GARY PADGETT'S MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY NOVEMBER, 2004 (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.) ************************************************************************* NOVEMBER HIGHLIGHTS --> Philippines experience deadly visits from tropical systems --> Surprise Atlantic storm forms on last day of official season --> Two storms--one intense--form in Southwest Indian Ocean --> Arabian Sea cyclone forms almost on equator ************************************************************************* ***** Feature of the Month for November ***** A REVIEW OF THE 2003-2004 TROPICAL CYCLONE SEASON FOR THE SOUTHERN HEMISPHERE Following is a tabular summary of all the tropical depressions and tropical cyclones which occurred in the Southern Hemisphere between 1 July 2003 and 30 June 2004 as reported in the Monthly Global Tropical Cyclone Summaries prepared by the author. (1) Number - this is the sequential cyclone number assigned by JTWC in Hawaii. (2) Name - the name (if any) assigned by the responsible Tropical Cyclone Warning Centre. For systems in the South Indian Ocean west of 90E and in the Southwest Pacific east of 160E which were unnamed, the alphanumeric designator applied by La Reunion or Fiji, respectively, is given in this column. (3) Dates - range of dates for which tracking information for the cyclone is available in the Global Tropical Cyclone Tracks files prepared by the author. The dates given in most cases refer to the time the system was in warning status and generally do not include the pre-depression stages of the disturbance. (4) Pressure - Lowest central pressure (either estimated or recorded) during the lifetime of the cyclone. An asterisk (*) following the pressure indicates the reading was an actual measured pressure. Central pressure is given in millibars, which is numerically equivalent to hectopascals. (5) MSW 1-min avg - maximum 1-minute average sustained windspeed in knots as assigned by JTWC. An asterisk (*) following the MSW indicates that it was an actual measured value. (6) MSW 10-min avg - maximum 10-minute average sustained windspeed in knots as assigned by the responsible Tropical Cyclone Warning Centre. An asterisk (*) following the MSW indicates that it was an actual measured value. (7) Basins - tropical cyclone basins where the cyclone tracked during its life: SWI - Southwest Indian Ocean - West of 90E AUW - Northwest Australia/Southeast Indian Ocean - 90E to 135E AUE - Northeast Australia/Coral Sea - 135E to 160E SPA - South Pacific Ocean - East of 160E SAT - South Atlantic Ocean A number in parentheses (e.g. (1) ) following an entry refers to a note following the entries for the given basin. A separate table is given for each of the four Southern Hemisphere basins. Abbreviations for Tropical Cyclone Warning Centres: JTWC - Joint Typhoon Warning Center, formerly on Guam, now at Pearl Harbor, Hawaii MFR - Meteo France Reunion (RSMC La Reunion) RSMC - Regional Specialised Meteorological Centre ************************************************************************ SOUTH ATLANTIC OCEAN JTWC NAME DATES CENT MSW MSW BASIN NUM PRS 1-MIN 10-MIN (mb) (kts) (kts) ------------------------------------------------------------------------ 01T Catarina 19-28 Mar --- 85 -- SAT (1) NOTES: (1) The number "01T" was unofficially assigned by Julian Heming of the UK Meteorological Office. The name "Catarina" was apparently used by the Brazilian news media. The track included in the March tropical cyclone tracks file was supplied by Roger Edson. Prior to Catarina, back in January, another tropical cyclone of tropical depression or minimal tropical storm intensity occurred just off the tropical Brazilian coastline. No track was available for this system. ************************************************************************ SOUTHWEST INDIAN OCEAN JTWC NAME DATES CENT MSW MSW BASIN NUM PRS 1-MIN 10-MIN (mb) (kts) (kts) ------------------------------------------------------------------------ 01S Abaimba 29 Sep-04 Oct 990 50 45 SWI 02S Beni 09-22 Nov 935 105 100 SWI 03S Cela 05-21 Dec 968 65 65 SWI 06S Darius 29 Dec-04 Jan 976 65 55 SWI 09S Elita 26 Jan-12 Feb 974 65 60 SWI 10S Frank 27 Jan-07 Feb 925 125 105 SWI 16S Gafilo 02-15 Mar 895 140 125 SWI 21S (MFR-11) 13-28 Mar 1002 30 25 AUW/SWI 23S Juba 05-15 May 980 65 55 SWI ************************************************************************ NORTHWEST AUSTRALIA / SOUTHEAST INDIAN OCEAN JTWC NAME DATES CENT MSW MSW BASIN NUM PRS 1-MIN 10-MIN (mb) (kts) (kts) ------------------------------------------------------------------------ 04S Jana 07-12 Dec 960 80 75 AUW 05P Debbie 17-21 Dec 970 65 65 AUE/AUW 08S Ken 01-06 Jan 992 35 40 AUW 11S Linda 28 Jan-01 Feb 978 45 55 SWI/AUW --- ----- 08-12 Feb 994 -- 30 AUW 14S Monty 26 Feb-02 Mar 935 110 95 AUW 17S Nicky-Helma 08-13 Mar 972 70 60 AUW/SWI 18S Fay 14-28 Mar 910 120 115 AUW 20S Oscar-Itseng 20-28 Mar 935 110 95 AUW/SWI ************************************************************************ NORTHEAST AUSTRALIA / CORAL SEA JTWC NAME DATES CENT MSW MSW BASIN NUM PRS 1-MIN 10-MIN (mb) (kts) (kts) ------------------------------------------------------------------------ --- ----- 30 Dec-01 Jan 996 -- 35 AUE (1) 12P Fritz 08-12 Feb 985 35 45 AUE 15P Evan 29 Feb-06 Mar 994 35 40 AUE/AUW --- ----- 02-05 Mar 994 -- 55 AUE (2) 19P Grace 18-24 Mar 985 35 50 AUE/SPA --- (13F) 10-20 Apr 1002 -- 30 AUE/SPA NOTES: (1) System was described in warnings from Brisbane as a monsoon LOW. The center was actually east of 160E during much of its life. (2) System was not a true tropical LOW but more hybrid in nature. ************************************************************************ SOUTH PACIFIC OCEAN JTWC NAME DATES CENT MSW MSW BASIN NUM PRS 1-MIN 10-MIN (mb) (kts) (kts) ------------------------------------------------------------------------ 07P Heta 28 Dec-11 Jan 915 140 115 SPA 13P Ivy 21-29 Feb 935 110 90 SPA --- (06F) 20-22 Mar 994 -- 25 SPA (1) --- (08F) 30 Mar-01 Apr 1002 -- 40 SPA (1) --- (09F) 01-03 Apr 1000 -- 30 SPA (1) 22P (10F) 04-09 Apr 995 35 32 SPA --- (12F) 07-12 Apr 1002 -- 25 SPA --- ----- 02-03 May 998 -- -- SPA (2) NOTES: (1) Gales were associated with these systems but were well-removed from the center. (2) No maximum wind estimates were given in the Fiji summaries for this system, and it likely was not purely tropical but rather hybrid in nature. Peripheral gales of up to 40 kts were forecast for this system. ************************************************************************ ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for November: 1 tropical storm 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. Atlantic Tropical Activity for November --------------------------------------- A non-tropical LOW in the central Atlantic in late November began to acquire subtropical characteristics as the end of the month drew nigh. By midday on 30 November--the last day of the official 2004 Atlantic hurricane season--Tropical Storm Otto was christened after the system had developed tropical characteristics. The last time that a tropical storm was named on 30 November was in 1989 when Tropical Storm Karen formed in the northwestern Caribbean Sea. Hurricanes Nicole and Olga of 1998 and 2001, respectively, were still operating at the end of the June to November season and continued into the month of December. And in 2003 Tropical Storms Odette and Peter both formed during the first week of December. A couple of other systems which occurred during November deserve some mention. During the second week of the month an area of disturbed weather formed just north of Panama and extended northeastward across the central Caribbean to Hispaniola and Puerto Rico. The convective activity was triggered by the interaction of an elongated area of low pressure and an upper-level trough. The system's organization improved during the afternoon of 9 November and the STWOs issued by TPC/NHC mentioned the possibility that a tropical or subtropical cyclone could form in the area. Upper-level winds remained only marginally favorable for strengthening and the system was never able to develop well-enough to be classified as a depression. The primary threat presented by the LOW was the potential for very heavy rainfall with attendant flooding and mudslides in the Antilles. A large non-tropical low-pressure system formed on 11 November and was located about 600 nm southwest of the southernmost Azores Islands. Gales had developed and some convection was beginning to form near the LLCC. The potential for subtropical storm development was mentioned in the STWOs issued by TPC/NHC, but upper-level winds remained unfavorable for further subtropical or tropical development of this system. A short report on Tropical Storm Otto, based on the official TPC/NHC storm report, follows. TROPICAL STORM OTTO (TC-16) 27 November - 5 December -------------------------------------------- Tropical Storm Otto's origins lay with a cold front which emerged off the East Coast of the United States on 21 November. This front moved slowly eastward and eventually stalled about midway between Bermuda and the Azores Islands on the 25th. An extratropical LOW had formed along the front about 1000 nm southwest of the Azores by 0000 UTC on 26 November. Later on the same day the occluded surface low- pressure system deepened and gales began to affect a large area. The upper-level trough which had initiated the LOW's development continued to dig southward and formed a cut-off LOW to the south of the surface LOW late on the 26th. The surface and upper-level LOWs moved southwestward slowly in tandem for a couple of days. Late on the 28th weak ridging to the north of the upper-level LOW formed over the surface LOW and convective banding features began to develop near the LLCC. Also, surface data and analyses indicated that the cyclone's frontal structure had dissipated. In post- analysis it was determined that the system had acquired subtropical storm characteristics by around 1200 UTC on 29 November while centered about 1000 nm east-southeast of Bermuda. The subtropical LOW then began moving northwestward through a weakness in the mid-level subtropical ridge located to the north. Convection continued to increase over the LLCC and AMSU satellite-derived temperature data indicated that the system had transformed into a warm-core tropical cyclone by the 30th. The first advisory on Tropical Storm Otto was issued at 2100 UTC, locating the center approximately 700 nm east of Bermuda. During its life as a tropical storm Otto meandered over relatively cool SSTs of around 21-23 C in a region of relatively weak vertical shear, but a marginally favorable upper-level flow pattern allowed the cyclone to maintain some central deep convection. Otto turned slowly southeastward on 1 December as vertical shear increased, causing the system to begin slowly weakening. Mid-level dry air entrainment also contributed to Otto's demise. The storm was downgraded to a tropical depression at 1200 UTC on 2 December, and Otto became a non-convective remnant LOW on 3 December about 800 nm southeast of Bermuda. Operationally, Otto's peak MSW was estimated at 45 kts at 0600 UTC on 1 December. However, the "best track" indicates that the peak intensity of 45 kts occurred during the subtropical storm stage and that during the tropical storm portion of Otto's life the MSW never exceeded 40 kts. This report was condensed from the official TPC/NHC storm report on Tropical Storm Otto, authored by Stacy Stewart. The report may be accessed at the following URL: The report seems to indicate that Otto was named as a subtropical storm on 29 November. However, the name was not assigned until the first advisory as a tropical storm was issued at 30/2100 UTC. NHC employs a fairly restrictive definition of a subtropical storm, i.e., not all "hybrid" storm systems--not even all non-frontal systems--are considered subtropical storms. There is a broad spectrum of cyclone types based on their energetics and thermal characteristics, and the boundaries between the three primary categories of tropical, subtropical and extratropical are somewhat fuzzy. Hence, it is not always possible to make the best determination as to how to classify a cyclone in real time, and very often it is during the post-storm analysis process that it is decided to reclassify a non-tropical LOW as a subtropical cyclone. Such was the case with the early stages of Tropical Storm Peter in December of 2003, and with the June, 1997, and October, 2000, subtropical storms. (Brief report written by Gary Padgett, based upon TPC/NHC storm report written by Stacy Stewart) ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for November: No tropical cyclones ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for November: 3 tropical depressions ** 1 tropical storm ++ 1 typhoon 1 super typhoon ** - two of these were classified as tropical depressions by JMA only; another by JMA and PAGASA ++ - classified as a tropical storm by several Asian TCWCs but not by JTWC Sources of Information ---------------------- Most of the information presented below is based upon tropical cyclone warnings and significant tropical weather outlooks issued by the Joint Typhoon Warning Center of the U. S. Air Force and Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion tropical cyclone tracks file, I normally annotate track coordinates from some of the various Asian warning centers when their center positions differ from JTWC's by usually 40-50 nm or more. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. Michael V. Padua of Naga City in the Philippines, owner of the Typhoon 2000 website, normally sends me cyclone tracks based upon warnings issued by the Japanese Meteorological Agency (JMA) and the Philippine Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). Also, Huang Chunliang of Fuzhou City, China, sends data taken from synoptic observations around the Northwest Pacific basin. 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. Northwest Pacific Tropical Activity for November ------------------------------------------------ Tropical cyclone activity in November was somewhat above the average, and the Philippines--the island of Luzon in particular--was the target of all the named tropical systems forming during the month. After following an erratic course and executing a loop just east of central Luzon, Typhoon Muifa/Unding dropped southwestward and struck the south- eastern portion of the island on the 19th. Only four days later, minor Tropical Storm Merbok/Violeta struck eastern Luzon. During the closing days of November, the weak but quite wet Tropical Depression Winnie brought more misery to the island in the form of torrential rainfall which led to flash flooding and landslides. Finally, as the month ended Super Typhoon Nanmadol/Yoyong developed south of Guam and raced at a very fast clip toward the Philippines, crossing central Luzon on the 2nd of December. Reports on all these tropical cyclones follow, three being written by Kevin Boyle with significant contributions by Huang Chunliang and Michael V. Padua. Because Unding, Violeta, Winnie and Yoyong (their PAGASA names) all affected the Philippines within a space of two weeks, it is all but impossible to determine the exact number of casualties caused by each one. Information contained in Kevin Boyle's report on Typhoon Nanmadol (the last one) indicates that over 1000 deaths were related to the parade of tropical cyclones. More information on the effects of these storms in the Philippines may be found at the following URL: Additionally there were two weak systems which were classified as tropical depressions by JMA only. The first of these formed on the 16th west-southwest of Guam and remained essentially stationary through the 18th. This disturbance was given a fair potential for development at one point by JTWC, but no TCFA was issued. The second weak system formed a few hundred miles east of central Luzon on 21 November and was classed as a tropical depression by JMA for only 12 hours. This weak disturbance was not mentioned by JTWC in their STWOs. No tracks were included for these weak systems in the companion tropical cyclone tracks file. TYPHOON MUIFA (TC-29W / TY 0425 / UNDING) 14 - 26 November ----------------------------------------------- Muifa: contributed by Macau, is a type of plum blossom which can withstand very cold weather--also represents a strong-minded Chinese A. Storm Origins ---------------- The disturbance that was to become Typhoon Muifa was first mentioned in JTWC's STWO at 1600 UTC 13 November when it was located approximately 215 nm north of Palau. At this time, development of a significant tropical cyclone was assessed as 'poor'. A TCFA was issued at 13/2000 UTC after the system showed a rapid spurt in development, and the first warning followed at 14/0000 UTC. At this time Tropical Depression 29W exhibited a partially-exposed LLCC with the strongest convection in the western semicircle. The disorganized-looking cyclone tracked westward, accelerating to around 14 kts along the southern boundary of the sub- ridge situated to the north, and became a 35-kt tropical storm at 14/1200 UTC when it was centred 550 nm east-southeast of Manila, Philippines. It was named Muifa at 14/1800 UTC after JMA upped their 10-min avg MSW to 35 kts. PAGASA had assigned the name Unding at 14/0000 UTC after the tropical cyclone had invaded their area of responsibility. B. Synoptic History ------------------- At 0000 UTC 15 November Tropical Storm Muifa/Unding was moving west- northwest at 9 kts approximately 430 nm east-southeast of Manila, Philippines. The system didn't look that much more impressive with most of the deep convection separated from the LLCC. Also, it was discovered that the centre was positioned further east than previously analysed. The MSW remained at the 35-kt threshold for the rest of the day, although Muifa gradually became more organized. At 16/0000 UTC the tropical cyclone turned abruptly towards the north-northeast and decelerated to 4 kts. At this time it was relocated to a position 300 nm east of Manila, based on multi-spectral and microwave fixes which clearly showed the LLCC east-southeast of the deep convection. Muifa turned back onto a west-northwesterly heading and began to intensify. At the time of the next relocation at 16/0600 UTC, the MSW had climbed to 45 kts and this repositioning placed the centre closer to Manila, approximately 215 nm to the east, and under the deep convection. Muifa continued to strengthen and reached an intensity of 55 kts by 16/1800 UTC. At this time it appeared much better organised in satellite imagery. At 0000 UTC 17 November Tropical Storm Muifa/Unding was creeping slowly westwards approximately 140 nm east of Manila, Philippines. It was upgraded to a 65-kt typhoon at 17/0600 UTC, but convection had waned somewhat despite the fact that microwave imagery revealed the early development of an eye. Erratic movement commenced at 17/1200 UTC and Muifa began the first leg of its clockwise loop which took a couple of days to complete. Strengthening had continued and by 17/1800 UTC the intensity had reached 90 kts. The centre of the typhoon was located 170 nm east-northeast of Manila at this time. Muifa's MSW reached 100 kts at 18/0000 UTC as it moved northwards at around 2 kts. The eye became better defined in multi-spectral imagery at 18/0600 UTC when the storm came to a virtual standstill. At 18/1200 UTC Muifa peaked at 115 kts before beginning a marked weakening phase at 18/1800 UTC. The MSW at this time had decreased to 105 kts. At this time, the northern eyewall had eroded with the strongest convection located in the southern portion. The tropical cyclone had veered to a slow southeasterly heading, seemingly moving away from the Philippines. Typhoon Muifa/Unding weakened further to 95 kts at 0000 UTC 19 November as its heading slowly pivoted towards the southwest approximately 200 nm east-northeast of Manila, Philippines. The storm's forward motion began to increase at 19/0600 UTC as it sank south- southwestward towards southern Luzon. Muifa/Unding made landfall at 19/1300 UTC in the vicinity of Naga City with a MSW of 70 kts. The system staggered its way across the Philippine Archipelago, weakening as it went, and was downgraded to a 60-kt tropical storm at 20/0600 UTC. This intensity was maintained for the rest of the day. By this time, Muifa/Unding was centred 135 nm south-southwest of Manila, having emerged into the South China Sea. At 21/0000 UTC a small increase in the MSW to 65 kts meant that Muifa was upgraded back to typhoon intensity. Further strengthening occurred as the tropical cyclone made its way west to west- southwestwards across the warm waters of the South China Sea, and by 21/1800 UTC Muifa had re-strengthened into a 90-kt typhoon approximately 440 nm east of Ho Chi Minh City, Vietnam. A slight weakening occurred at 0000 UTC 22 November as Muifa continued its way westward towards Vietnam. This heading was taking the storm into an environment of drier air and increasing vertical shear. At 22/0600 UTC the intensity was down to 75 kts, and by 22/1800 UTC Muifa was a minimal typhoon located approximately 320 nm east of Ho Chi Minh City, Vietnam. At this time, the cyclone's motion was still a rather wobbly west-southwest to southwest movement, and the forward speed had slowed to around 4 kts. Muifa held onto typhoon status until 23/1200 UTC when the MSW fell below 65 kts. The system continued to slowly sink generally towards the southwest, maintaining 55-kt winds for awhile during the 24th, but the intensity further dropped to 45 kts at 24/1200 UTC when it was centred 215 nm southeast of Ho Chi Minh City, Vietnam. The LLCC had, by this time, become partially-exposed and was moving in a different direction to that of the deep convection. At 24/1800 UTC microwave imagery indicated the LLCC was further west than previously analyzed, supporting a relocation to a position 160 nm south-southwest of Ho Chi Minh City. At 0000 UTC 25 November Tropical Storm Muifa was picking up steam and had veered onto a westerly course at a forward speed of 21 kts. The system continued to weaken and was downgraded to tropical depression status at 25/1200 UTC after the MSW had fallen to 30 kts. Six hours later, Muifa was located off southern Thailand and passing approximately 250 nm south of Bangkok. Interaction with the terrain of Thailand finished the storm off and the best way to describe the LLCC was as a disorganized mess. At 26/0000 UTC Muifa turned northward into an environment of increased wind shear and as the intensity had fallen to 25 kts, JTWC issued the final warning on Typhoon Muifa. The final position was 120 nm south-southwest of Bangkok. JMA had ceased issuing bulletins at 25/1200 UTC. At its peak intensity, Typhoon Muifa was representative of an average- sized storm with the radius of 64-kt winds extending up to 25 nm from the centre while gales lay up to 90 nm in the northern semicircle. The 34-kt wind radii in the southwestern and southeastern quadrants were 110 nm and 80 nm, respectively. JMA's estimated peak intensity was 80 kts (10-min avg) with the lowest CP at 955 mb. This strength meant that JMA classified Muifa as a Severe Typhoon. Also, HKO, CWB and TMD estimated Muifa as an 80-kt typhoon. NMCC considered Muifa as a stronger 90-kt storm while PAGASA's maximum intensity during the period it was within their area of responsibility was 65 kts. C. Damage and Casualties ------------------------ The death toll reported from the Philippines, based on data released by the Philippines' National Disaster Coordinating Council (NDCC), stands at 68 dead, 160 injured, and 69 unaccounted for. A total of 26,238 houses were destroyed and 76,062 damaged. Cost estimates include (in pesos): Agriculture: 405.3 million Fisheries: 76.1 million Infrastructure: 371.0 million Transmission Facilities: 26.6 million School Facilities: 130.0 million Total: 1,008.9 million Typhoon Muifa also had a destructive impact on Vietnam. Floods and landslides triggered by the typhoon killed about 40 people, and 40 more people were reported missing. There were also many villages in the mountains which needed urgent relief but which could not be quickly reached. Hoi An, which is the town of world heritage, was hit by the flood, and more than 80 old houses were in danger of collapse. D. Huang Chunliang Report from the Philippines ---------------------------------------------- === Brief Report on Typhoon UNDING {MUIFA} === (Rainfall Obs from Philippines) Only daily amounts >= 100 mm listed: BORONGAN (WMO98553 11.65N 125.43E) 103.6 mm [14/00-15/00Z] CATANDUANES RADAR (WMO98447 13.98N 124.32E) 246.4 mm [15/00-16/00Z] VIRAC (WMO98446 13.58N 124.23E) 207.3 mm [15/00-16/00Z] CATARMAN (WMO98546 12.50N 124.63E) 122.0 mm [15/00-16/00Z] CATANDUANES RADAR (WMO98447 13.98N 124.32E) 182.4 mm [16/00-17/00Z] PILI (WMO98442 13.57N 123.27E) 151.2 mm [16/00-17/00Z] DAET (WMO98440 14.13N 122.98E) 127.6 mm [16/00-17/00Z] VIRAC (WMO98446 13.58N 124.23E) 123.0 mm [16/00-17/00Z] SAN JOSE (WMO98531 12.35N 121.03E) 171.4 mm [20/00-21/00Z] TAYABAS (WMO98427 14.03N 121.58E) 103.1 mm [20/00-21/00Z] E. Huang Chunliang Report from Thailand --------------------------------------- === Brief Report on Typhoon MUIFA from Thailand === 1. Landfall ----------- According to the TMD warnings, Tropical Depression MUIFA made landfall near Amphoe Tha Chana, Surat Thani Province around 25/1500 UTC with a MSW of 30 knots. 2. Rainfall (Only 24-hr amounts >= 100 mm listed) ------------------------------------------------- PRACHUAP KHIRIKHAN (WMO48500 11.83N 99.83E) 173.4 mm [25/00-26/00Z] PRACHUAP KHIRIKHAN (WMO48500 11.83N 99.83E) 251.5 mm [25/06-26/06Z] PRACHUAP KHIRIKHAN (WMO48500 11.83N 99.83E) 235.8 mm [25/18-26/18Z] F. Michael Padua Report from Naga City, Philippines --------------------------------------------------- Michael V. Padua, an amateur meteorologist in Naga City and owner of the Typhoon 2000 website, had a Close Encounter of the Third Kind with Typhoon Muifa when the cyclone made landfall near his home. Michael gained a considerable amount of publicity when, convinced that the typhoon was headed for the Naga City area but with the official PAGASA warnings continuing to forecast the storm to head northwestward away from the region, called the mayor of Naga City and advised him to make emergency preparations for Typhoon Muifa. Because of Michael's action, residents of Naga City were somewhat better prepared for the arrival of the typhoon than they would have been otherwise. Following is a portion of Michael's write-up about his experiences (slightly edited): "As I woke up around 6:30 in the morning (2230 UTC) of 19 November, I quickly opened the monitor and refreshed the browser to get the latest satellite image and GOES animation that showed that the system was starting to track more southerly. This prompted me to call our local PAGASA (office) to advise them about the imminent danger. They told me that their main office in Manila still believed that the storm would move west-northwest. At around 10:00 AM (0200 UTC), I drove to our school (Naga College Foundation) and stepped into my office where I got the latest satellite image which continued to show the southward drift of Muifa accelerating a bit--that was barely 12 hours before the eyewall passage over Naga. I had already taken some video of the approach of the outer bands. The pressure reading at the time was still high (1008.7 hPa) with winds gusting up to 14 kts, blowing from the northwest. "As of 11:00 AM (0300 UTC), I received the latest PAGASA bulletin that still showed no Philippine Storm Warning Signals raised over our area. This prompted me again to call up our local PAGASA (office) for the second time around. Then at around 3:00 PM (0700 UTC), I went home to have a late lunch and created a last-minute animation of Muifa. After finishing the animation it was already 4:00 in the afternoon! That was barely six hours before Muifa's destructive approach. By that time the pressure had already dropped to 1004.7 hPa with northwesterly winds reaching 22 kts. I checked the 3:30 PM (0730 UTC) satellite image which showed that Muifa had accelerated further towards the south to south-southwest. I decided to call our city mayor to advise him that we must prepare for the possible nighttime approach of Muifa. I also told him that PAGASA had not yet raised any storm signals over our area. I explained to him that our city should be under Storm Signal Number 3, which means that winds of more than 54 kts could be expected in at least 18 hours, and we were only six hours away from the destructive winds! "The mayor thanked me right away and called an emergency meeting, also notifying the radio stations regarding the danger Naga had to face. Around 4:30 in the afternoon, I quickly drove back to my office, where many students of our college were waiting for me to post what signal we were in. As I plotted the latest position of Muifa (based on the most recent satellite image), I posted the Signal Number 3 an hour before the official PAGASA bulletin went out! At that time all classes and offices were suspended. Then as the PAGASA bulletin went out around 5:30 PM--the signal was still Number 2! "At around 10:00 in the evening, the worst of the typhoon arrived! My Davis Vantage Pro weather station recorded 10-min avg winds of up to 43 kts (NW to N) with gusts reaching 71 kts (north). The highest rain rate was 18 inches (457 mm) per hour, and the lowest pressure recorded was 986.1 hPa at 10:14 PM (1414 UTC). I heard the sound of flying debris and falling trees outside the house as the winds continued to scream. I was then waiting for the sudden lull, but there was no calm. Then, at 11:00 PM the storm's eyewall began to move farther away from Naga, as confirmed by the rapidly increasing pressure which was already up to 992.7 hPa. The 10-min avg winds had diminished to only 27 kts, blowing from the north to northeast (gusting to only 38 kts). By midnight on 20 November the winds had dramatically died down to an average of only 16 kts coming from the east. At around 02:00 AM it was eerily calm as if nothing had happened! I took a 4-hour sleep afterwards." To recap, following are the particulars of Michael's location and his observations: Date: 19-20 November 2004 Location: Naga City, Philippines Lat/Lon: 13.6N/123.2E Instrument: Davis Vantage Pro Weather Station (March 2004 Model) Highest Wind Speed (gust): North 71 kts at 1400 UTC 19 November Lowest Barometric Pressure: 986.1 hPa at 1414 UTC 10 November Highest Rainfall Rate: 457 mm/hour at 1343 UTC 19 November Storm Total Rainfall: 306.5 mm (14-20 November) Michael's excellent full report (with graphcs) on Typhoon Muifa/ Unding can be found at the following link: (Report written by Kevin Boyle with significant contributions by Huang Chunliang and Michael V. Padua) TROPICAL STORM MERBOK (TS 0426 / VIOLETA) 22 - 23 November ----------------------------------------- Merbok: contributed by Malaysia, is the spotted-necked dove, most commonly found in rural areas and in wastelands, and is popular as a caged bird by Malaysians A. Storm History ---------------- Tropical Storm Merbok emanated from a disturbance located in the Philippine Sea and was first recognized as Tropical Depression Violeta by PAGASA at 0000 UTC 22 November when that agency began issuing warnings. Six hours later, JMA began writing bulletins and upgraded the system to a 35-kt tropical storm at 22/1200 UTC, naming the tropical cyclone Merbok. Tropical Storm Merbok tracked slowly towards the northwest and made landfall south of Baer on the east coast of Luzon. The storm's intensity held steady at 35 kts (its peak strength) as it ambled its way across the mountains of Luzon, finally emerging off the northwest coast at 0600 UTC 23 November. By this time, Merbok had lost most or all of its deep convection, the remnants continuing slowly north- westwards before dissipating southwest of Taiwan. Both JMA and PAGASA ceased warning coverage at 23/0600 UTC. PAGASA kept Merbok/Violeta below tropical storm intensity and estimated a peak intensity of 30 kts for this system. JMA estimated a peak intensity of 35 kts with a minimum CP of 998 mb. Other agencies to regard Merbok as a 35-kt tropical storm were NMCC, CWB and TMD while the maximum intensity of Merbok per HKO advisories was 30 kts. JTWC issued no warnings and failed to acknowledge the existence of the disturbance in their STWOs. Tropical Storm Merbok added to the misery caused by Typhoon Muifa/ Unding in the Philippines, killing 31 people and injuring 187 others. In addition, 17 persons were reported missing. A total of 337 houses were destroyed and 1,286 damaged. Total estimated damage reached 253 million pesos with agriculture especially hard hit (210 million pesos.) B. Huang Chunliang Report ------------------------- === Brief Report on Tropical Storm VIOLETA {MERBOK} === (Rainfall Obs from Philippines) Only daily amounts >= 100 mm listed: CASIGURAN (WMO98336 16.28N 122.12E) 185.2 mm [22/00-23/00Z] TUGUEGARAO (WMO98233 17.62N 121.73E) 129.3 mm [22/00-23/00Z] C. Additional Discussion ------------------------ This system was classified as only a tropical depression by PAGASA and HKO. Agencies classifying Merbok as a tropical storm included JMA, NMCC, CWB of Taiwan, and the Meteorological Department of Thailand. I asked Dr. Karl Hoarau to perform an analysis of this tropical cyclone and his conclusion was that Merbok was a tropical storm from around 0000 UTC on 22 November through landfall on Luzon at 1500 UTC that same day, peaking at 40 kts (1-min avg) at 0600 UTC. The Merbok system was never mentioned in the STWOs issued by JTWC. (This paragraph added by Gary Padgett.) (Report written by Kevin Boyle with contributions by Huang Chunliang) TROPICAL DEPRESSION WINNIE 27 - 30 November ---------------------------------------------- Tropical Depression Winnie was a large, sloppily-organized system which brought torrential rains to Luzon, resulting in deadly flashfloods and landslides. Winnie was named by PAGASA when it formed east of the central Philippines on 27 November. JMA and the Central Weather Bureau of Taiwan were the only other agencies classifying Winnie as a tropical depression. A TCFA was issued by JTWC on the 29th but was cancelled the next day. The system formed east of the central Philippines on 27 November and moved west-northwestward over southeastern Luzon on the 29th. After moving well-inland over Luzon, Winnie turned to a more north-northwesterly track up the west side of the island and was last mentioned at 0000 UTC on the 30th when it was located along the northwestern Luzon coast. According to information received from Michael Padua of Naga City, news media reports in the Philippines indicated that more than 300 persons lost their lives during the passage of Tropical Depression Winnie, primarily due to massive flashfloods and landslides in Quezon and Aurora Provinces triggered by the attendant heavy rains. Following are some rainfall observations compiled and sent by Huang Chunliang (thanks to Chunliang for these): Only daily amounts >= 100 mm listed: DAET (WMO98440 14.13N 122.98E) 156.4 mm [28/00-29/00Z] CABANATUAN (WMO98330 15.48N 120.97E) 157.8 mm [29/00-30/00Z] ALABAT (WMO98435 14.08N 122.02E) 144.2 mm [29/00-30/00Z] CASIGURAN (WMO98336 16.28N 122.12E) 117.6 mm [29/00-30/00Z] SANGLEY POINT (WMO98428 14.50N 120.92E) 116.4 mm [29/00-30/00Z] (Brief report written by Gary Padgett with contributions by Huang Chunliang) SUPER TYPHOON NANMADOL (TC-30W / TY 0427 / YOYONG) 28 November - 4 December ----------------------------------------------- Nanmadol: contributed by Micronesia, is a famous Pohnpei ruin, sometimes known as the "Venice of the Pacific" A. Storm Origins ---------------- Super Typhoon Nanmadol developed from a cluster of thunderstorms that was first mentioned in JTWC's STWO at 2200 UTC 27 November when it was located approximately 155 nm south-southwest of Pohnpei. Development potential was assessed as 'fair' and animated enhanced infrared satellite imagery revealed disorganized deep convection consolidating over a possible LLCC. An upper-level analysis revealed good poleward and equatorward diffluence and wind shear in the area was light. A TCFA was issued at 28/0300 UTC after a rapid increase in deep convection was noted over the LLCC and water vapor imagery showed an increasing radial outflow. This statement was followed by the first warning at 28/1800 UTC which centred the newly-formed Tropical Depression 30W some 690 nm east- southeast of Yap. The system was headed in a westerly direction through a low to moderate wind shear environment south of the subtropical ridge. Tropical Depression 31W quickly developed into Tropical Storm Nanmadol when both JTWC and JMA upgraded their respective MSW estimates to 35 kts at 29/0000 UTC. B. Synoptic History ------------------- The Prognostic Reasoning Message issued at 0000 UTC 29 November was not encouraging to say the least. There was high confidence in the long- term forecasts that Nanmadol would make landfall over Luzon, Philippines, an area that had suffered disastrously from heavy rains and flooding from the recent spate of tropical cyclone activity. Nanmadol continued to strengthen and reached typhoon intensity at 29/1200 UTC after passing south of Satawal earlier in the day. At this time infrared and water vapor imagery indicated a very large and symmetric central dense overcast and strong radial outflow in all directions. Also, there were signs of a warm spot, a sign of eye formation. After its upgrade, the storm's track curved onto a west-northwesterly track which would be maintained for several more days to come. At 29/1500 UTC Typhoon Nanmadol was passing the island of Woleai and the intensity had climbed to 75 kts by 29/1800 UTC. Intensification eased for awhile as Typhoon Nanmadol continued its brisk west-northwestward heading towards Yap en route to the Philippines. At 0000 UTC 30 November the storm was located approximately 180 nm east- southeast of Yap. Nanmadol passed just north of the island at 30/0800 UTC, bringing typhoon-force gusts and sustained tropical storm strength winds. Strengthening resumed and the MSW reached 105 kts at 01/0000 UTC. Nanmadol stuttered a bit after the intensity had risen to 125 kts at 01/1200 UTC, and even fell back a bit six hours later. However, the tropical cyclone reached its peak intensity of 130 kts at 02/0000 UTC, a super typhoon, centred 220 nm east of Manila, Philippines. Because of its rapid translational speed Super Typhoon Nanmadol soon arrived at the Luzon coastline and at 02/1200 UTC was poised to make landfall south of the city of Casiguran. At this time, the system began to lose strength and was downgraded from super typhoon status. Turning northwestward Typhoon Nanmadol took roughly six hours to cross the island of Luzon, and by 1800 UTC 2 December had reemerged back over water. It had weakened slightly to 110 kts at this time, and likely its rapid passage across the northern Philippines didn't allow time for the system to weaken significantly. However, this period marked the beginning of the end for the tropical cyclone. The northwesterly turn was to take Nanmadol into a weakness in the subtropical ridge before being dragged off by a major shortwave trough. In addition, upper-level conditions in the vicinity of Taiwan were becoming increasingly unfavourable. In response to this, Nanmadol weakened markedly during the 3rd as it gradually veered more towards the north. Cloud top temperatures rapidly warmed and cold dry air was being sucked into the storm's southwestern quadrant. In addition, the cloud pattern became increasingly asymmetrical, a sign that extratropical transition was beginning. At 03/1200 UTC the LLCC was exposed 130 nm to the south of the deep convection--the centre was then located approximately 210 nm southwest of Kaoshiung, Taiwan. The MSW had dropped to 65 kts by 03/1200 UTC, and six hours later, JTWC issued the final warning, lowering the intensity down to a 55-kt extratropical storm. JMA continued issuing bulletins, tracking Nanmadol east-northeastward across southern Taiwan before ceasing to write bulletins at 04/0600 UTC. (See Huang Chunliang's Report from China--Section E.) The remnants of Super Typhoon Nanmadol continued to rapidly move to the east-northeast and northeast and ultimately merged with another LOW, forming a powerful extratropical cyclone which brought strong winds and advected unseasonably warm temperatures to Japan. At its peak intensity Super Typhoon Nanmadol was a large-sized typhoon. Typhoon-force winds extended as far as 65 nm in the southwest quadrant while gales lay up to 320 nm in the same quadrant. Strong winds extended outward a shorter distance in the northeastern quadrant with 64-kt winds up to 35 nm and gales as far as 190 nm. All Asian agencies, except PAGASA, estimated peak intensities of 90 kts with JMA estimating a minimum CP of 935 mb. PAGASA estimated a peak MSW of 100 kts during the period Super Typhoon Nanmadol/Yoyong was tracking through their AOR. C. Damage and Casualties ------------------------ Because Typhoon Muifa, Tropical Depressions Merbok and Winnie, and Super Typhoon Nanmadol all occurred within a space of two weeks, the exact number of casualties and total cost of damages of each may be difficult to determine. However, the NDCC report indicated that Nanmadol caused 70 fatalities, and 157 injuries with 37 persons unaccounted for. This brings the total of tropical-system related deaths in the Philippines to 1,060. The report also indicated that Nanmadol destroyed 10,457 houses and damaged 57,435. Agriculture also suffered badly as a result of this typhoon with losses amounting to 2,036 million pesos. D. Huang Chunliang Report from the Philippines ---------------------------------------------- === Rainfall Obs from Philippines === (All dates in December) Only daily amounts >= 100 mm listed: CATANDUANES RADAR (WMO98447 13.98N 124.32E) 127.2 mm [01/00-02/00Z] CATARMAN (WMO98546 12.50N 124.63E) 122.0 mm [01/00-02/00Z] DAET (WMO98440 14.13N 122.98E) 228.1 mm [02/00-03/00Z] TANAY (-------- 14.57N 121.37E) 145.6 mm [02/00-03/00Z] VIRAC (WMO98446 13.58N 124.23E) 115.2 mm [02/00-03/00Z] BAGUIO (WMO98328 16.42N 120.60E) 104.9 mm [02/00-03/00Z] E. Huang Chunliang Report from China ------------------------------------ === Report on Typhoon 0428 (NANMADOL)/Moderate === === Typhoon 0427 (NANMADOL) from China === (All dates in December) {Part I}. Landfall ================== According to the CWB warnings, Weak Typhoon 0427 (Nanmadol) made land- fall in southeastern Taiwan near Fangliao, Pingtung County, around 03/2340 UTC with a MSW of 28 m/s and a CP of 980 hPa. The storm then entered the waters east of southern Taiwan from near Taimali, Taitung County, around 04/0130 UTC before transforming into an extratropical cyclone. As a result, Nanmadol made a name for itself as the first December tropical cyclone in the past 108 years to make landfall on the island (typhoon records began in the year 1897). {Part II}. Rainfall Obs from Taiwan =================================== Daily Rainfall [02/16-03/16Z] (only Top 5 listed): Ranking Station ID City/County Rainfall (mm) --------------------------------------------------------------------- 01 CWB C1T83 Hualien County 907.0 02 CWB C0T82 Hualien County 728.0 03 CWB C1T94 Hualien County 632.0 04 CWB C1T95 Hualien County 628.0 05 CWB C1T98 Hualien County 494.5 Note: Puluowan (CWB C1T83) reported the highest storm total accumulation of 1090 mm during the 35-hr period ending at 04/0300 UTC. {Part III}. Rainfall Obs from Fujian ==================================== Nanmadol turned out to be an extremely rare winter tropical cyclone that affected my city. In fact, before Nanmadol, there has never been any tropical cyclone to affect Fujian in the month of December, according to the meteorological records of the province. Fuzhou's coastal county of Lianjiang recorded a 24-hr rainfall amount of 52.3 mm [03/00-04/00Z] (Top 1 in Fujian Province that day), while the urban area (WMO58847), where I live, reported an uninterrupted daily accumulation of 29.7 mm during the same span, the climatic average for the whole month of December being 28.8 mm. Both values were rare for the city at this time of year. {Part IV}. Rainfall Obs from Zhejiang ===================================== Only daily amount >= 100 mm listed: DACHEN DAO (WMO58666 28.45N 121.88E) 106.3 mm [03/00-04/00Z] SHIPU (WMO58569 29.20N 121.95E) 101.9 mm [03/00-04/00Z] YU-HUAN (WMO58667 28.13N 121.22E) 101.8 mm [03/00-04/00Z] {Part V}. Damage and Casualties in Taiwan ========================================= Nanmadol caused 2 deaths with another 2 persons missing in Taiwan. Power supply to 26,588 households was disrupted during the storm. The agricultural losses there were estimated to have been NT$ 670 million. F. Huang Chunliang Report from Japan ------------------------------------ === Report on Extratropical Cyclone === === (December 4-5, 2004) === {Part I}. Introduction ====================== JMA regarded the cyclone as another extratropical system (rather than "ex-Nanmadol") which formed north-northeast of Nanmadol around 04/0000 UTC, then absorbing the latter by 04/1200 UTC. I believe, however, that it's acceptable to label the storm directly as "ex-Nanmadol", though I didn't remember if any of the other agencies had done so. {Part II}. Meteorological Obs from Tokyo District Meteorological Observatory ================================================= Note 1: All the obs in this part were reported within the precinct of Tokyo District Meteorological Observatory, including the prefectures of Niigata, Toyama, Ishikawa, Fukui, Ibaraki, Gumma, Tochigi, Saitama, Tokyo, Chiba, Kanagawa, Yamanashi, Nagano, Shizuoka, Gifu, Aichi and Mie. Note 2: "*" = record-breaking values for relevant stations. Note 3: "#" = record-breaking values of December for relevant stations. 1. Top-5 Storm Total [03/1500-05/1500Z] Obs ------------------------------------------- Ranking Prefecture Station Rainfall (mm) ------------------------------------------------------------- 01 Mie Owase 230 02 Mie Mihama 222 03 Shizuoka Amagisan 210 04 Shizuoka Umegashima 202 05 Shizuoka Ikawa 201 05 Shizuoka Honkawane 201 2. Top-5 Peak Sustained Wind (10-min avg) Obs --------------------------------------------- Ranking Station Peak wind (mps) ------------------------------------------------------------------------ 01 Miyake-tsubota, Tokyo (JMA44228, Alt 20m) 30 [04/2030Z] 02 Chiba, Chiba (WMO47682, Alt 4m) #24.5 [04/2130Z] 03 Ojima, Tokyo (WMO47675, Alt 74m) #24.4 [04/2110Z] 04 Irouzaki, Shizuoka (WMO47666, Alt 55m) 24.3 [04/1950Z] 05 Haneda, Tokyo (JMA44166, Alt 6m) 24 [04/2140Z] 3. Peak Gust Obs (only those >= 40 m/s listed) ---------------------------------------------- Ranking Station Peak wind (mps) ------------------------------------------------------------------------ 01 Ojima, Tokyo (WMO47675, Alt 74m) #48.3 [04/2032Z] 02 Chiba, Chiba (WMO47682, Alt 4m) #47.8 [04/2141Z] 03 Katsuura, Chiba (WMO47674, Alt 12m) #43.7 [04/2208Z] 04 Yokohama, Kanagawa (WMO47670, Alt 39m) #43.4 [04/2050Z] 05 Irouzaki, Shizuoka (WMO47666, Alt 55m) #41.6 [04/1942Z] 06 Omaezaki, Shizuoka (WMO47655, Alt 45m) #41.3 [04/1936Z] 07 Choshi, Chiba (WMO47648, Alt 20m) #41.0 [04/2151Z] 08 Hachijojima, Tokyo (WMO47678, Alt 79m) 40.3 [04/2217Z] 09 Tokyo, Tokyo (WMO47662, Alt 6m) *#40.2 [04/2120Z] 4. Top-5 SLP Obs ---------------- Ranking Station Min SLP (hPa) ---------------------------------------------------------------- 01 Mito, Ibaraki (WMO47629) 974.4 [04/2155Z] 02 Tokyo, Tokyo (WMO47662) 975.6 [04/2116Z] 03 Takayama, Gifu (WMO47617) 976.1 [04/1906Z] 04 Utsunomiya, Tochigi (WMO47615) 976.2 [04/2142Z] 05 Yokohama, Kanagawa (WMO47670) 976.9 [04/2056Z] {Part III}. The most significant obs available to me from other prefectures =============================================================== Tomogashima, Wakayama (JMA65036, 34.28N 135.00E, Alt 43m) reported a peak sustained wind (10-min avg) of 31 m/s [04/1630Z] during the storm, while Shishikui, Tokushima (JMA71316, 33.56N 134.31E, Alt 4m) recorded a storm total rainfall of 269 mm [03/2200--04/1700Z]. {Part IV} References ==================== (Japanese version only)> (Japanese version) G. Michael Padua Observations from the Philippines -------------------------------------------------- Michael Padua in Naga City sent me the following observations he made during the passage of Typhoon Nanmadol/Yoyong to the north of his home: Closest approach to Naga City (13.6N/123.2E): 02/0530 UTC - 87 nm to the NNE Highest wind speed (presumably gust): 45 kts from south at 02/0727 UTC Minimum barometric pressure: 991.4 mb at 02/0529 UTC Highest rainfall rates: (1) 62.5 mm/hr at 02/0206 UTC (2) 90.4 mm/hr at 01/1326 UTC Rainfall storm total: 173.7 mm 30 November - 02 December (Report written by Kevin Boyle with significant contributions by Huang Chunliang and Michael Padua) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for November: 1 deep depression ** 1 severe cyclonic storm ++ ** - this system classified as a tropical storm by JTWC ++ - this system classified as a hurricane by JTWC Sources of Information ---------------------- Most of the information presented below is based upon tropical cyclone warnings and significant tropical weather outlooks issued by the Joint Typhoon Warning Center of the U. S. Air Force and Navy (JTWC), located at Pearl Harbor, Hawaii. Occasionally some information may be gleaned from the daily tropical weather outlooks and other bulletins issued by the Indian Meteorological Department (IMD), which is the World Meteorological Organization's Regional Specialised Meteorological Centre (RSMC) for the basin. The reported maximum sustained winds (MSW) are based on a 1-minute averaging period, which is used by all U. S. civilian and military weather services for tropical cyclone warnings. For synoptic observations in the North Indian Ocean region, both 10-minute and 3-minute average winds are employed, but IMD makes no attempt to modify the Dvorak scale for estimating tropical cyclone intensity; hence, a 1-minute average MSW is implied. In the North Indian Ocean basin JTWC usually does not initiate warnings until a system has become well-organized and likely to attain tropical storm status within 48 hours. North Indian Ocean Tropical Activity for November ------------------------------------------------- Two tropical cyclones came to life in the North Indian Ocean during the month of November, both in the Arabian Sea. The first one was classified as a minimal tropical storm by JTWC, but only as a deep depression by IMD. Tropical Cyclone 04A formed early in the month in the central Arabian Sea and moved generally in the direction of the Arabian Peninsula, later moving southwestward as it weakened and dissipated off the coast of Somalia. Late in the month Cyclonic Storm Agni formed at an extremely low latitude in the southern Arabian Sea, only 42 nm north of the equator. Furthermore, before the tropical storm developed, the parent circulation had drifted southwestward to a point just south of the equator and then moved back into the Northern Hemisphere while maintaining its counterclockwise circulation. Short reports on both these systems follow. TROPICAL CYCLONE (TC-04A) 4 - 7 November ------------------------------------ A STWO issued by JTWC at 1800 UTC on 31 October noted that an area of convection had developed and persisted approximately 750 nm west of Colombo, Sri Lanka. A 31/0106 UTC QuikScat pass had revealed the existence of a LLCC around which convection was beginning to organize, and upper-level conditions were favorable for further development with good diffluence and low vertical shear. The potential for development was upgraded to fair at 1300 UTC on 1 November as deep convection had continued to consolidate around the LLCC. A ship observation around 01/0600 UTC had reported maximum winds of only 10-15 kts, but in light of the increasing organization the MSW was estimated to have increased to 20-25 kts. At 02/1800 UTC the disturbance had moved westward to a point almost 900 nm west-northwest of Colombo and deep convection was continuing to cycle near the LLCC. At 0700 UTC on 4 November the system was located almost 500 nm south- west of Mumbai (Bombay), India, and the deep convection was becoming more wrapped around the LLCC. Animated water vapor imagery showed an increase in poleward outflow, and an upper-level analysis indicated that the LLCC was located in an environment of low to moderate vertical shear with favorable divergence aloft. Maximum winds were estimated at 25-30 kts, and the potential for development was upgraded to good with a TCFA being issued at this time. The first JTWC warning on Tropical Cyclone 04A was issued at 1200 UTC on the 4th, placing the center approximately 500 nm southwest of Mumbai. The initial warning intensity was set at 35 kts. Over the next couple of days TC-04A moved on a course slightly north of due west. The peak intensity of 40 kts was reached at 05/0600 UTC, and again for a 12-hour period beginning at 06/0000 UTC, based on satellite CI estimates of 35 and 45 kts. The system was in an environ- ment of weak vertical shear and poleward outflow, but deep convection remained confined to the eastern semicircle. The MSW was decreased to 35 kts at 1200 UTC on the 6th as satellite imagery revealed a fully- exposed LLCC located approximately 120 nm to the southwest of the remaining convection. After 07/0000 UTC, TC-04A began to move on a southwesterly track as it weakened. Deep convection had dissipated by 07/1200 UTC due to the entrainment of dry, continental air and the MSW was dropped to 25 kts. The final JTWC warning at 1800 UTC placed the still well-defined LLCC about 150 nm east of Socotra Island, or about 280 nm east-northeast of Cape Guardafui, Somalia. (This system was not treated as a cyclonic storm by IMD.) TC-04A seemed to stage a weak attempt at a comeback. A QuikScat chart at 0724 UTC on 9 November shows a circulation off the coast of Somalia with some possible rain-contaminated vectors exceeding 50 kts, and a visible image at 09/0500 UTC depicts a flare-up of convection associated with the system. No damage or casualties are known to have resulted from this rather weak marine cyclone. (Report written by Gary Padgett) SEVERE CYCLONIC STORM AGNI (ARB0403 / TC-05A) 28 November - 3 December ---------------------------------------------- Agni: contributed by India, means 'fire' A. Storm Origins ---------------- The origins of Agni are in a sense more exciting than the cyclonic storm stage which followed. As early as 19 November an area of convection developed and persisted at an unusually low latitude (2.7N) about 445 nm east-southeast of Colombo, Sri Lanka. Animated multi- spectral imagery and an 18/1235 UTC QuikScat pass showed that convection was beginning to consolidate around a well-defined LLCC. Concurrently, an upper-level analysis indicated that the region was under moderate vertical shear but also in a region of favorable divergence. Maximum winds were estimated at 20 kts. Over the next few days the rather broad LLCC drifted westward, passing approximately 250 nm south of Colombo on the 21st. Deep convection seemed to be increasing on the 22nd so the development potential was upgraded to fair. JTWC issued a TCFA for the system at 2200 UTC on 22 November, placing the center about 255 nm southwest of Colombo and estimating the maximum winds at 25-30 kts. However, 24 hours later the convection had decreased and had become cyclic, so the TCFA was cancelled and the potential for development downgraded to poor. The disturbance was written off as a candidate for tropical cyclone development on the 24th. Another area of convection had developed by 1800 UTC on 26 November about 560 nm southwest of Colombo, or only 90 nm north of the equator. This area of disturbed weather was likely a continuation of the earlier system described in the above paragraph. Animated infrared imagery indicated that deep convection was becoming organized over a weak LLCC. An upper-level analysis indicated low vertical shear and good diffluence aloft. The maximum winds were estimated at 20-25 kts and the development potential was assessed as fair. At 1800 UTC on the 27th the disturbance was located farther to the west, or about 620 nm west-southwest of Colombo. JTWC issued a TCFA for the system at 0300 UTC on 28 November due to increasing deep convection over the LLCC. Maximum winds were now estimated at 25-30 kts. The first JTWC warning on Tropical Cyclone 05A was issued at 0600 UTC on 28 November, placing the center approximately 785 nm west-southwest of Colombo, or over 1100 nm south-southwest of Mumbai, tracking west at 10 kts. The initial warning intensity of 35 kts was based on CI estimates of 35 and 45 kts. The initial warning location of TC-05A's center was only 42 nm north of the equator! The lowest latitude system so far to date was Typhoon Vamei in December, 2001, which was a typhoon only 90 nm north of the "line". However, even more astounding is a QuikScat image taken of the pre-warning circulation at 27/0107 UTC. This image clearly shows a broad, somewhat elongated circulation with a COUNTERCLOCKWISE spin centered about a half-degree SOUTH of the equator! It appears that this system of Northern Hemisphere origin dipped just south of the equator and then came back without losing its counterclockwise rotation. It would be a pretty good bet to say that this is the first documented case of such an occurrence. B. Synoptic History ------------------- Having apparently survived its excursion just south of the equator, the tropical cyclone embarked on a generally northwestward track across the Arabian Sea which it would follow for most of its life. At some point IMD named the system Cyclonic Storm Agni, but I am not certain of the exact time the storm became the second officially named North Indian Ocean tropical cyclone on record. Once having reached tropical storm intensity, Agni continued to intensify rather steadily. By 1200 UTC on 29 November JTWC had upped the MSW to 65 kts, based on CI estimates of 55 and 65 kts. The size of the CDO had decreased slightly, but outflow remained well-defined in all directions. At this time Agni was located about 1050 nm south-southwest of Mumbai, or approximately 920 nm east- southeast of Cape Guardafui, Somalia. Based upon JTWC's warnings, Agni maintained hurricane intensity for 18 hours before beginning to slowly weaken. Continued weakening was forecast as Agni was moving into a region of moderate vertical shear and drier air. The MSW was lowered to 40 kts at 0000 UTC on 2 December when the storm was centered approximately 375 nm southeast of Cape Guardafui. Satellite CI estimates at the time ranged from 35 to 45 kts. Agni was by now moving on more of a westerly course as it tracked along the southern periphery of the subtropical ridge. Deep convection continued to cycle over the storm as it continued plodding toward the Somalian coastline. This apparently led to some satellite analysts assigning Dvorak ratings as high as T3.5, but JTWC maintained the MSW at 40 kts during this period. However, by 03/1800 UTC CI estimates had dropped to 25 and 35 kts, and with the system having encountered a hostile environment of dry, continental air and reduced outflow, JTWC issued the final warning on Agni, locating the weakening 30-kt center about 240 nm south-southeast of Cape Guardafui. C. Further Discussion --------------------- Regarding the maximum intensity of Severe Cyclonic Storm Agni, Karl Hoarau feels that early on 30 November the intensity could have been as high as 80-85 kts. According to Dr. Hoarau, the Dvorak embedded center technique with the EIR imagery would have yielded Data-T numbers of 4.5 or 5.0. Also, microwave images showed a much better signature with an eye at 30/0239 UTC, which was not the case on the 29th. I do not know the maximum intensity assigned Agni by IMD, but I do have a copy of an IMD warning for 30/1200 UTC which estimates the MSW at 55 kts and forecast to increase to 65 kts in six hours. This is the basis for my referring to the system as Severe Cyclonic Storm Agni in the title line above. D. Damage and Casualties ------------------------ There are no known damage or casualties resulting from Severe Cyclonic Storm Agni. (Report written by Gary Padgett) ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for November: 1 severe tropical storm ** 1 very intense tropical cyclone ** - this system classified as a minimal hurricane (cyclone) by JTWC Sources of Information ---------------------- The primary sources of tracking and intensity information for Southwest Indian Ocean tropical cyclones are the warnings issued by the Tropical Cyclone Warning Centre on La Reunion Island, part of Meteo France (MFR), and the Regional Specialised Meteorological Centre for the basin. However, tropical cyclones in this region are named by the sub-regional warning centres on Mauritius and Madagascar with longitude 55E being the demarcation line between their respective areas of warning responsibility. The La Reunion centre only advises these agencies regarding the intensity of tropical systems. References to sustained winds imply a 10-minute averaging period unless otherwise stated. In the companion tropical cyclone tracks file, I occasionally annotate positions from warnings issued by the Joint Typhoon Warning Center (JTWC) of the U. S. Air Force and Navy, located at Pearl Harbor, Hawaii, when they differ from MFR's coordinates by usually 40-50 nm or more. The JTWC warnings are also the source of the 1-minute average maximum sustained wind values included in the tracks file. Additionally, information describing details of satellite imagery and atmospheric circulation features included in the narratives is often gleaned from the JTWC warnings. Southwest Indian Ocean Tropical Activity for November ----------------------------------------------------- The first two named tropical cyclones of the Southern Hemisphere season formed in the Southwest Indian Ocean basin during November. Both formed well to the east of Diego Garcia and equatorward of latitude 10S. Arola became a severe tropical storm with peak winds reaching 60 kts, but Bento became the most intense Southwest Indian cyclone to form north of 10S--the cyclone reached its peak intensity of 120 kts at latitude 8.5S. Both systems passed south of Diego Garcia but at a sufficient distance that there were no significant effects felt on the island. Reports on both Arola and Bento follow. SEVERE TROPICAL STORM AROLA (MFR-03 / TC-03S) 7 - 13 November ----------------------------------------------- Arola: contributed by Lesotho A. Storm Origins ---------------- Early on 7 November (UTC) an area of convection lay approximately 630 nm east-northeast of Diego Garcia. Animated infrared satellite imagery revealed a mid-level circulation becoming more organized over a possible weak LLCC. An upper-level analysis indicated moderate diffluence in the poleward direction with weak to moderate vertical shear under the subtropical ridge axis. MFR initiated bulletins on Tropical Disturbance 03 at 07/0600 UTC with a very weak 15-kt center located about 650 nm east of Diego Garcia. Deep convection continued to persist near the LLCC and the winds were increased to 25 kts at 1800 UTC. JTWC issued a TCFA for the system at 0200 UTC on 8 November as the system continued to display increased organization. B. Synoptic History ------------------- The system continued to increase in organization and at 0600 UTC on 8 November MFR upgraded the disturbance to tropical depression status, i.e., 30-kt winds. (At the same time JTWC issued the first warning on TC-03S with the 1-min avg MSW estimated at 35 kts.) Six hours later MFR upgraded the depression to tropical storm status with Mauritius assigning the name Arola. Tropical Storm Arola was then located about 400 nm east-southeast of Diego Garcia with the MSW estimated at 45 kts (10-min avg). Arola was moving west-southwestward and this motion was forecast to continue as the system remained under the steering influence of an anticyclone anchored to the south of the storm. Arola continued to intensify rapidly on the 8th of November--by 1800 UTC the storm had reached its peak intensity of 60 kts, increasing from 30 kts in only 12 hours. The minimum CP estimated by MFR was 976 hPa. At this point Arola exhibited a very strong poleward outflow channel. Surface inflow also was strong with feeder bands stretching over 300 nm equatorward from the center. Severe Tropical Storm Arola maintained its 60-kt intensity for 24 hours, then began to slowly weaken. By 09/1800 UTC convection had decreased and the center had become partially-exposed. "Slowly" describes Arola in two ways on the 10th through 12th of November--it very slowly weakened and also moved very slowly, generally in a west- southwesterly direction. The MSW had dropped to 45 kts by 1200 UTC on the 10th, and to minimal tropical storm intensity of 35 kts 24 hours later. At 12/0600 UTC Arola was downgraded to a 30-kt tropical depression while located approximately 285 nm south-southeast of Diego Garcia. The weakening depression continued to drift westward for the next day or so--the final bulletin on the system at 13/1200 UTC placed the center about 400 nm southwest of Diego Garcia. The peak intensity estimated by JTWC was 75 kts (1-min avg) at 0000 UTC on 9 November, up from 45 kts six hours earlier. This was based on CI estimates of 65 and 77 kts. However, six hours later the MSW was dropped to 65 kts. Satellite imagery revealed that the convection had greatly weakened and that the eye had disappeared. This sharp increase in the reported winds and subsequent quick reduction suggests that perhaps the 75-kt estimate at 09/0000 UTC was a little high. C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Severe Tropical Storm Arola. (Report written by Gary Padgett) VERY INTENSE TROPICAL CYCLONE BENTO (MFR-04 / TC-04S) 20 - 30 November ------------------------------------------------------- Bento: contributed by Mozambique A. Storm Origins ---------------- An area of convection developed and persisted on 18 November roughly 365 nm east of Diego Garcia. Animated multi-spectral imagery and data from an 18/1240 UTC QuikScat pass revealed that convection was beginning to consolidate around a well-defined and elongated LLCC. An upper-level analysis indicated low to moderate vertical shear and favorable divergence aloft, and an increase in 850-mb vorticity had also been noted. The disturbance drifted westward and 24 hours later was located approximately 310 nm east of Diego Garcia. MFR began issuing bulletins on the developing disturbance at 0600 UTC on 20 November, designating it as Tropical Disturbance 04 and locating the center about 300 nm east of Diego Garcia with winds estimated at 25 kts, locally 30 kts in the southern quadrants. Convection gradually increased in organization near the LLCC and the upper-level environment remained favorable for strengthening. The system was upgraded to a 30-kt tropical depression at 21/0000 UTC when located approximately 325 nm slightly south of due east of Diego Garcia. B. Synoptic History ------------------- JTWC initiated warnings on TC-04S at 21/0600 UTC, and six hours later the system became Tropical Storm Bento, located about 375 nm east- southeast of Diego Garcia with 40-kt winds (10-min avg). Bento steadily increased in intensity, reaching cyclone (i.e., hurricane) status by 1200 UTC on 22 November when located about 300 nm east-southeast of Diego Garcia. Interestingly, at 1800 UTC on the 21st satellite CI estimates were ranging from 45 to 77 kts. Bento was similar to its predecessor Tropical Storm Arola in two regards: (1) it moved rather slowly, most of the time around 5 kts or less, and (2) it intensified rather quickly to its peak intensity and then weakened slowly for several days. However, the similarity ends there as Bento was much more intense than Arola. Once having reached cyclone intensity at 22/1200 UTC, Bento deepened very rapidly, reaching its peak intensity of 120 kts within 24 hours. The very intense cyclone was at this time located about 175 nm east-southeast of Diego Garcia, at latitude 8.5S. According to Karl Hoarau, Bento is the first South Indian cyclone on record to reach this extreme intensity equatorward of 10S. JTWC's estimated peak 1-min avg MSW of 140 kts compares very well with MFR's intensity. All satellite agencies assigned a Dvorak rating of T7.0 to Bento on the 23rd. Bento was a somewhat compact tropical cyclone with gales covering an area only around 200 nm in diameter. The minimum CP estimated by MFR was 905 hPa. Tropical Cyclone Bento maintained its peak intensity of 120 kts for an 18-hour period, and then began to slowly weaken on the 24th. The initial weakening was likely due to an eyewall replacement cycle which was evident in satellite imagery. During its most intense phase Bento tracked slowly in a west-southwesterly direction under the steering influence of a subtropical ridge anchored to the south of the cyclone. Convection was beginning to decrease by 24/1800 UTC due to some dry air intrusion, and at 25/0000 UTC MFR lowered the MSW to 95 kts. By this time Bento had made a fairly abrupt turn to the south-southeast around the western periphery of the mid-level steering ridge toward a weakness created by a passing mid-latitude trough. In addition to the dry air the cyclone was moving into a region of increasing vertical shear. By 1800 UTC on 25 November the MSW had dropped to 70 kts, and six hours later MFR downgraded Bento to a tropical storm, located about 350 nm south-southeast of Diego Garcia. The weakening Bento continued to track slowly in a general south- southeasterly direction for the next few days. The storm's intensity, based on MFR's analysis, remained pegged around 50-55 kts for a three- day period from the 26th through 28th, and JTWC's 1-min avg MSW estimates were in general agreement. However, there is some evidence that Bento may have been stronger than this on the 27th and 28th. Two consecutive QuikScat passes over the cyclone--one at 27/1211 UTC and the other at 28/0040 UTC--show winds of up to 75 kts or stronger. According to Roger Edson it is highly unlikely that these winds are artificially too high. The satellite agencies were all reporting Dvorak ratings of T3.0 and T3.5 around this time. In Roger's opinion the CI was not behaving the way it is "supposed" to, and he considered this very possible since Bento had a large wind field and could possibly take longer than normal to wind down. By late on the 27th the LLCC had become decoupled from the deep convection and by 28/0600 UTC the center had become fully-exposed. Convection continued to decrease, and JTWC issued their final warning on Bento at 0600 UTC on 29 November. The LLCC was drifting westward while the sheared convection was tracking southeastward. MFR downgraded Bento to a tropical depression at 29/1200 UTC--the system was then located approximately 575 nm south-southeast of Diego Garcia. The system continued to weaken and the final bulletin was issued at 1200 UTC on the 30th, placing the center about 615 nm south of Diego Garcia. The MSW had decreased to 25 kts but winds up to 30 kts were still considered possible in isolated locations in the southern semicircle. C. Damage and Casualties ------------------------ Tropical Cyclone Bento remained well-removed from any populated regions during its lifetime and there have been no reports of damage or casualties resulting from the storm. (Report written by Gary Padgett) ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for November: No tropical cyclones ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for November: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for November: No tropical cyclones ************************************************************************* SPECIAL FEATURE - SOURCES OF TROPICAL CYCLONE INFORMATION The purpose of this section is to list some websites where many and varied types of tropical cyclone information are archived. Many readers will know about these already, but for the benefit of those who don't, I wanted to include them. (1) Aircraft Reconnaissance Information --------------------------------------- Various types of messages from reconnaissance aircraft may be retrieved from the following FTP site: Information regarding how to interpret the coded reconnaissance messages may be found at the following URL: Links are also included to websites with further information about the U. S. Air Force 53rd Weather Reconnaissance Squadron and the NOAA Air- craft Operations Center. (2) Archived Advisories ----------------------- All the advisory products (public advisories, forecast/advisories, strike probabilities, discussions, various graphics) issued by TPC/NHC are archived on TPC's website. For the current year (using 2004 as an example), the archived products can be found at: Links to tropical products archives for earlier years are available at the following URL: JTWC warnings for past storms are archived on the NRL Monterry website: On the NRL site, the link to past years can be found in the upper left corner of the screen. I am not aware at the moment of any other TCWC which archives all its tropical cyclone warning/advisory products for public access, but if I learn of any, I will add them to this list. (3) Satellite Imagery --------------------- Satellite images of tropical cyclones in various sensor bands are available on the NRL Monterrey and University of Wisconsin websites, courtesy of Jeff Hawkins and Chris Velden and their associates. The links are: On the NRL site, the link to past years can be found in the upper left corner of the screen. For the CIMSS site, a link to data archives is located in the lower left portion of the screen. I'm sure there are other sites with available imagery available, and as I learn of them, I will add the links to this list. ************************************************************************* 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 August, 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 from the archive sites listed below. (Note: I do have a limited e-mail distribution list for the track files. If anyone wishes to receive these via e-mail, please send me a message.) 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. Back issues can be obtained from the following websites (courtesy of Michael Bath, Michael V. Padua, Michael Pitt, Chris Landsea, and John Diebolt): 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 Annual Tropical Cyclone Report (ATCR) for 2004 (2003-2004 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 2004 Atlantic and Eastern North Pacific tropical cyclones; also, storm reports for all the 2004 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 Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South China Sea) E-mail: newchapelobservatory@btinternet.com John Wallace (Assistance with Eastern North Pacific) E-mail: dosidicus@aol.com Huang Chunliang (Assistance with Western Northwest Pacific, South China Sea) E-mail: huangchunliang@hotmail.com Simon Clarke (Northeast Australia/Coral Sea, South Pacific) E-mail: saclarke@iprimus.com.au ************************************************************************* ************************************************************************* Uploaded: 03.27.05 / Typhoon2000.ph, Typhoon2000.com