 800 nm southwest of Cabo San Lucas. Fausto maintained its peak intensity for a respectable 18 hours before weakening rapidly as it crossed into cooler SSTs. Fausto's MSW dropped below 100 kts on the 25th, and by the following day it was a tropical storm, being downgraded at 26/1500 UTC when located approximately 1300 nm east of Hilo, Hawaii. On the 27th the cyclone weakened to a tropical depression and tracked past 140W into the Central Pacific Hurricane Center's AOR. The CPHC issued the final advisory on Tropical Depression Fausto at 0900 UTC on 28 August, placing the weak center about 800 nm east-northeast of Hilo. The final advisory is usually the end of the story, but Fausto refused to die. The vortex remained poorly-organized on the 28th as it continued its stubborn west-northwesterly track north of the Hawaiian Islands. Its circulation was slightly more defined the following day, though it was still completely devoid of deep convection. On the 30th, however, the vortex experienced a convective rejuvenation, and it held together remarkably well over the next two days. On 1 September, deep convection redeveloped over the center and advisories were re-initiated on Tropical Depression Fausto at 2100 UTC. Fausto's center was then located about 950 nm northwest of Honolulu. Even at its re-upgrade, Fausto remained on a steady west-northwestward track, and its organization was uncanny for a tropical cyclone at its latitude in the Central North Pacific. The regenerated depression was smaller than its earlier incarnation, and of arguable midget status. Early on the 2nd Fausto at last turned due north and accelerated in the flow ahead of an approaching trough. Its organization and convection actually improved as it merged with a frontal zone early on the 3rd; whether this was due to extratropical transition is open to debate. Water vapor imagery showed no indication of dry air intrusion into the system, and Fausto looked tropical right up until its second final advisory at 0300 UTC on 3 September when it was centered approximately 975 nm north-northeast of Midway. Fausto's remnant--tropical or otherwise--became indefinable after 1200 UTC as it crossed the Aleutian chain. (Editor's Note: It should be mentioned that some CI estimates of 35 kts--primarily from SAB--were made during Fausto's "second wind", suggesting that the system was flirting with tropical storm intensity.) Fausto's rebirth was highly unusual. Though Guillermo's (1997) regeneration was more dramatic, it did not remain tropical to as high a latitude as Fausto did. Archived imagery of SSTs from OTIS (Optimum Thermal Interpolation System), courtesy of the Fleet Numerical Meteor- ology and Oceanography Center (2), strongly suggest that warm SST anomalies in the far North Pacific were responsible. These anomalies were not due to El Nino, contrary to widespread popular misconception in 1997. C. Damage and Casualties ------------------------ No casualties or damages are known to have resulted from Hurricane Fausto. D. References ------------- (1) NHC, August summary for Northeast Pacific, 2002. (2) (Report written by John Wallace) TROPICAL STORM ALIKA (TC-01C) 22 - 28 August ---------------------------------------- A. Storm Origins ---------------- Tropical Storm Alika was the first tropical cyclone to actually reach tropical storm intensity in the Central North Pacific (between longitudes 140W and 180) in slightly over two years, the last being Tropical Storm Wene in August, 2000. A Tropical Weather Outlook from TPC/NHC during the evening of 20 August noted that showers and thunderstorms associated with a westward-moving tropical wave about 1500 nm east-southeast of the Hawaiian Islands had become more concentrated and that there was a potential for some development over the next few days. The system continued westward on 21 August with little change in organization, moving into the jurisdiction of the Central Pacific Hurricane Center (CPHC) in Honolulu. A Tropical Weather Outlook from the CPHC early on 22 August noted that the disturbance appeared to be gathering strength. The first advisory on Tropical Depression 01C was issued by CPHC at 2100 UTC on 22 August, placing the center about 900 nm southeast of Hilo, Hawaii. The depression was in an environment of significant shearing with the deep convection a full degree west and southwest of the exposed LLCC. The initial advisory did not call for the depression to strengthen into a tropical storm during the 72-hour forecast period. However, no sooner had the system been upgraded to a tropical depression than it appeared to be falling apart. Convection decreased dramatically, even though a small area of thunderstorms with warmer tops had formed over the circulation center. Indeed, the CPHC forecasters were tempted to discontinue advisories, but since the SHIFOR model was indicating eventual strengthening, depression status was maintained. A mid and upper-level circulation center was noted about 90 nm southwest of the LLCC around 23/0900 UTC. But at 23/1500 UTC there was another turn- around. Deep convection had blossomed dramatically almost over the assumed LLCC (even though the aforementioned mid-level circulation center was still located well to the southwest). TD-01C continued moving westward at a low latitude and very, very slowly became better organized. The 24/0300 UTC advisory noted that vertical shear had diminished and that the LLCC appeared to be very close to the deepest convection. Also, anticyclonic outflow appeared to be developing over the LLCC. Development was somewhat hindered due to competing convective clusters in the vicinity, mainly to the west. The 24/0900 UTC advisory indicated that a possible Fujiwhara interaction might occur with a disturbance located to the west (pre-Ele). But since vertical shear was minimal and SSTs were warm, further development was forecast. By 0000 UTC on the 25th a well-defined, curved convective band had formed, indicating intensification beneath the CDO, and at 0300 UTC the depression was upgraded to Tropical Storm Alika (Hawaiian for Alex). Alika's center was then located approximately 500 nm south- southeast of Hilo with the MSW estimated at 40 kts. The developing disturbance about 425 nm to the west-southwest was also showing signs of strengthening, and the discussion noted that Alika's development would likely be retarded due to the effects of this disturbance. B. Track and Intensity History ------------------------------ Once having reached tropical storm intensity, Tropical Storm Alika intensified rather quickly due to a favorable environment which featured low vertical shear, warm SSTs, and an upper-level anticyclone. The "fly in the ointment" was the large cyclonic vortex to the west-southwest which ultimately became Ele. Dvorak numbers had reached a nearly unanimous 3.5 by 25/1200 UTC and Alika's MSW was upped to its peak of 55 kts at 1500 UTC. The storm was then centered roughly 400 nm south- southeast of South Point on the Big Island, moving west-northwestward at 9 kts. However, six hours later Alika had noticeably weakened--the cloud structure had diminished and the tops had warmed considerably. The MSW was brought down to 50 kts and only slow weakening was forecast since most of the intensity models sustained the storm's current strength. Alika maintained tropical storm intensity on 26 August but was in a weakening mode. The disturbance to the southwest was upgraded to TD-02C at 0600 UTC and began to "steal the show" by competing with Alika for inflow. Also, shear from an upper-level anticyclone to Alika's west had a deleterious effect on the cyclone. The MSW had been reduced to 35 kts by 26/1800 UTC and continued weakening was forecast. The 2100 UTC discussion noted that some thunderstorms had redeveloped over Alika during the night but were likely temporary and diurnal in nature. Alika was downgraded to depression status at 27/0300 UTC when located about 475 nm south-southwest of Honolulu. The LLCC had become exposed and was outracing the convection. (At the same time TC-02C to the southwest was upgraded to Tropical Storm Ele.) Alika continued to move toward the west-northwest and weaken over the next day or so. Some deep convection would occasionally fire near the LLCC, but most was displaced well to the southeast of the center. The MSW was lowered to 25 kts at 28/0000 UTC, and the final advisory on the dying cyclone was issued by CPHC at 0900 UTC. A ship at 0600 UTC just north of the center reported winds of only 20 kts with a MSLP of 1011.2 mb. The center of the depression at that time was located approximately 35 nm east-southeast of Johnston Atoll, and at 0700 UTC the island reported sustained winds of 20 kts, gusting to 25 kts, with a surface pressure of 1011.5 mb. The system was forecast to completely dissipate within the next 12 to 24 hours. C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Tropical Storm Alika. (Report written by Gary Padgett) TROPICAL STORM GENEVIEVE (TC-09E) 26 August - 1 September -------------------------------------------- A. Storm Origins ---------------- Genevieve formed hard on the heels of Fausto in the form of a convective burst that flared up southwest of the Bay of Tehuantepec on 23 August. The cyclonic disturbance changed little in organization over the following days. Late on the 25th its organization improved markedly, however, and it was upgraded to Tropical Depression Nine-E at 0300 UTC on 26 August when located roughly 420 nm southwest of Manzanillo, Mexico. The depression initially tracked westward under the influence of the same ridge that was steering Fausto. Conditions were not ideal for Nine-E, neither at the upper-levels nor at the sea surface, where the cool wake of Fausto loomed. The depression made an unusual track just south of west on the 26th and into the 27th, almost making it to tropical storm strength at 2100 UTC on the 26th before its convection weakened, continuing the stop-and-go organization pattern that had persisted from its pre-tropical cyclone stage. Even so, the system had strengthened into Tropical Storm Genevieve by the time of the next advisory at 27/0300 UTC, being located about 620 nm southwest of Manzanillo. B. Track and Intensity History ------------------------------ Its earlier difficulties aside, a TRMM pass at 1003 UTC on the 27th indicated a possible eyewall--an observation repeated in another 27/1547 UTC SSM/I pass. At 2100 UTC the MSW reached 60 kts, and the CP leveled off at 989 mb at 0300 UTC on 28 August when the cyclone was located approximately 710 nm west-southwest of Manzanillo. Genevieve's track turned northwestward as it peaked due to a trough breaking down the subtropical ridge. This same trough also induced unfavorable shear over the system. Dvorak estimates pegged hurricane intensity throughout the 28th and into the 29th, but the storm's ragged circulation led the forecasters to be conservative. The shear steadily decreased from late on the 28th onward, but this was soon offset by cooler SSTs. Genevieve held its peak MSW for a respectable day-and-a-half before weakening on the 29th, due to both cooler SSTs and once-again increasingly hostile upper-level conditions. The MSW dropped below 35 kts early on the 30th with the cyclone located about 700 nm west- southwest of Cabo San Lucas. Genevieve fired up new convection later that day, but it turned out to be a temporary sputter in the overall decline. The depression turned more westward on the 31st as it became a low-level vortex--the final advisory was issued by TPC/NHC at 0900 UTC on 1 September with the center located approximately 960 nm west of Cabo San Lucas or about 650 nm west-southwest of Punta Eugenia. The remnant vortex had completely dissipated by 4 September. C. Damage and Casualties ------------------------ No casualties or damages are known to have resulted from Tropical Storm Genevieve. D. References ------------- (1) (2) (Report written by John Wallace) HURRICANE/TYPHOON ELE (TC-02C / TY 0217) 26 August - 10 September -------------------------------------------- A. Storm Origins ---------------- The Central North Pacific (CNP) on the average sees the genesis of about one named tropical cyclone per year. However, they often seem to develop in pairs or clumps. Even as Tropical Storm Alika, the first named tropical cyclone to form in the CNP in two years, was gathering strength southeast of Hawaii, another disturbance was taking shape to the southwest that was to become the second storm of the year. The last pair of CNP storms were Upana and Wene in 2000; the pair prior to that were Oliwa and Paka in 1997. Ele was the first CNP storm to form and reach hurricane intensity east of the Dateline and maintain that strength as it moved into the NWP basin since Hurricane/Typhoon Keoni of August, 1993. Brief Hurricane Li of 1994 reached hurricane intensity just east of longitude 180, but had weakened prior to crossing the Date- line. On the other hand, Oliwa and Paka of 1997 formed as tropical storms in the CNP but did not reach hurricane intensity east of the Dateline. Both, however, became intense super typhoons in the Western North Pacific. On the afternoon of 24 August a Tropical Weather Outlook issued by the CPHC mentioned an area of disturbed weather located about 700 nm south of Honolulu, drifting slowly to the west. Any development of the system was expected to be slow. About this time, TD-01C about 435 nm to the east-northeast had just been upgraded to Tropical Storm Alika, and the 25/0300 UTC discussion on Alika noted that the two systems were likely to undergo some interaction. The westernmost disturbance was not any better organized on the 25th as it moved westward at 9-13 kts. By afternoon the system was located about 700 nm south-southwest of Kona with Alika about 415 nm south of the same point. The disturbance was perhaps becoming slightly better organized, but any further development was still forecast to be slow to occur. By 0900 UTC on 26 August the disturbance had become sufficiently organized to warrant classification as a tropical depression; hence, Tropical Depression 02C was born. The initial advisory located the center approximately 525 nm southeast of Johnston Atoll. The MSW was estimated at 25 kts and the depression was not forecast to intensify much over the next 24 hours due to its proximity to Tropical Storm Alika a few hundred miles to the east-northeast. However, TD-02C with its very broad cyclonic surface circulation soon became the dominant system, helping to hasten Alika's demise. As was the case with Alika, the first advisory did not call for intensification to tropical storm intensity during the 72-hour forecast period, but did so on the next forecast six hours later. The MSW remained at 25 kts through 27/0300 UTC when it was bumped up to 30 kts. TD-02C by that time appeared to be strengthening while Alika weakened--the cloud structure showed improved banding and convection. B. Track and Intensity History ------------------------------ TD-02C was upgraded to Tropical Storm Ele at 0900 UTC on the 27th, located about 375 nm south of Johnston Atoll. Spiral bands extended 3/4 of the way around the center, and the system appeared to have a symmetrical circulation with uniform outflow in all directions, indicating that it lay beneath an anticyclone. Ele was then moving westward at 12 kts with the MSW estimated at 40 kts. (Alika had by this time weakened into a depression.) After its upgrade to tropical storm intensity, Ele intensified rapidly to 60 kts, but then the intensification process somewhat leveled off. The 27/1500 UTC discussion alluded to a TRMM pass which had revealed a precursor to an eye in a closed heavy rainband around the center. By 28/0000 UTC Dvorak ratings had reached T4.0 so Ele was upgraded to a hurricane at 0300 UTC, located approximately 450 nm south-southwest of Johnston Atoll. The storm continued moving westward at a rather low latitude and continued to slowly strengthen. Winds were upped to 75 kts at 1200 UTC based on CI numbers of 4.5 from both SAB and the Honolulu Forecast Office (HFO). As Hurricane Ele approached the International Dateline its track became more northwesterly. The intensity remained at 75 kts until 0600 UTC on 29 August when it was upped to 90 kts based on CI estimates of 90 kts from SAB and HFO. With SSTs of 30 C in the presence of minimal vertical shear, Ele continued to intensify. By 29/1800 UTC Ele was nearing longitude 180 approximately 625 nm west-southwest of Johnston Atoll, moving northwestward at 7 kts. The MSW was increased to 100 kts in the 2100 UTC advisory and to 115 kts in CPHC's final advisory on the storm at 30/0300 UTC. The 0300 UTC discussion noted that Ele was undergoing a period of rapid intensification coincident with the re-emergence of an eye in visible imagery. The final CPHC advisory placed Ele's center almost straddling the Dateline about 675 nm west-southwest of Johnston Atoll. Ele was a large, severe hurricane with gales extending outward 150 nm from the center in all directions. Hurricane-force winds extended out 30 nm to the east and typhoon-force winds 30 nm to the west. The first JTWC warning on now-Typhoon Ele at 30/0600 UTC estimated the MSW at 105 kts. This does not represent a weakening of the storm, but a disagreement between forecasters at CPHC and JTWC. Even though the JTWC warning noted that CI estimates were 115 kts, the forecaster(s) who authored the 0600 UTC warning for some reason chose to be a little on the conservative side. Ele's JTWC-reported intensity did eventually reach 115 kts, but not for another 24 hours. The storm was centered about 930 nm south of Midway at 1200 UTC, tracking northwestward at 8 kts. The MSW remained at 105 kts--the JTWC warning stated that the intensity was based on CI estimates of 102 kts, even though SAB was estimating T6.0/6.0 at 1232 UTC. The intensity was increased to the peak of 115 kts at 31/0600 UTC with Typhoon Ele then located approximately 830 nm west-southwest of Midway. The storm had turned to a north-northwesterly track into a weakness in the mid-level ridge to the north. Typhoon Ele spent almost two weeks moving slowly northward in the Northwest Pacific basin, yet, its center never moved west of 165E. The storm moved slowly north-northwestward through around 1200 UTC on the 2nd, reaching a point about 500 nm southwest of Midway. Ele then turned to a slow north-northeastward trek for a couple of days, reaching a position approximately 300 nm west-southwest of Midway. As early as the 3rd, the forecast called for the mid-level ridge to the northwest to build back towards the northeast, resulting in a resumption of Ele's northwestward track. This in fact happened--after 04/1200 UTC the by-now weakening typhoon began to move northwestward, a motion which continued for several days. Ele reached the westernmost point of its track at 1800 UTC on 8 September when it was located roughly 1000 nm west-northwest of Midway. The storm by this time had weakened to minimal tropical storm intensity as it turned northeastward. The final JTWC warning on Ele was for a 20-kt weakening depression at 10/1200 UTC, located approximately 1100 nm northwest of Midway Island. The peak intensity for Hurricane/Typhoon Ele of 115 kts was reached three times during its long lifespan: at 0000 UTC on 30 August (per the CPHC advisory noted above), from 0600 UTC on 31 August through 0600 UTC on 1 September, and for one warning cycle at 03/0000 UTC. Except for the 01/1800 UTC warning when the MSW was dropped to 95 kts, Ele's intensity remained at 100 kts or higher for 5.25 days. The slight weakening on 1 September was apparently caused by some southwesterly shearing associated with a TUTT. Satellite CI estimates at 01/1800 UTC were 90 and 102 kts, so it's possible the MSW for 1800 UTC might be re-adjusted to 100 kts in post-storm analysis. Ele had weakened to minimal typhoon intensity by 05/0600 UTC, but the MSW was bumped back to 70 kts for a 24-hour period beginning at 06/0000 UTC. As the storm moved into higher subtropical latitudes, shear increased and the storm began to weaken in earnest. Ele was downgraded to a tropical storm at 0600 UTC on 7 September and to a depression at 1800 UTC on the 9th when located approximately 1025 nm northwest of Midway. The maximum 10-min avg MSW estimated by JMA for Ele was 90 kts from 02/0600 through 03/1800 UTC. JMA's intensity was 85 kts or higher from 1200 UTC on 30 August through 1200 UTC on 4 September. NMCC's peak 10-min avg MSW for the storm was 110 kts at 1200 UTC on 2 September. Their intensity estimate was 100 kts or greater from 02/0600 through 04/1800 UTC. The minimal central pressure estimated by JMA for the typhoon's history was 940 mb from 02/0600 through 03/1800 UTC. C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Hurricane/ Typhoon Ele. (Report written by Gary Padgett) HURRICANE HERNAN (TC-10E) 30 August - 6 September ------------------------------------------- A. Storm Origins ---------------- Hernan was the third and last member of a string of powerful hurricanes in the Northeast Pacific basin that began with Elida in July. Hernan was the second Category Five hurricane of 2002, the first time in five years that two have formed in a season. "Cat Fives" are a rare beast even in the Northeast Pacific--Hernan was only the seventh to form since somewhat accurate intensity estimates began in 1971. Coincidentally, the same number of Category Five hurricanes occurred in the Atlantic during the same time period. Only Ava of 1973 stood alone within a season--perhaps the formation of one "Cat Five" is an indication that at least one other will form later in the season. However, the fact that six of the seven hurricanes have developed since the NHC took over warning responsibility in 1988 should give us pause; perhaps a future re-analysis project will show if other very intense hurricanes are lying unnoticed in the satellite data for this basin. (Editor's Note--For the record, the seven NEP Category 5 hurricanes alluded to above are: Ava (1973), Gilma (1994), John (1994), Guillermo (1997), Linda (1997), Elida (2002), and Hernan (2002). Of course Hurricane Kenna has become the eighth. The Atlantic "Cat Fives" referred to are Anita (1977), David (1979), Allen (1980), Gilbert (1988), Hugo (1989), Andrew (1992), and Mitch (1998).) The pre-Hernan disturbance formed rapidly on 30 August in the Pacific off the southwest coast of Mexico. An almost shapeless convective mass at 0000 UTC, by 0900 UTC it was already organized enough to warrant its upgrade to Tropical Depression Ten-E about 275 nm southwest of Acapulco. The cyclone tracked west-northwestward, south of a mid-level ridge over Mexico--this track characterized the system for most of its life. B. Track and Intensity History ------------------------------ Embedded in a highly favorable environment, the depression strengthened quickly into Tropical Storm Hernan at 1500 UTC on 30 August as it paralleled the Mexican coast. Thereafter, Hernan's intensification was extremely rapid: a mere 18 hours after its christening, the cyclone had reached hurricane intensity (at 0900 UTC on 31 August). Hurricane Hernan was then located approximately 265 nm south-southwest of Manzanillo, Mexico. This intensification represented a pressure fall of roughly a millibar per hour after its upgrade. Like many aggressively- intensifying tropical cyclones, however, Hernan's growth really took off only after it reached hurricane intensity. Twelve hours after becoming a hurricane, Hernan's MSW broke 100 kts; less than a day later T-numbers peaked at 7.0, representing Hernan's peak MSW of 140 kts with an attendant central pressure estimated at 921 mb at 1500 UTC, 1 September. At this time Hernan was a large, spectacular hurricane located about 75 nm south of Socorro Island--the strongest Eastern North Pacific hurricane since the legendary Hurricane Linda of 1997 (160 kts). From its upgrade to its peak intensity, Hernan's central pressure dropped an average of 1.73 mb per hour, just below the criteria for rapid deepening. However, for a 12-hour period beginning at 2100 UTC on the 31st, extending to 0900 UTC on 1 September, the pressure fell an average of 2.58 mb per hour--well within the range for explosive deepening. Hernan maintained its peak intensity for 12 hours before a slow weakening trend began due to an eyewall replacement cycle, and late on the 2nd Hernan's winds dropped below 100 kts. The following day, cooler SSTs made the eyewall cycle something of a moot point. On the 4th an approaching trough broke down the ridge to Hernan's north, prompting a northwestward turn. The trough also induced unfavorable shear over the system and Hernan weakened into a tropical storm, being downgraded at 04/1500 UTC when located roughly 700 nm west-southwest of Cabo San Lucas. By late on the 4th the system was a denuded swirl of low clouds with only sporadic convection. Hernan decelerated the following day and weakened to a depression, caught in a col between two ridges. According to NHC discussions, the same trough that broke down the subtropical ridge failed to carry Hernan northward. Upper-level conditions briefly became more favorable on the 5th before shear once again eroded the remaining convection and decoupled the circulation. The NHC issued the final advisory on Tropical Depression Hernan at 1500 UTC on 6 September, locating the weak center approximately 800 nm west of Cabo San Lucas. The remnant vortex drifted westward and remained identifiable until the 9th. C. Damage and Casualties ------------------------ No casualties or damage are known to have resulted from Hurricane Hernan. (Report written by John Wallace) ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for August: 1 tropical depression ** 2 tropical storms ++ 3 typhoons ## 1 super typhoon ** - system was classified as a tropical depression by JTWC only ++ - one of these was treated as two separate systems, both reaching tropical storm intensity, by JTWC ## - one of these formed east of longitude 180 and moved into the Northwest Pacific basin already at typhoon intensity 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. A special thanks to Kevin Boyle of Stoke-on-Trent, UK, for all his assistance. A large portion of all the summaries except for Typhoon Phanfone were written by Kevin. Also, a big thanks to Huang Chunliang of Fuzhou City, China, (currently a student in Beijing) for sending very informative reports of meteorological observations as well as damage and casualty reports. Northwest Pacific Tropical Activity for August ---------------------------------------------- Following a very active July, tropical cyclone activity quietened down some in the Northwest Pacific basin during the early part of August, but things began to heat up around mid-month, and the latter half of the month was very active with four typhoons roaming Western Pacific waters. Two of these typhoons continued well into the month of September. Two tropical storms, Kammuri and Vongfong, formed in the South China Sea and made landfall in southern China without reaching typhoon intensity. The final typhoon of the month, Ele, was a visitor from the Central North Pacific, crossing the International Dateline on 30 August already as an intense hurricane. As a typhoon, Ele slowly wandered northward over waters in the eastern portion of the Northwest Pacific basin, lasting until the 10th of September. Since the cyclone formed and attained significant intensity east of longitude 180, it will be covered in Part 3 of the August summary along with other Northeast Pacific basin storms. The other three typhoons were remarkably similar in their areas of genesis and general tracks. Phanfone became the sixth super typhoon of 2002 per JTWC's nomenclature. The storm passed only about 24 nm north of Iwo Jima as a super typhoon while moving on a fairly steady north- westerly course which took it to just south of Honshu. There Phanfone executed an abrupt recurvature to the east-northeast and remained south of Japan. Iwo Jima really became the focal point for the August typhoons--the centers of three passed less than 70 nm from the island. Phanfone's close approach was on 16 August. On the 27th a somewhat weaker but still potent Typhoon Rusa passed about 64 nm south of the southwestern tip of the island. Rusa eventually turned north and struck the southern tip of the Korean Peninsula where it became the deadliest and most destructive typhoon to affect that region in several decades. Typhoon Sinlaku made its closest approach to Iwo Jima on 2 September when the center passed only about 29 nm south of the island's south- western tip. It was still a strong typhoon, but the weakest of the three to brush Iwo Jima. From there, Sinlaku maintained a generally westward track which took it over Okinawa and eventually into Fujian Province, China. Both Rusa and Sinlaku in their latter stages developed large eyes--the signature of the so-called "annular" typhoon. Such storms typically exhibit a very large eye surrounded by a usually symmetric ring of deep convection with little convection elsewhere. They tend to maintain a fairly static intensity for days and usually weaken slowly. There was another tropical depression tracked during August, numbered TD-17W by JTWC. The system was first noted on 3 August south-southeast of Tokyo as a very small circulation. A visible satellite picture taken at 04/2330 UTC depictes a small round CDO-feature with a well-defined circulation center partially-exposed on the west-southwestern side. Mark Lander estimated the MSW at 30-35 kts based on Dvorak shear pattern analysis. JTWC issued a TCFA for the system at 0300 UTC on 5 August followed by the first warning on TD-17W at 0600 UTC. The center was located by that time approximately 540 nm east of Tokyo, and JTWC esti- mated the MSW at only 25 kts. Six hours later the depression was centered about 600 nm east of Tokyo, tracking eastward at 11 kts. Since the system had not strengthened and was moving over cooler SSTs, JTWC did not issue any further warnings. TROPICAL STORM KAMMURI (TC-16W / STS 0212 / LAGALAG) 1 - 6 August ------------------------------------------------- Kammuri: contributed by Japan, means 'crown' Lagalag: Filipino name, is an adjective meaning 'wandering, or 'roving' A. Storm Origins ---------------- The pre-Kammuri disturbance was first noted in a STWO issued at 0000 UTC, 2 August, as an area of convection which had persisted approximately 270 nm west of Luzon in the South China Sea. Animated enhanced infrared imagery indicated that the persistent convection was displaced to the west of a weak LLCC. A 200-mb analysis revealed moderate vertical wind shear and upper-level diffluence over the area. The development potential was considered poor, but was upgraded to fair in the STWO issued at 0200 UTC. At 02/2137 UTC a QuikScat pass indicated multiple LLCCs in close proximity to each other to the west, north and northeast of Luzon. Based on this, the LLCC was relocated eastward to a position approximately 140 nm west of Luzon. The STWO at 0600 UTC on 2 August indicated that a warning would be issued shortly based on synoptic reports, and the JTWC's first warning on Tropical Depression 16W was issued at this time. (There was no TCFA for this system.) The depression was tracking west-northwestward at 7 kts at the time. A SSM/I pass at 02/1027 UTC depicted deep convection surrounding the vortex, and a banding feature which extended over the south quadrant was also noted. JMA released their first advisory at 1800 UTC on 2 August, and NMCC and HKO followed at 0000 and 0600 UTC on 3 August, respectively. The system turned northward at 03/0000 UTC under the influence of a low to mid-level ridge over the East China Sea. TD-16W accelerated to 13 kts while turning back to the west at 1200 UTC as it became less influenced by the southwesterly monsoon flow. The system was consolidating, as evidenced by animated infrared satellite imagery, although a 03/1216 UTC SSM/I pass showed that the LLCC was on the northern edge of the deep convection. At 1800 UTC on 3 August, TD-16W was upgraded to a tropical storm by JTWC, HKO and JMA with the latter agency assigning the name Kammuri. NMCC upgraded the system to tropical storm status six hours later. (Editor's Note: The origins of Kammuri are a little uncertain. There is some evidence it was related to a large monsoon gyre east of Luzon in late July/early August. An area of convection had formed north- northwest of Guam on 27 July, and this area was mentioned for several days in JTWC's STWOs as it drifted westward. By 30 July the convection was cycling around the periphery of a large circulation, or gyre, in the Philippine Sea. The situation was still pretty much the same on the 31st with the deepest convection noted on the western periphery of the gyre. On 1 August the gyre appeared to be consolidating with a banding feature possibly developing over the southern periphery. It was for the monsoon gyre circulation that PAGASA initiated warnings on Tropical Depression Lagalag at 0000 UTC on 1 August. There were a couple of significant relocations over the next 24 hours. An interim STWO issued by JTWC at 02/0000 UTC mentioned the precursor of Kammuri as a distinct area of convection, but it seems possible it was related to the gyre. PAGASA's positions for Lagalag at 0600 and 1200 UTC on 2 August were well east of JTWC's coordinates, but by the time of the final PAGASA warning at 1800 UTC, the two TCWC's center coordinates were in closer agreement. The center of TD-16W/Lagalag had moved out of PAGASA's AOR by 03/0000 UTC so no more warnings were issued by that agency.) B. Track and Intensity History ------------------------------ At 04/0000 UTC Tropical Storm Kammuri was located 85 nm south- southeast of Hong Kong, China, moving westward at 4 kts with the MSW estimated at 45 kts. This was the peak intensity of the cyclone (per JTWC's warnings). Upper-air analysis indicated that northeasterly shearing from an upper-level LOW was pushing the mid-level circulation southwest of the LLCC. By 1200 UTC shearing had relaxed, allowing the mid-level circulation to return over the LLCC. This allowed the deep convection to move over the LLCC, as evidenced by a 04/1201 UTC SSM/I pass. A surge in the southwest monsoon was pushing Kammuri on an east- northeasterly heading by this time and the cyclone started to lift out of the monsoon trough. Gradually turning to a northward heading, Kammuri approached the Chinese coast, but on a weakening trend. Kammuri made landfall with the MSW estimated at 35 kts (by JTWC) at 2200 UTC just east of Shanwei. The storm began to accelerate ahead of an approaching mid-latitude low-pressure system and was downgraded to a tropical depression at 1200 UTC, 5 August, as it moved farther inland. (HKO issued their final bulletin at 0600 UTC). The cyclone dissipated over the mountainous coastline of eastern China and its remnants linked up with a cold front. JTWC stopped issuing warnings at 05/1200 UTC and JMA did so at 1800 UT. The last agency to drop Kammuri was NMCC with the last warning issued at 1200 UTC on 6 August. (Editors Note: The Asian TCWCs considered Kammuri a more intense system than did JTWC. Both HKO and JMA were estimating the 10-min avg MSW at 50 kts at the time of landfall in China, and NMCC was even higher at 60 kts. A 60-kt 10-min avg wind would equate to a 1-min avg MSW of about 70 kts. Again, as noted above, the highest 1-min avg MSW for Kammuri reported by JTWC was 45 kts.) 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. Chunliang notes that the rainfall amounts (and damages) detailed below were not due to just Tropical Storm Kammuri alone. The weakening storm merged with a frontal trough over Southern China, and it was the combination of Kammuri and the front which caused the heavy rains and the resulting damage and casualties to the region. (1) Rainfall Reports from the Meteorological Service of Fujian In Fujian Province, one county reported rainfall amounts that exceeded 400 mm, six counties reported 300-400 mm, and 14 counties reported 200-300 mm for the 3-day period of 03/0000--06/0000Z. 05/0000--06/0000 UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Quanzhou Yongchun 284.3 ** Quanzhou Anxi 196 Quanzhou Dehua 190 Quanzhou Nan'an 189 Zhangzhou Yunxiao 185 ** The highest daily amount in the history of the station. (Another station named Hongwuyi, also located in Yongchun County, reported 315 mm during the same period--the highest daily amount in the history of that station, too.) 05/2100--06/2100 UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Xiamen Xiamen 237 Fuzhou Pingtan 155 06/0000--07/0000 UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Fuzhou Fuqing 288 Xiamen Xiamen 241 Zhangzhou Zhangpu 219 Xiamen Tong'an 203 (2) Rainfall Reports from the Meteorological Service of Guangdong 02/0000--03/0000 UTC: No amounts exceeding 100 mm 03/0000--04/0000 UTC: No amounts exceeding 100 mm 04/0000--05/0000 UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Maoming Dianbai 140.2 05/0000--06/0000Z UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Shaoguan Xinfeng 106.9 Heyuan Longchuan 105.1 Jieyang Jiexi 110.2 Jiangmen Taishan 123.8 Yunfu Yu'nan 105.0 06/0000--07/0000Z UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Shanwei Shanwei 109.0 Shanwei Haifeng 148.4 Jieyang Jieyang 275.1 Jieyang Huilai 120.6 Jieyang Puning 235.1 Jieyang Jiexi 116.2 Shantou Shantou 118.7 Shantou Chenghai 136.0 Chaozhou Chaozhou 189.1 Chaozhou Raoping 258.2 07/0000--08/0000 UTC: Cities Stations Rainfall (mm) ---------- ---------- ------------- Qingyuan Lianzhou 103.8 (3) Rainfall Reports from the Meteorological Services of Guangxi, Hunan & Jiangxi 05/0000--06/0000 UTC: Tengxian, Guangxi 129 mm Cangwu, Guangxi 129 mm Wuzhou, Guangxi 118 mm 05/2100--06/2100 UTC: Shuangfeng, Hunan 102 mm 06/0000--07/0000 UTC: Lushan, Jiangxi 147 mm 07/0000--08/0000 UTC: Yongxin, Jiangxi 146 mm Jishui, Jiangxi 134 mm Yugan, Jiangxi 115 mm Zhongshan, Guangxi 118 mm (4) Rainfall Reports from the Meteorological Service of Taiwan 03/1600--04/1900 UTC: TA-CHI-S, TAITUNG COUNTY 213 mm TA TU, PINGTUNG COUNTY 127 mm TSO YING, KAOHSIUNG COUNTY 115 mm NANSHIH, MIAOLI COUNTY 103 mm 05/1600--05/1900 UTC (3 hrs): CHENG KUNG, TAITUNG COUNTY 94 mm HSIN WEI, PINGTUNG COUNTY 77 mm TSO YING, KAOHSIUNG COUNTY 60 mm 05/1600--06/1900 UTC: TUNG HO, TAITUNG COUNTY 325 mm JEASHIAN, KAOHSIUNG COUNTY 239 mm KUAN SHAN, TAINAN COUNTY 172 mm HSIN WEI, PINGTUNG COUNTY 156 mm TSAOLING, CHIAYI COUNTY 148 mm Note: CHENG KUNG, Taiwan, recorded a daily amount of 591 mm on 5 August (local time)--a new record for the station. (5) Wind Reports In Fujian Province, Xiamen City reported a daily peak wind of 41.4 kts at 05/1954 UTC. (It was not stated if this was a peak sustained wind or gust.) On 6 August Putian City (south of Fuzhou) reported a gust of 42.8 kts. Several ships reported winds exceeding 40 kts. The highest wind given in Chunliang's report was west-southwesterly 49 kts (presumably a 10-min avg) from ship OOCL FRANCE (call sign PGNE) at 0600 UTC on 4 August, located near 20.1N, 113.9E. This equates to a 1-min mean wind of about 56 kts, and if reliable, would tend to suggest that Kammuri was slightly stronger than any of the TCWCs were reporting at that point in time. D. Damage and Casualties ------------------------ A total of 107 deaths occurred as a result of Kammuri's passage. However, most of the damage and casualties in southern China were attributed to the rain-induced flooding caused by the combination of a cold front and the remnants of the tropical cyclone. Flood damage destroyed crops, bridges, tunnels and power lines. Press reports indicate that at least 13 people were killed when Tropical Storm Kammuri moved inland across the southern Chinese province of Guangdong late on 4 August. The storm, accompanied by torrential rains, ripped through the coastal cities of Shanwei, Shantou and Lufeng in the eastern part of Guangdong Province, causing extensive damage. A great deal of crop land was flooded, and many bridges, tunnels and power lines were destroyed. Water and electricity supplies in some of the storm-hit areas were also cut off. In Wuhua County alone, 10 farmers were killed when they were swallowed by a massive landslide. In Shantou, two people were electrocuted when they were repairing power facilities amid heavy rain. Shantou International Airport was closed for more than four hours, with 10 domestic and international flights cancelled or delayed. Eight scheduled flights were delayed at the Guangzhou Baiyun Inter- national Airport, while another nine arrival flights had to be diverted to other airports near Guangzhou. Torrential rains caused 28 deaths in Guangdong while four deaths were reported in Quanzhou. In Hunan Province the death toll reached 75 persons. (1) Fuzhou Area: At 06/0306 UTC the peak of flooding passed Chengguan, Yongtai County, where the Dazhang Stream rose to a level of 34.62 m--the warning and danger levels there are 31 m and 34 m, respectively. Pingtan County recorded rains of 104 mm during the 6-hr period ending at 06/1200 UTC--a rare occurrence. According to the preliminary statistics provided by Fuzhou Flood Prevention Headquarters, some 599,900 residents were affected by the flooding brought by the torrential rain in the Fuzhou area. Direct economic losses are estimated to have been approximately 425 million yuan. (2) Quanzhou Area: As of 07/1200 UTC some 372,100 residents were affected by the flooding. Four persons died with three missing in the Quanzhou area. The direct economic losses there are estimated at 552,680,000 yuan (the number rose to 660 million several days later). The number of collapsed houses was put at 7,782. (3) Guangdong Province: Statistics (13 August) indicated that 3,317,000 residents were affected by the torrential rains. Twenty-eight persons died and 6,810 houses collapsed. Direct economic losses there are estimated at 904 million yuan. (4) Hunan Province: Statistics (12 August) indicated that 3,900,000 residents were affected by the severe flooding. Seventy-five persons died while 12,400 houses collapsed, making over 10,000 persons homeless. Direct economic losses there are estimated at 2.665 billion yuan. Also, in Jiangxi Province some 526,500 residents were adversely affected by the storm. The Hong Kong Observatory website has a comprehensive report on Tropical Storm Kammuri available. The URL is: (Report written by Kevin Boyle and Gary Padgett with significant contributions by Huang Chunliang) TROPICAL STORM VONGFONG (TC-18W & 20W / TS 0214 / MILENYO) 10 - 20 August ------------------------------------------------------- Vongfong: contributed by Macau, is the Macanese word for 'wasp', a winged insect with black and yellow stripes which delivers a painful sting Milenyo: PAGASA name, is a Tagalog word for 'millennium' (Editor's Note: As is obvious from the header above, this system was treated as two distinct tropical cyclones by JTWC. However, even the STWOs following the demise of TC-18W indicate that TC-20W's develop- ment was related to the remnants of TC-18W. Also, JMA, NMCC, CWBT, the Guangdong Regional Meteorological Centre, and the Thai Meteor- ological Department considered Vongfong (TC-20W) to be a redevelop- ment of TC-18W (named Milenyo by PAGASA). In addition, Dr. Mark Lander of the University of Guam rendered his opinion that TC-20W was a redevelopment of TC-18W, and expressed his surprise that JTWC assigned a new number. Because of the weight of all the above evidence, I decided to treat this system as one tropical cyclone, as was done in the companion cyclone tracks file dispatched earlier.) A. Tropical Storm 18W (Milenyo) ------------------------------- A STWO was issued by JTWC at 0700 UTC, 8 August, for a new area of convection that had developed approximately 130 nm west-northwest of the Republic of Palau. Animated multispectral imagery indicated that a weak, exposed, LLCC was present within the monsoon trough. A TRMM pass at 0413 UTC indicated only cycling deep convection near the LLCC. The 0000 UTC surface analysis depicted a westerly wind burst south of the LLCC, while an upper-level analysis showed good outflow aloft with moderate vertical wind shear. The development was given a fair potential due to the strength of the westerly wind burst and the LLCC. However, the development potential was downgraded to poor on the next STWO issued at 0600 UTC, 9 August. Animated multispectral imagery revealed only a weak, broad circulation in the monsoon trough, and a 09/0051 UTC SSM/I pass had depicted only weak convection. Another negative factor for intensification was the increasing vertical shear. The next STWO at 10/0100 UTC, however, upgraded the development potential to fair based on increasing convection seen in infrared imagery. While earlier visible imagery had revealed a weak, broad LLCC, the circulation was now believed to extend to mid-levels. Surface analyses indicated that the westerly wind burst continued to the south of the system. JTWC issued a TCFA for the system at 10/1400 UTC--enhanced infrared imagery indicated a partially-exposed LLCC with deep convection located to the northwest of the centre. Outflow aloft was good with favourable wind shear conditions over the region while surface convergence caused an increase in wind speeds to the west of the LLCC. Warning #1 on Tropical Depression 18W was issued by JTWC at 1800 UTC on 10 August, and by PAGASA and JMA at 11/0000 UTC. (Initial positions were: JTWC - 10.0N 131.0E, PAGASA - 10.4N 130.5E, and JMA - 10.5N 130.5E). At this time PAGASA named the system Tropical Depression Milenyo. The depression was slowly drifting south-southeastward at 4 kts at this time. A TRMM pass at 10/1710 UTC revealed that the LLCC was decoupled east of the mid-level vortex. A surface analysis showed that TD-18W/Milenyo was still part of the monsoon trough, and animated water vapour imagery and an upper-level analysis indicated point diffluence with enhanced outflow due to an upper-level cyclone centred near 22.0N, 137.5E. The system was quasi-stationary at 0000 UTC, 11 August, but soon began moving to the northwest with slow intensification. Convection tended to decrease and by 1200 UTC was still sheared to the west of the LLCC. TD-18W was upgraded to tropical storm status at 1200 UTC on 12 August based on satellite CI estimates of 35 kts and an increase in convection. (TS-18W was not assigned an international name because JMA's 10-min avg MSW remained at 30 kts.) PAGASA's peak 10-min avg MSW also was 30 kts--even though PAGASA applied a name to the depression, they did not upgrade it to tropical storm strength. At 0000 UTC on 13 August the fully-exposed LLCC of TS-18W/Milenyo was moving northwestward at 9 kts. The cyclone was then centred roughly 190 nm east-southeast of Manila. The system accelerated in a more westerly direction on 13 August, and after being downgraded to a tropical depression (by JTWC) at 0000 UTC, made landfall on Luzon at 1200 UTC. JTWC issued the final advisory on TD-18W at this time with the MSW esti- mated at 25 kts. The final position was fixed at 14.8N 120.9E. PAGASA dissipated Tropical Depression Milenyo at 14/0000 UTC near 15.0N 115.0E with the final advisory being issued. The depression moved westward at 15 kts off the coast of Luzon into the South China Sea and had decelerated to a standstill by 1200 UT. JMA was the only agency issuing warnings on the system at this time, and they issued their final bulletin at 14/1200 UTC. B. Tropical Storm Vongfong (TC-20W) ----------------------------------- JTWC continued to issue STWOs covering the remnants of former TC-18W, and at 0600 UTC, 15 August, a fair potential for redevelopment was assigned. At the same time JMA re-initiated bulletins on the system, placing the centre near 13.5N, 113.6E. In addition, HKO started issuing bulletins on the depression at 1800 UTC. JTWC followed the STWO with a TCFA at 15/0851 UTC, placing the centre of the disturbance approximately 540 nm south of Hong Kong. The system exhibited an exposed LLCC with strong winds to the south enhanced by a westerly wind burst. A 200-mb analysis depicted good diffluence aloft with weak to moderate vertical wind shear. The first warning on Tropical Depression 20W was issued at 1200 UTC with the centre located at 13.4N, 113.4E. The depression was moving northeastward at 4 kts at this time, but had slowly turned to the north by 16/1200 UTC as it once again decelerated to a slow crawl. Most of the deep convection was being displaced to the southwest of the exposed LLCC. A surge in the southwest monsoon gave TD-20W an extra boost with a subsequent increase in convection in the southwestern quadrant. The surge caused the track of the tropical cyclone to describe a loop near 15N, 113E, before beginning to drift towards the north- northwest around 0000 UTC on 18 August. (NMCC had begun issuing warnings on the depression at 17/0000 UTC since it had become a potential threat to southern China.) The system at this time was consolidating, aided by the monsoon surge. This allowed the LLCC to become less-exposed and at 0000 UTC, 18 August, TD-20W was upgraded to tropical storm status. JMA also upgraded at the same time and assigned the name Vongfong. (NMCC had upgraded the system to tropical storm status at 17/1200 UTC and HKO had done so at 1800 UTC.) Tropical Storm Vongfong, located 260 nm southwest of Hong Kong, began a northward drift in response to a low to mid-level high-pressure ridge building over the South China Sea and southeastern China. The storm continued to develop in a weaker shear environment with new convection forming over the LLCC. Vongfong reached a peak intensity of 55 kts shortly before moving inland, pushed on a north-northwesterly path by building pressures to the east. (NMCC's and HKO's peak 10-min avg MSW estimates were 60 kts and 50 kts, respectively, while JMA was lowest at 40 kts.) Severe Tropical Storm Vongfong made landfall near Wuchuan, Zhanjiang City in Guangdong Province at approximately 1240 UTC on 19 August. Vongfong weakened rapidly as it moved north-northwestward at 13 kts over China and was downgraded to a depression at 20/0000 UTC. The last warning was issued at this time by JTWC and NMCC. (JMA had released their final bulletin at 19/2100 UTC.) C. Meteorological Observations ------------------------------ Huang Chunliang has sent me many observations and reports from southern China. Some of the highlights are summarized below. (A special thanks to Chuliang for sending the information.) (1) Rainfall Reports from Guangdong Province The following rainfall totals are 24-hour totals recorded between 19/0000 and 20/0000 UTC. Only amounts exceeding 100 mm are listed. Cities Stations Rainfall (mm) ---------- ---------- ------------- Maoming Huazhou 144.9 Maoming Dianbai 105.8 Zhanjiang Zhanjiang 211.0 Zhanjiang Wuchuan 126.6 Zhanjiang Suixi 201.3 Zhanjiang Lianjiang 211.0 Zhanjiang Leizhou 132.6 Zhanjiang Xuwen 112.3 During the 24 hours ending at 21/0000 UTC, only one station recorded more than 50 mm: Cities Stations Rainfall (mm) ---------- ---------- ------------- Zhongshan Zhongshan 90.9 Following are some rainfall amounts recorded at the Zhanjiang Meteorology School for various time periods on 19 August (only amounts greater than 200 mm are given): Periods Rainfall Observations -------------------- --------------------- 19/0000--19/1200 UTC 202.6 mm 19/0000--19/1300 UTC 221.1 mm 19/0000--19/1400 UTC 221.8 mm 19/0000--19/1700 UTC 222.6 mm (2) Rainfall Reports from Hainan Province The following rainfall amounts represent 36-hour totals recorded between 18/0000 and 19/1200 UTC: City Rainfall --------- -------- Haikou 234.8 mm ** Wenchang 197.0 mm Qionghai 106.5 mm Chengmai 110.0 mm Ding'an 105.7 mm Tunchang 110.8 mm Qiongshan 209.9 mm ** - Haikou (WMO 59758) recorded a 3-day total of 240 mm on 17-19 August (3) Wind Observations from Guangdong Province The information from Chunliang did not explicitly state if these are sustained or peak gust measurements. Based on some other statements, however, I believe that they represent peak gusts. (Only those exceeding Beaufort Force 10 are given.) Time Automatic Weather Stations Wind (kts) ----------- ----------------------------------------- ---------- 19/0900 UTC Met. Village, Hailing Is., Yangjiang City 57 19/1000 UTC Genzi Town, Gaozhou City 55 19/1200 UTC Genzi Town, Gaozhou City 65 19/1300 UTC Genzi Town, Gaozhou City 70 19/1400 UTC Genzi Town, Gaozhou City 62 19/1100 UTC Zhanjiang 56 19/1200 UTC Zhanjiang 58 19/1300 UTC Zhanjiang 60 19/1100 UTC Jizhao Town, Wuchuan City 57 19/1200 UTC Jizhao Town, Wuchuan City 67 19/1300 UTC Jizhao Town, Wuchuan City 66 19/1200 UTC Wuchuan, Zhanjiang City 66 19/1300 UTC Wuchuan, Zhanjiang City 56 19/1200 UTC Dianbai, Maoming City 58 19/1300 UTC Dianbai, Maoming City 56 19/1200 UTC Zhanjiang Meteorology School 56 19/1300 UTC Zhanjiang Meteorology School 53 19/1400 UTC Zhanjiang Meteorology School 51 19/1500 UTC Gaozhou, Maoming City 62 20/0000 UTC Gaozhou, Maoming City 62 20/0000 UTC Liantang, Shenzhen City 52 (4) Miscellaneous Observations (a) Hechi (WMO 59023) in Guangxi Autonomous Region recorded 120 mm of rain for a 3-day total on 17-19 August. (b) Hong Kong (WMO 45007) recorded 81 mm of rain for a 3-day total on 17-19 August. (c) In Bobai County in Guangxi Autonomous Region, 124 mm of rain fell in a 9-hour period ending at 19/2100 UTC. (d) Lushan County, Guangxi Autonomous Region, reported a peak wind gust of 62 kts at 19/1603 UTC. (5) An Additional Wind Observation Another wind observation was obtained from near the center of Vongfong by a new advanced instrument which was installed on the top of a three-floor villa (height unknown) in a small town named Jizhaowan in the Wuchuan district of Zhanjiang City, Guangdong Province. The center of the cyclone passed around 19/1240 UTC, but 90 minutes earlier at 1110 UTC, a peak wind (presumably a gust) of 78 kts was recorded. It was on the basis of this measurement that NMCC increased the 10-min avg MSW for Vongfong to 60 kts on the 1200 UTC warning. This wind observation, if accurate, would suggest that Vongfong was very near typhoon strength at landfall. D. Damage and Casualties ------------------------ According to a preliminary survey, some 1,163,000 residents in Zhanjiang City were affected by Vongfong with 4173 houses destroyed and 12,468 partially damaged. Direct economic losses were estimated at 280 million yuan. In Maoming City 236,500 residents were affected by the storm with 956 houses collapsed. Direct economic losses were estimated at 71.8 million yuan. Later statistics indicated that 1,625,500 residents in Guangdong Province were affected by the tropical cyclone with 5600 houses destroyed. Total direct economic losses in the province were estimated at 381.7 million yuan. No casualties were reported. In Hainan Province, 2145 trees were felled by Vongfong in Haikou City, the provincial capital. The storm left more than 250 tons of rubbish for the city to clear away. Economic losses were estimated at 3.78 million yuan in Haikou. Fortunately, no casualties were reported. In the Guangxi Region, 20 counties/cities recorded rains in excess of 100 mm during the 48-hour period ending at 20/0000 UTC. The torrential rains and associated landslides were responsible for 12 deaths with another 25 injured. About 400 houses were destroyed in this region. In its first incarnation as Tropical Depression Milenyo (18W), the system dropped heavy rains in the Philippines which led to flooding and landslides. Hardest hit regions were Negros Occidental, Biliran Island, and Laguna. The death toll was placed at 15 persons with four missing and two injured. The number of families affected was estimated at 1930, or 9611 persons. Monetary estimates of the damage are not currently available. Some pictures of the flooding caused by the depression near Naga City may be found at the following URL: The Hong Kong Observatory website has a comprehensive report on Tropical Storm Vongfong available. The URL is: (Report written by Kevin Boyle with significant contributions by Huang Chunliang) SUPER TYPHOON PHANFONE (TC-19W / TY 0213) 11 - 24 August ------------------------------------------ Phanfone: contributed by Laos, means 'animal' A. Storm Origins ---------------- The sixth super typhoon of the year in the Northwest Pacific had its beginnings on 6 August in an area of convection which developed about 90 nm south of Kwajalein Atoll. A special STWO issued by JTWC at 2000 UTC noted that animated infrared imagery revealed cycling deep convection associated with a region of low-level turning, while surface synoptic reports had indicated significant pressure falls as the disturbance tracked through the Marshall Islands. A 200-mb analysis indicated weak to moderate vertical shear in the southwestern quadrant of an upper-level ridge. By the 7th, however, the focus of interest had shifted eastward to a point approximately 420 nm east of Kwajalein. Unfortunately, I am missing the STWO for 0600 UTC on 8 August, but on the 9th a disturbance was located approximately 140 nm southeast of Kwajalein. I feel fairly certain this is the same system first noted on the 6th. The disturbance lay within an extension of the monsoon trough extending from Kosrae toward the Marshall Islands. A 200-mb analysis indicated good poleward outflow due to an upper-level LOW northeast of the disturbance as well as good equatorward outflow. The development potential was upgraded to fair based on the good outflow and the approach of a westerly wind burst to the area. On the 10th the system was relocated westward to a position approximately 300 nm west of Kwajalein. A weak LLCC with cycling deep convection was evident, and with a westerly wind burst approaching, the development potential was upgraded to good and a TCFA issued at 0700 UTC. By 0000 UTC on 11 August visible imagery and a SSM/I pass revealed low-level banding and a well-organized mid-level vortex, so JTWC initiated warnings on Tropical Depression 19W. The center was located approximately 230 nm north-northeast of Pohnpei with an initial warning intensity of 25 kts. TD-19W was moving west-northwestward at 7 kts, and this motion was expected to continue as the system was guided by a low to mid-level ridge to the north. By 1800 UTC satellite CI estimates had risen to 35 kts and a 11/1443 UTC TRMM pass revealed well-developed banding, so the depression was upgraded to a 40-kt tropical storm, located about 200 nm north-northwest of Pohnpei. B. Track and Intensity History ------------------------------ Both JMA and NMCC upgraded the system to tropical storm status at 0000 UTC on the 12th with JMA assigning the name Phanfone. The storm gradually strengthened during the day with the MSW reaching 55 kts at 1200 UTC. Phanfone was still embedded in the monsoon trough with strong equatorial westerlies to the south. The cyclone's track took a north- northwesterly turn on the 12th, likely due to a weakening of the ridge to the north. At 1800 UTC Phanfone was centered approximately 340 nm north of Pohnpei, tracking northwestward at 6 kts. The system exhibited good poleward and equatorward outflow, and appeared to be consolidating with tightly-curved bands forming during the previous few hours. By 0600 UTC on 13 August Tropical Storm Phanfone had reached a position about 670 nm east-northeast of Guam and was moving north-northwestward rather quickly at 17 kts. Based on CI estimates of 55 and 65 kts, JTWC upgraded the storm to typhoon status, but animated water vapor imagery indicated that deep convection was being sheared from the northwest as an upper-level LOW to the north-northwest propagated westward. On the other hand, pole- ward outflow was being enhanced by an upper-level trough to the east- northeast. A 13/1429 UTC TRMM pass revealed the development of a banding eye feature, so the MSW was upped to 75 kts at 1800 UTC. Phanfone was then located approximately 560 nm east-northeast of Guam. The storm's motion had become more northwesterly as a mid to high-level ridge built to the north. A 13/2333 UTC SSM/I pass showed an improving banding eye feature on the northern side of the LLCC. At 1400 UTC both JMA and NMCC upgraded Phanfone to typhoon status. A shortwave trough east of the system and a near-equatorial ridge to the south continued to enhance outflow and Phanfone slowly strengthened. By 1800 UTC JTWC had upped the MSW to 90 kts with the typhoon located approximately 475 nm southeast of Iwo Jima. A 14/1510 UTC TRMM pass had depicted a banding eye with the deep convection on the northeastern side wrapping into the LLCC. The northwestward track continued as the ridge to the north held strong. Phanfone continued to strengthen as the 15th progressed, reaching 120 kts by 1200 UTC when the typhoon was centered about 220 nm east-southeast of Iwo Jima. The eye diameter had shrunk from 21 nm at 15/0000 UTC to 10 nm at 1200 UTC. Satellite CI estimates had reached 127 and 140 kts by 1800 UTC and Phanfone was upgraded to a 135-kt super typhoon--the sixth of the year--at that hour. The eye diameter had expanded to 30 nm and gales reached outward well over 200 nm in all quadrants except the southwest, reaching 250 nm in the southeastern quadrant. Super Typhoon Phanfone was then centered about 120 nm east-southeast of Iwo Jima, moving northwestward at 16 kts. The MSW of 135 kts represents the peak intensity estimated by JTWC for Phanfone. JMA's and NMCC's 10-min avg MSW estimates had reached their respective peaks of 85 kts and 100 kts at 1200 UTC. The minimum CP estimated by JMA was 940 mb at 16/0600 UTC. A slow weakening trend began on 16 August. The MSW was reduced to 130 kts at 0000 UTC, and by 0600 UTC SSM/I and visible imagery revealed a 15-nm irregular eye and rapidly weakening deep convection. (CI esti- mates, however, were still 127 and 140 kts.) The storm at this time was centered about 40 nm north-northwest of Iwo Jima, having passed only about 24 nm north of the island's northern tip around 0400 UTC. The northwestward motion had slowed to around 10-12 kts, although some wobbling of the eye resulted in a slightly more westward track for awhile. Super typhoon status was maintained through the 1200 UTC warning, but the MSW was reduced to 120 kts at 1800 UTC with Phanfone centered approximately 530 nm south of Tokyo. The observed weakening likely resulted from two causes: a dissipating poleward outflow channel and an eyewall replacement cycle. The latter was noted in the 1200 UTC warning and was nearing completion by 1800 UTC. The remarks in the 1800 UTC warning noted that a short-term intensification might ensue, but this apparently did not materialize. Typhoon Phanfone continued to trek northwestward on 17 August at around 10-12 kts, turning more to the north-northwest by around 1200 UTC. The MSW was reduced to 115 kts at 17/0000 UTC and remained there for 18 hours. The eyewall replacement cycle observed on the previous day did not result in any intensification of the storm, but perhaps helped to slow the weakening process a bit. The remarks in the 0000 UTC warning noted that the replacement eyewall's intensity had been improving over the past few hours, and the 0600 UTC warning remarked that the inner eyewall had collapsed. A 17/1042 UTC SSM/I pass depicted an eye 40 nm in diameter, and CI estimates ranged from 90 to 127 kts. At 1800 UTC JTWC lowered the MSW to 110 kts, and the intensity was reduced by 5 or 10 kts on just about every subsequent warning. The storm at that hour was located approximately 340 nm south-southwest of Tokyo, moving north- northwestward at 10 kts. A weakness in the subtropical ridge to the north of the typhoon had appeared by the 18th, and Phanfone's forward motion slowed as it approached the ridge axis. The storm underwent a very abrupt recurvature on the 18th--at 0600 UTC it was moving north-northwestward at 4 kts, but by 1200 UTC was tracking northeastward at 6 kts. The intensity fell from 105 kts at 0000 UTC to 90 kts at 1800 UTC, based on CI estimates of 77, 90 and 102 kts at the latter hour. Convection began to weaken as dry air was entrained into the storm. By 1800 UTC the eyewall had almost completely eroded in the southwestern quadrant. Typhoon Phanfone was then located roughly 255 nm south-southwest of Tokyo, moving east- northeastward at 7 kts. At 0000 UTC on 19 August JTWC judged Phanfone to have begun extratropical transition. The MSW continued to drop and by 1200 UTC the once-powerful super typhoon was reduced to minimal typhoon intensity about 160 nm south-southeast of Tokyo. A SSM/I pass at 19/1115 UTC depicted all the deep convection displaced north of the center with no convection in the southern semicircle. JTWC downgraded Phanfone to a 55-kt tropical storm at 1800 UTC when located approximately 200 nm southeast of Tokyo. JMA and NMCC also downgraded the cyclone to tropical storm status at the same time. The storm was moving east-northeastward along the northwestern periphery of the subtropical ridge and was continuing to merge with the mid-latitude westerlies. By 0600 UTC on the 20th Phanfone was located about 440 nm east of Tokyo and was racing east-northeastward at 33 kts. JTWC declared the system extratropical and issued their final warning with the MSW estimated at 50 kts. NMCC and JMA continued to classify Phanfone as a tropical cyclone through 20/1800 UTC. JMA declared the system extratropical at 21/0000 UTC when it was located roughly 750 nm northeast of Tokyo, well east of Hokkaido. The system continued moving generally northeastward as a slowly weakening extratropical gale, reaching a position near the southwestern Aleutian Islands by 24/1200 UTC when it was last referenced by JMA. C. Meteorological Observations ------------------------------ The center of Super Typhoon Phanfone's eye passed about 24 nm north of Iwo Jima's northern tip around 0400 UTC on 16 August (according to my calculations based on JTWC's coordinates). Roger Edson sent me some observations from the island as Phanfone passed by. Sustained winds (10-min avg) exceeded gale force from 15/2100 UTC through at least 16/0900 UTC. Data was missing at 1000 and 1100 UTC--at 16/1200 UTC the wind was 31 kts from the south-southwest. At 15/2225 UTC the wind was northerly 43 kts, gusting to 68 kts, and continued to increase thereafter to the peak of 57 kts at 16/0100 UTC, accompanied by gusts to 89 kts. However, the peak gust (at least near the time of the hourly observations) was 91 kts at 16/0000 UTC. At 0500 UTC the wind was southwesterly 56 kts, gusting to 76 kts. The minimum SLP was 956 mb at 16/0100 UTC. (A special thanks to Roger for sending me the observations.) D. Damage and Casualties ------------------------ No reports of damage or casualties resulting from Super Typhoon Phanfone have been received. (Report written by Gary Padgett) TYPHOON RUSA (TC-21W / TY 0215) 22 August - 1 September ------------------------------------------- Rusa: contributed by Malaysia, is a type of samber deer most commonly seen in secondary forests on gently sloping terrain A. Storm Origins ---------------- Typhoon Rusa was a classic "straight-shooter" typhoon, one which main- tains a very straight trajectory for several days. In its latter stages the storm became the most destructive and deadly typhoon to strike the Korean Peninsula in many decades. The regular STWO issued by JTWC at 0600 UTC on 19 August mentioned that an area of convection had formed approximately 300 nm east-southeast of Pohnpei. Cycling deep convection was associated with a weak LLCC, and a 200-mb analysis indicated good diffluence aloft and moderate vertical shear associated with an upper- level ridge extending along latitude 12N. On the 20th the disturbance was relocated northwestward to a point about 110 nm north of Pohnpei. A surface analysis and satellite imagery revealed a surge in the cross- equatorial southwesterlies south of the region. Again, as was the case with Phanfone, I am missing a STWO (21 August) which would shed some light on the history of the pre-Rusa disturbance. On the 22nd what I believe to be the same disturbance was located about 210 nm north-northeast of Eniwetok. (There is a slight amount of uncertainty as to whether this is the same system of 20 August since there was another disturbance on the 22nd located farther west, but the easternmost one is closer to the position of the original disturbance on the 20th.) Animated visible imagery indicated increasing convection near the LLCC with good diffluence aloft due to an upper-level LOW to the east- northeast. The development potential was upgraded to fair at 22/0600 UTC, and just three hours later a TCFA was issued, upgrading the potential for development to good. By this time a convective band was forming in the northern semicircle and beginning to wrap into the LLCC. JTWC issued the first warning on Tropical Depression 21W at 1200 UTC on 22 August, placing the center approximately 230 nm north of Eniwetok Atoll. A 22/1042 UTC SSM/I pass depicted a symmetric system with multiple rain bands wrapping into the LLCC. TD-21W was moving slowly northwestward at 5 kts, guided by a low to mid-level ridge to the north. An upper-level LOW northeast of the depression was enhancing outflow and the system steadily intensified. At 0000 UTC on the 23rd the cyclone was located about 300 nm north-northwest of Eniwetok and the track had become more west-northwesterly--a direction that it was to maintain for several days. Satellite CI estimates had reached 35 and 45 kts by 0000 UTC, so the depression was upgraded to tropical storm status by JTWC, NMCC, and JMA with the latter assigning the name Rusa. B. Track and Intensity History ------------------------------ By 1200 UTC a second upper-level LOW had developed northwest of Rusa, also enhancing outflow, and the storm was forecast to intensify rapidly over the next 48 hours. JTWC upped the MSW to 55 kts at 1800 UTC, based on CI estimates of 45 and 55 kts, and both JMA and NMCC were estimating the 10-min avg MSW at 50 kts. Rusa was then located approximately 750 nm east-northeast of Saipan. JTWC upgraded Rusa to a minimal typhoon at 24/0000 UTC when the storm was located about 690 nm east-northeast of Saipan, moving west-northwestward at 13 kts. However, the MSW remained pegged at 65 kts for 18 hours. A 24/1130 UTC TRMM pass revealed that deep convection was confined to a single feeder band surrounding the eastern and northern quadrants. The storm had moved near enough to the upper-level LOW to the northwest that it was inhibiting convective development in the western semicircle. By 1800 UTC, however, deep convection had increased near the center and CI estimates had risen to 65 and 77 kts. Based on this, JTWC upped the MSW to 70 kts with the typhoon located roughly 560 nm east-northeast of Saipan. Rusa moved steadily west-northwestward on 25 August at a speed of about 14 kts. The upper-level LOW located to the storm's east continued to enhance outflow and Rusa steadily intensified. JTWC increased the MSW by 5 kts on each advisory, reaching 90 kts at 1800 UTC based on CI estimates of 77 and 90 kts. Also at 1800 UTC, JMA upgraded Rusa to typhoon status--NMCC had done so six hours earlier. Convection had continued to increase near the center and microwave imagery around 1200 UTC had revealed a small eye feature. Rusa was centered at 1800 UTC approximately 410 nm east-southeast of Iwo Jima. JTWC increased the MSW to 100 kts at 26/0000 UTC and to the peak intensity of 115 kts six hours later as satellite intensity estimates had reached 115 kts. Satellite imagery revealed a 6-nm diameter eye surrounded by deep convection. Gales reached outward up to 140 nm in the northern semicircle and from 100-120 nm to the south while the radius of storm-force winds was estimated at 60-70 nm. The mid-level subtropical ridge to the north continued to build westward and Rusa marched steadily west-northwestward at around 10-12 kts. JTWC maintained the peak intensity of 115 kts for 24 hours. NMCC's and JMA's estimated peak 10-min avg MSW values for Rusa were 90 kts and 80 kts, respectively, and the minimum CP estimated by JMA was 950 mb. Interestingly, JMA later reported the intensity of Rusa at 80 kts when JWTC's estimated 1-min avg MSW was only 85 kts. The typhoon's center passed about 64 nm south of the southwestern tip of Iwo Jima during the afternoon of 27 August (around 0245 UTC), and by 0600 UTC was located a little less than 70 nm southwest of the island. Rusa weakened slightly on the 27th due to some dry air entrainment in the mid-levels. The storm also went through an eyewall replacement cycle, as indicated by a 27/1608 UTC TRMM pass. The MSW was lowered to 105 kts at 0600 UTC and to 90 kts six hours later, but had recovered to 95 kts by 1800 UTC based on CI estimates of 90 and 102 kts. At 1800 UTC Typhoon Rusa was located about 550 nm east of Kadena AB, Okinawa, moving west-northwestward at 13 kts. Typhoon Rusa was moving west-northwestward at 13 kts as it crossed 135E on 28 August with the MSW estimated at 95 kts. At 0000 UTC it was located approximately 470 nm east of Kadena, Okinawa. Animated multi- spectral imagery indicated a symmetric system with a 5-nm eye. Rusa had undergone an eyewall replacement cycle prior to the 0000 UTC warning. Microwave data suggested that the system might have been forming a new concentric eyewall during this time. The MSW had increased to 95 kts but a slow weakening occurred during the day. However, 28/2201 UTC and 28/2358 UTC SSM/I passes revealed that overall deep convection coverage had increased and that Rusa's wind field had expanded. At 29/0600 UTC the latest 85 GHz image indicated that the inner eyewall had collapsed with a large, 120-nm diameter symmetric outer ring visible. Typhoon Rusa had become an 'annular' typhoon--a term used to describe usually intense tropical cyclones with large diameter eyes surrounded by a fairly symmetric ring of deep convection with little deep convection elsewhere in the circulation. Annular typhoons (or hurricanes) tend to weaken slowly after reaching their peak intensity and may maintain a static intensity for several days. Rusa crossed the northern Ryukyu Islands on 28 August. The typhoon then turned to the northwest as a low-pressure system moving over eastern Russia began to erode the ridge extending across Korea into the Sea of Japan. This northward turn into the weakening ridge towards South Korea continued on the 30th when a SSM/I pass at 0000 UTC showed a large continuous ring of convection 110 nm in diameter. The MSW was still a dangerous 80 kts, and Rusa only slowly weakened to minimal typhoon intensity by the time it made landfall in South Korea at 31/0600 UTC. Even at landfall Typhoon Rusa took time to wind down and was still of minimal tropical storm intensity at 0600 UTC on 1 September when JTWC issued their final warning, placing the center over the Sea of Japan approximately 140 nm northeast of Seoul, South Korea. JTWC deemed the system extratropical at this time, and NMCC and JMA both downgraded it to tropical depression status and issued their final warnings. (It should be mentioned that all three warning agencies were classifying Rusa as a 70-kt typhoon around the time of landfall in South Korea.) C. Meteorological Observations ------------------------------ Typhoon Rusa passed very close to Amami Airport (28.4N, 129.7E) in the northern Ryukyu Islands. The lowest SLP reported was 951 mb at 29/0841 UTC and the peak sustained wind (10-min avg) recorded was 63 kts, with a maximum gust of 80 kts, at 29/0500 UTC. As early as 28/2130 UTC the wind was northerly at 37 kts, gusting to 50 kts, and at 29/1000 UTC was easterly at 32 kts. (One press report alluded to winds of 110 kts being reported in South Korea, but the location was not specified, nor was any qualifying information given such as sustained vs gusts, esti- mated vs recorded, etc.) Unfortunately, I do not have any observations from Iwo Jima during Rusa's passage near the island on 27 August. After the report on Typhoon Rusa was completed, I received some station reports from Huang Chunliang. These stations are located in the northern Ryukyu Islands north of Okinawa. (A special thanks to Chunliang for sending me the information.) I have included some of the highlights of these reports below. The MSW values are 10-min averages and the rainfall amounts represent two-day totals recorded on 29 and 30 August (local time) with a couple of exceptions annotated. Station Station Peak Minimum Rainfall Name ID Coordinates MSW (kts) Press (mb) 2-day Total ------------------------------------------------------------------------ Naze WMO 47909 28.4N, 129.5E 32 951.9 409 mm Okinoerabu WMO 47942 27.4N, 128.7E 42 971.7 136 mm Kikai Jima JMA 88851 28.3N, 129.9E 51 N/A 213 mm Yoron Jima JMA 88986 27.0N, 128.4E 45 N/A 16 mm ** Koniya JMA 88901 28.6N, 129.3E N/A N/A 177 mm ** Isen JMA 88956 27.7N, 129.0E N/A N/A 285 mm ** - These amounts are 24-hour totals for 29 August only. D. Damage and Casualties ------------------------ Typhoon Rusa was the deadliest typhoon to affect South Korea since Typhoon Sarah in 1959. The US publication, The World Almanac, lists the death toll from that disastrous typhoon at over 2000 in South Korea and Japan. According to the same source, Typhoon Gilda of 1974 left 108 persons dead in Japan and South Korea. According to reports from South Korea's anti-disaster center a total of 113 people were confirmed dead and 71 others missing as a result of Rusa's passage through the nation. One of the worst affected areas was the east coast province of Gangwon where 128 people were killed or missing. The actual number of persons confirmed dead varied among various reports--the final report from the Office for the Coordination of Humanitarian Affairs (OCHA) stated that 151 persons were confirmed dead with 33 still unaccounted for. The city of Gangneung, in Gangwon, was swamped by waist-high floods after 914 mm of rain fell in less than two days. (Other press reports quoted the amount of rainfall at various values ranging from about 870 mm to 900 mm.) Typhoon Rusa accelerated an outbreak of conjunctivitis in South Korean schools. A few days after the storm, more than 166,000 students had contracted the highly contagious viral eye disease. According to the OCHA report, the total monetary estimate of the damage wrought by Typhoon Rusa in South Korea amounted to 5.46 trillion won, equivalent to $4.21 billion US dollars. In North Korea (DPR Korea) Typhoon Rusa was also destructive. Several press reports alluded to "scores of fatalities", but the OCHA reports and other reports on the ReliefWeb Homepage did not specifically mention any deaths attributed to the storm. However, given the magnitude of the flooding, it seems likely that there would have been some loss of life. The worst affected counties were Tongchon and and Kosong, where from 300 to 510 mm of rain fell within a 5-10 hour period on 1 September. The situation was exacerbated by a tidal surge of 1.5 meters and wind gusts to 50 kts. Agricultural losses were substantial with thousands of hectares flooded, and damage to the infra- structure was great also with roads, bridges, railway lines, electricity, schools, and telephone lines being affected. The storm's remnants moved north into Russia's Far East, bringing torrential rain to Sakhalin Island. Flooding caused by the rains destroyed homes, washed away roads and cut power supplies for hours. No casualties or injuries were reported. More information on the effects of Typhoon Rusa's deadly and destructive strike on the Korean Peninsula can be found at the following URL: (Report written by Gary Padgett and Kevin Boyle) TYPHOON SINLAKU (TC-22W / TY 0216) 28 August - 8 September ------------------------------------------- Sinlaku: contributed by the Federated States of Micronesia, is the name of a legendary Kosrae goddess A. Storm Origins ---------------- Typhoon Sinlaku formed less than a week after and in the same general area as Typhoon Rusa. Like the earlier storm, Sinlaku was also a "straight-shooter", following a fairly straight course for several days. Whereas Rusa had followed a long west-northwest trajectory which took it between Okinawa and Japan and later curving northward toward its destructive rendezvous with South Korea, Sinlaku's track was more west- ward and to the south of Rusa's, taking it over Okinawa, and after a few wobbles, into Fujian Province, China. JTWC issued a special STWO at 2100 UTC on 26 August, noting that an area of convection had formed and persisted approximately 630 nm east-northeast of Saipan. A LLCC was present with cycling deep convection, and a 200-mb analysis indicated good diffluence aloft and weak to moderate vertical shear, hence, the development potential was assessed as fair. By 27/0600 UTC the system was located about 590 nm east-northeast of Saipan with a fully-exposed LLCC accompanied by cycling deep convection. A SSM/I pass at 27/2324 UTC showed some curvature in the convection south of the center, but it had not yet begun to wrap into the LLCC. By 1000 UTC on the 28th, however, a convective band was beginning to curve into the center and deep convection in general was increasing. Vertical shear was still moderate, but the potential for development was upgraded to good and a TCFA was issued, placing the center approximately 540 nm east of Saipan. Also, at 1200 UTC, JMA classified the system as a 30-kt tropical depression. The first JTWC warning on Tropical Depression 22W was issued at 1800 UTC on 28 August. The center was located approximately 510 nm east of Saipan with the MSW estimated at 25 kts. A TRMM pass at 28/1518 UTC had indicated increasing organization in the lower levels with deep convection increasing, particularly in the southern semicircle where spiral bands appeared to be forming. Satellite intensity estimates had reached 30 and 35 kts by 29/0000 UTC, so the MSW was increased to 30 kts. The LLCC was partially-exposed with deep convection primarily in the eastern semicircle. By 0600 UTC, CI estimates were 35 kts, so the depression was upgraded to a tropical storm, located about 850 nm east- southeast of Iwo Jima. NMCC and JMA also both upgraded the system to tropical storm status at 0600 UTC with JMA naming the cyclone Sinlaku. Tropical Storm Sinlaku generally moved slowly northward initially, tracking into a weakness in the subtropical ridge which had resulted from a TUTT penetrating the ridge. B. Track and Intensity History ------------------------------ The MSW was increased to 45 kts at 29/1200 UTC. The JTWC warning noted that microwave imagery had clearly indicated a developing banding eye feature. At 1800 UTC Sinlaku was located about 790 nm east-southeast of Iwo Jima, moving north-northwestward at 8 kts. The storm's motion gradually shifted more to the west-northwest on 30 August as the TUTT filled and drifted northeastward and the ridge strengthened. JTWC upped the MSW to 55 kts at 30/0000 UTC, and at 1200 UTC the storm was upgraded to a 70-kt typhoon, based on CI estimates of 65 and 77 kts. (JMA and NMCC were estimating the 10-min avg MSW at 55 kts.) At 1800 UTC Typhoon Sinlaku was located approximately 580 nm east of Iwo Jima, tracking west- northwestward at 11 kts. JTWC upped the MSW to 80 kts while NMCC and JMA increased the estimated 10-min avg MSW to 60 kts. Sinlaku's track became increasingly westerly on 31 August as the ridge to the north strengthened. By 1800 UTC the typhoon was approximately 350 nm east of Iwo Jima and moving westward at 8 kts. JMA and NMCC upgraded Sinlaku to typhoon status at 31/0000 UTC, and JTWC upped the MSW to an initial peak of 110 kts at 0600 UTC, based on CI estimates of 90 and 115 kts. The intensity was lowered slightly to 105 kts at 1800 UTC based on a weakening trend in deep convection. Convection had started to make a comeback, however, by 0000 UTC on 1 September, and at 0600 UTC Typhoon Sinlaku reached its peak intensity of 115 kts, based on CI estimates of 102 and 115 kts. JMA's and NMCC's peak 10-min avg MSW estimates were 80 and 100 kts, respectively, and the minimum CP estimated by JMA was 950 mb. At Sinlaku's peak gales extended outward from the center 160 nm in the southern semicircle and from 180 to 200 nm to the north. The radius of 50-kt winds was estimated at 75 nm. A 01/1200 UTC SSM/I pass indicated that the typhoon was undergoing an eyewall replace- ment cycle. By 1800 UTC satellite intensity estimates had come down to 90 and 102 kts and JTWC reduced the MSW to 105 kts. The typhoon was centered at that time about 100 nm east-southeast of Iwo Jima, moving westward at 11 kts along the mid-level subtropical ridge. The center of Typhoon Sinlaku passed about 29 nm south of the southwestern tip of Iwo Jima around 0215 UTC on 2 September. The storm was slowly weakening at this time--possibly due to the eyewall replacement cycle noted above, and also due to its passage over cooler SSTs left in the wake of previous typhoons which had moved through the area. A SSM/I pass at 01/2107 UTC had indicated concentric eyewalls, and the intensity was reduced to 100 kts at 0000 UTC based on CI estimates of 102 kts. The MSW was further lowered to 95 kts at 0600 UTC and to 90 kts at 1200 UTC, based on CI estimates of 77 and 90 kts. Deep convection had weakened in the north- west quadrant, and a 02/1020 UTC SSM/I pass suggested that the eye had reformed with a diameter of 65 nm. Typhoon Sinlaku at 1200 UTC was located approximately 610 nm east of Kadena AB, Okinawa, moving westward at 13 kts. The MSW had fallen steadily to 90 kts (CI 5.0) by 0000 UTC, 3 September, and the CP had leveled out at 955 mb. Typhoon Sinlaku, then located 465 nm east of Kadena, Okinawa, was moving westward at 14 kts along the southern periphery of the mid-level subtropical ridge centered near 35N, 149E. Its passage over warmer SSTs resulted in increased deep convection near the center. However, dry air entrainment from the west counteracted further strengthening and the MSW increased only slightly to 95 kts at 1800 UTC, 4 September. At 1200 UTC the eye (50 nm in diameter) of Sinlaku began to cross Okinawa as observed by radar and satellite imagery. Winds of 63 kts gusting to 99 kts were reported just before eye passage. Kadena AB reported a MSW of 50 kts (1-min avg), gusting to 70 kts, as the eastern edge of the eye passed. A peak gust of 103 kts was recorded at approximately 04/2130 UTC. (More observations follow below.) The overall intensity of Sinlaku remained constant at 90 kts (CI 5.0) through 5 September. A SSM/I pass at 1119 UTC indicated that the deep convection was in the northern quadrants, and that the southern eyewall was weakening. During this time a longwave trough was moving northward of the cyclone. The longwave trough intensified, slowing the forward speed of Sinlaku to 4 kts. High-pressure building from eastern China followed in the wake of the trough, pushing Typhoon Sinlaku on a west- southwestward track. The cyclone was now on a steady weakening trend, and a 05/2153 UTC SSM/I pass indicated that convection in the eyewall had weakened. The storm had turned to a temporary northwestward heading by 07/0000 UTC, likely caused by a weakness in the ridge created by a major shortwave trough over the Sea of Japan. At 0000 UTC, 7 September, Sinlaku was centered 140 nm east of Fujian Province in China. The typhoon continued to track westward once more and moved over the east coast of China near Wenzhou City close to the Zhejiang-Fujian border around 1030 UTC on 7 September with the MSW esti- mated at 70 kts. The tropical cyclone weakened rapidly as it moved farther inland. HKO and CWBT issued their final bulletins at 2100 UTC. JTWC ceased warning on the system at 08/0000 UTC while NMCC issued the final warning at 1200 UTC on 8 September. Despite moving inland over the mountainous terrain of China, the weakening Sinlaku maintained a very well-defined circular cloud pattern on satellite images for the next few days. (Note: At the time of landfall, JMA and JTWC were estimating the intensity at 70 kts, whereas NMCC's reported 10-min avg MSW was 80 kts. HKO's and CWBT's estimates at the time were 80 kts and 75 kts, respectively.) C. Meteorological Observations ------------------------------ (1) Iwo Jima The center of Typhoon Sinlaku passed about 29 nm south of the south- western tip of Iwo Jima around 0215 UTC on 2 September. As early as 01/2100 UTC winds were northerly at 40 kts. By 0102 UTC on 2 September the sustained wind (10-min avg) was northeasterly 60 kts, gusting to 91 kts. The maximum sustained wind was 71 kts at 0238 UTC, while the peak gusts recorded were 99 kts at 0238 and 0320 UTC. As late as 02/0500 UTC the wind was east-southeasterly at 55 kts, gusting to 76 kts. The minimum SLP recorded was 976 mb from 0200 through 0300 UTC. (2) Wind Observations from Okinawa As noted above the large eye of Typhoon Sinlaku passed over the island of Okinawa on 4 September, beginning around 1200 UTC. At Kadena AB winds had increased to gale force by 04/0755 UTC when they were north-northwesterly at 36 kts, gusting to 52 kts. The peak winds before eye passage were 63 kts (1-min avg) at 1122 UTC with a gust of 99 kts. The minimum SLP measured in the eye was 954.8 mb at 04/1555 UTC. As the eastern eyewall passed over the station, the sustained wind reached a peak of 51 kts at 2321 UTC, gusting to 79 kts. However, gusts to 89 kts were recorded at 2144 and 2258 UTC, and the peak gust of 103 kts occurred at approximately 2130 UTC (this from the JTWC 05/0000 UTC warning). Sustained winds had dropped below gale force by around 05/0400 UTC but were still gusting to 35 kts at 0835 UTC when the data record ends. At the Naha Airport the winds were north-northwesterly at 39 kts, gusting to 50 kts, by 04/0600 UTC. The peak sustained wind prior to eye passage was 69 kts (10-min avg) at 04/1200 UTC with a maximum gust of 89 kts. After the eye the 10-min mean wind reached a peak of 67 kts at 04/2137 UTC with the highest gust of 90 kts recorded at 2200 UTC. As late at 05/0800 UTC the wind was southerly 41 kts, gusting to 56 kts. The SLP was 954 mb from 1400 UTC through 1700 UTC. (A special thanks to Roger Edson for sending me the observations from Iwo Jima and Okinawa. The sustained winds from Iwo Jima and Naha Airport are based on a 10-min averaging period while the Kadena AB winds represent a 1-min average.) (3) Rainfall Reports from Okinawa After the report on Typhoon Sinlaku was completed, I received some additional station reports from Okinawa from Huang Chunliang. Since the winds recorded on Okinawa have been covered rather well in the above section, I'm only including rainfall reports here. The strongest winds noted in any of the material from Chunliang were 66 kts sustained (10-min avg) from JMA station 91011. The rainfall amounts (with one exception, which is annotated) represent two-day totals recorded on 4 and 5 September, local time. Station JMA Station WMO Rainfall Name Code Code Coordinates 2-day Total ---------------------------------------------------------------------- Izena 91011 N/A 26.9N, 127.9E 190 mm Oku 91021 N/A 26.8N, 128.3E 452 mm Higashi 91081 N/A 26.6N, 128.2E 288 mm Nago N/A 47940 28.6N, 128.0E 342 mm Goya 91161 N/A 26.3N, 127.8E 348 mm Naha N/A 47936 26.2N, 127.7E 382 mm Yoron Jima 88986 N/A 27.0N, 128.4E 315 mm Miyakojima N/A 47927 24.8N, 125.3E 263 mm ** Kin 91126 N/A 26.5N, 127.9E 234 mm Itokazu 91241 N/A 26.2N, 127.8E 222 mm ** - The amount from Miyakojima was a 24-hour total for 6 September only. (4) Rainfall Reports from China Ten stations in Zhejiang recorded twelve-hour (0000-1200 UTC) rainfall amounts exceeding 100 mm. Reports include: Wenling - 140 mm, Ruian - 139 mm, Dachen Dao - 133 mm, Dongtou - 131 mm, Leqing - 120 mm, Yuhuan - 120 mm, Pingyang - 112 mm, Taishun - 108 mm, Yongjia - 106 mm, and Wenzhou - 104 mm. Over the 24-hour period from 07/0000 to 08/0000 UTC: Wenzhou - 215.4 mm, Pingyang - 193.6 mm, Ruian - 191.1 mm, Wenling - 176.2 mm, and Taishun - 156.4 mm. In Ningde, Fujian Province, Zherong and Fuding stations reported 173 mm and 171 mm, respectively, during the period 07/0400-07/1500 UTC. During the period 04/1600 to 07/1200 UTC rainfall amounts on Taiwan varied from CEIETUAN, Ilan County - 387 mm; FU SHAN, Taipei County - 381 mm; YU-FENG, Hsinchu County - 358 mm; YANMINSHAN - 372 mm; KAO JI, Taoyuan County - 303 mm; KUAN WU, Miaoli County - 213 mm; and TIEN-MU, Taipei City - 199 mm. (5) Wind Observations from China Wind observations from Zhengjiang Province include: During the period from 07/0400-07/0500 UTC, Nanji Dao, Pingyang County, Wenzhou City recorded a peak gust of 110 kts--the highest recorded since weather records began. Two other stations in Zhejiang, Dongtou and Leqing, reported gusts of 83 kts and 74 kts, respectively. Other peak gust reports include: Yuhuan - 89 kts, Kanmen - 87 kts, Dachen Dao - 82 kts, Dongtou - 78 kts, Wenling - 64 kts, and Shipu - 62 kts. Also, Kanmen, a fishing harbor in Yuhuan County, recorded a gust of 90 kts at 07/0502 UTC. Wind observations from Fujian Province include: Fuzhou and Ningde Cities reported gusts exceeded gale force. Shacheng, Fuding City (just south of the easternmost end of the Fujian-Zhejiang boundary), recorded a gust of 64 kts while the peak gust in Fuzhou was 37 kts. According to another report, Fuding recorded a peak gust of 68 kts at 07/1200 UTC. (Note: Fuding is a sub-city of Ningde City.) (A special thanks to Huang Chunliang of Fuzhou City for sending the Chinese observations, as well as most of the following information on damage and casualties.) D. Damage and Casualties ------------------------ Thirty-two people were reported to have died as a result of Typhoon Sinlaku. The storm made landfall on the Fujian-Zhejiang border at 1030 UTC, 7 September. Most of the deaths occurred in Zhejiang Province (there was only one reported dead in Fujian). There were no reports of casualties on Taiwan. Over 8,200,000 residents were affected by the typhoon in Zhejiang. Some 470,000 residents had been evacuated to safer areas in the province before the arrival of the storm. The number of collapsed houses exceeded 23,000. Direct economic losses there were estimated at 3.31896 billion yuan. Approximately 2,210,000 residents were affected by the typhoon in Fujian. Some 170,000 residents had been evacuated to safer areas in the province before the arrival of the storm. In Fujian Province 35,000 houses were destroyed. Direct economic losses there were estimated at 2.559 billion yuan. (In the provincal capital, Fuzhou City, 93,500 residents were affected by the storm with 61 homes collapsed. Direct economic losses to Fuzhou City were estimated at 158.36 million yuan.) Also, at around 07/0500 UTC, the typhoon sank a 6484-ton Korean freighter coded "Pioneer", which was located at 26.20N, 120.62E at the time. Drifting on the sea for a day, seven persons on board were rescued by a fishing boat (numbered 0567) of Lianjiang County, Fuzhou City. The other eight were still missing as of the date of the report (10 September). Sinlaku crossed Okinawa on 4 September, injuring at least 29 people with five reported missing. There were no other reports of casualties. (Report written by Gary Padgett and Kevin Boyle with significant contributions by Huang Chunliang) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for August: No tropical cyclones ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for August: No tropical cyclones ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for August: No tropical cyclones ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for August: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for August: 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 August as an example: aug02.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: aug02.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. 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 (Northeast Pacific, North Indian Ocean, Western Gulf of Mexico) E-mail: dosidicus@aol.com Kevin Boyle (Eastern Atlantic, Western Northwest Pacific) E-mail: newchapelobservatory@btinternet.com ************************************************************************* ************************************************************************* >> Uploaded: 10-29-02 / Typhoon2000.com / Typhoon2000.ph