GARY PADGETT'S MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY OCTOBER, 2003 (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.) ************************************************************************* OCTOBER HIGHLIGHTS --> Sluggish Gulf of Mexico tropical storm affects southern Mexico --> Eastern Pacific storms affect Mexican West Coast --> Year's fourth super typhoon forms in Western Pacific--executes large clockwise loop --> Minimal typhoon strikes Luzon ************************************************************************* ***** Feature of the Month for October ***** INTENSE VERY LATE-SEASON CARIBBEAN HURRICANES The following monthly feature is a condensation of a paper presented at the 25th AMS Conference on Hurricanes and Tropical Meteorology in San Diego in 2002. The author of the paper is Rich Henning of the 53rd Weather Reconnaissance Squadron, Keesler AFB, Mississippi, and who is also a staff meteorologist at Eglin AFB, Florida. A special thanks to Rich for giving me permission to feature his paper and for proofreading it. A. Introduction --------------- The four Atlantic hurricane seasons of 1998-2001 have produced a climatologically unprecedented surge in very late-season, intense tropical cyclone (TC) development over the Caribbean Sea. Since 1950, only six TCs have undergone rapid intensification (RI) into very intense (Category Four or higher on the Saffir/Simpson scale) hurricanes after 20 October. Of those six, three have occurred since October of 1998. The following table lists these six hurricanes which will be examined in the following discussion: Storm/Year Dates and Amount of RI CP MSW ----------------------------------------------------------------------- Fox, 1952 22-24 Oct, 59 mb in 48 hrs 934 mb 130 kts Hattie, 1961 28-30 Oct, 71 mb in 54 hrs (1) 920 mb 140 kts Joan, 1988 21-22 Oct, 38 mb in 24 hrs 932 mb 125 kts Mitch, 1998 24-26 Oct, 85 mb in 60 hrs (2) 905 mb 155 kts Lenny, 1999 16-17 Nov, 49 mb in 42 hrs (3) 933 mb 135 kts Michelle, 2001 02-03 Nov, 38 mb in 18 hrs 933 mb 120 kts Notes: (1) 36 mb in 18 hrs (2) 54 mb in 24 hrs (3) 34 mb in 24 hrs (4) 1952 and 2001 were neutral ENSO years; the remainder of the above storms occurred in cold ENSO (La Nina) years. The climatological peak of the Atlantic hurricane season occurs around 10 September, so 20 October falls well after the normal seasonal peak, both in terms of the frequency of storms and their destructive potential. In most years, with the exception of a few extreme climatological outliers (i.e., Kate of 1985), the onset of strong upper-level westerlies north of the Tropic of Cancer at some point during the month of October effectively ends the risk of any U. S. landfalling major hurricanes. However, deeper in the tropics during some seasons, extraordinarily favorable conditions can become established and persist in the Caribbean Sea well into the month of November. In fact, the most favorable conditions, both in terms of thermodynamic and dynamic factors at any time during the entire season (June through November) in the Atlantic/Caribbean Basin occurred in the Caribbean Sea after 20 October during the six seasons listed above. B. Discussion ------------- One thing all the six storms examined had in common was that they intensified beneath a persistent, very high-amplitude 200-mb anti- cyclone. Such features are only likely to develop near the end of hurricane seasons associated with either cold ENSO (La Nina) or neutral conditions. Such anticyclones are seldom found during warm ENSO (El Nino) events. All six of the subject hurricanes except for Joan of 1988 formed in the monsoon trough which typically migrates into the southwestern Caribbean at some point during October. Hurricane Joan was an anomalously late-season Cape Verde system which formed in the central Atlantic near 45W but did not reach hurricane intensity until it had reached the southwestern Caribbean after transiting the northern coasts of Venezuela and Colombia. Joan did not explode into a major hurricane until it moved beneath a large 200-mb ridge axis, but when it did undergo RI just off the Nicaraguan coast (38 mb in 24 hours on 22 October, 1988) the rate of intensification was extreme and only its movement over Central America prevented its central pressure from likely dropping even lower than the 932 mb recorded at landfall. It is interesting to note that while mighty Hurricane Gilbert a few weeks earlier turned out to be a much more powerful storm (888 mb), it could be argued that Joan enjoyed a more favorable upper-level environment. An examination of upper-air charts shows a closed 100-mb anticyclone over Joan during its RI event. Studies by Halverson, Simpson, et al (1999) and Henning (2000) have suggested that some RI events may be triggered by convective-scale processes high within the inner core as outflow from adjacent, very tall, cumulonimbus towers converges. This, along with the collapse of these convective towers, may help trigger the extreme subsidence associated with rapid eye formation. The existence of a 100-mb closed anticyclone centered above the TC core would provide the perfect dynamic environment for this process to occur at levels just above the tropopause near 16 km. Rapid eye formation subsequent to an unusually deep burst of core convection and convective collapse was the signature of Hurricanes Mitch (1998), Lenny (1999) and Michelle (2001). Such idealized vertical stacking of the atmosphere from the surface to above the tropopause seldom occurs anywhere else in the Atlantic Basin, even during what is commonly thought of as the "heart" of the hurricane season (August and September). Instead, it is a feature more likely to be seen in the interval of late October through early November in the western Caribbean, but only during cold or neutral ENSO events. The 2000 and 2001 Atlantic hurricane seasons were characterized by many rapidly translating TCs carried westward by strong lower tropo- spheric flow. The resulting "bottom up" shear inhibited the develop- ment of several TCs that otherwise appeared to be good candidates for significant intensification. A case in point was Chantal, which transited the western Caribbean during the climatologically favorable period of late August and was expected to be a good candidate for RI, but the vortex never slowed down long enough to allow Chantal to become even a minimal hurricane. Another factor which permits these very late-season TCs to become major hurricanes in this area is the absence of these low-level easterly wind bursts. Storms like Mitch and Michelle were able to "park themselves" beneath favorable upper- level synoptic regimes long enough for mesoscale and convective processes in the core region to unfold and allow the process of RI to take place. Thermodynamically speaking, conditions in the western Caribbean are always better than anywhere else in the Atlantic Basin, and these are usually optimal in late October. Upper-oceanic heat content is very high in this region, and with deep thermoclines present, developing TCs can sit over a given location for days without the combination of mixing and upwelling significantly reducing thermo- dynamic potential, as would be the case in most other areas in the Atlantic Basin. Also, by late October the tropopause has normally cooled a few degrees from mid-summer values, and with the high upper- oceanic heat content, the thermodynamic potential is maximized over the western Caribbean during this time of year. During cold or neutral ENSO years, identifying the conditions discussed in this paper may aid in determining whether or not the required synoptic-scale prerequisites for a very late-season Caribbean RI event are in place. However, before forecasters can reliably predict whether or not such an event will actually occur, more research needs to be done into the smaller scale convective and mesoscale processes in the TC core/eyewall region which ultimately dictate their occurrence or non-occurrence. C. References ------------- Halverson, J. B., et al, 1999: First TRMM satellite observations of a deep convective burst in Supertyphoon Paka (1997). Preprints, 23rd Conference on Hurricanes and Tropical Meteorology, AMS, Dallas, TX, 997-1000. Henning, R. G., 2000: Observations of low-level wind maxima using GPS dropsondes and their link to 200-millibar clues identifying the onset of rapid intensification. Preprints, 24th Conference on Hurricanes and Tropical Meteorology, AMS, Fort Lauderdale, FL, 250-251. D. Contact Information ---------------------- Rich can be contacted at the following addresses: Major Richard G. Henning 53rd WRS 817 H Street - Suite 134 Keesler AFB, MS 39434-2451 E-mail: richard.henning@eglin.af.mil ************************************************************************* ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for October: 3 tropical storms 3 hybrid LOWs 1 major hurricane ** ** - storm formed in September but reached intense hurricane status in early October Atlantic Tropical Activity for October -------------------------------------- The 1950-2002 averages for the month of October are 1.64 named storms, 1.08 hurricanes, and 0.34 intense hurricanes. October, 2003, produced 3 named storms, 0 hurricanes, and 1 intense hurricane. This unusual distribution is due to the fact that Hurricane Kate, which began in September, did not reach Category 3 status until 3 October. Kate peaked at 110 kts but fortunately remained in the central Atlantic and did not affect any populated areas. Tropical Storm Larry formed in the Bay of Campeche and remained slow-moving, eventually moving southward into the Mexican coast. Mindy was a short-lived minor storm which formed from a tropical wave near the eastern tip of the Dominican Republic and subsequently moved northward and northeastward. Nicholas formed about halfway between the Lesser Antilles and Africa around mid-month and moved slowly northwestward for over a week, almost reaching hurricane intensity at one point. Brief reports on the three October named storms can be found below and contain the links to the official TPC/NHC storm reports for the individual cyclones. There were also several interesting systems during October which did not warrant the issuance of advisories, but which nonetheless were of some interest. The first was a low-pressure center which formed off the southeastern U. S. coast during the second week of October and moved rather rapidly northeastward. The LOW was east of Cape Hatteras late on the 10th and was accompanied by a significant amount of convection east-northeast of the center. The system was treated as a gale in OPC marine warnings, although David Roth of HPC indicated that he didn't see any gale-force winds plotted on the OPC maps. The system had become frontal by the 12th, and the LOW subsequently became a large storm in the North Atlantic on 14-18 October with pressures falling to around 980 mb. The second system displaying hybrid-like features formed on 14 October east-southeast of Bermuda. By the morning of the 15th the system had moved northeastward and was located between Bermuda and the Azores. At this time I noticed that the LOW appeared to have some features of a subtropical cyclone, so I e-mailed a query to David Roth. David replied that the system could be classed as a frontal hybrid--a MCS blew up over and north of the LOW's warm front. The system appeared somewhat organized on 17 October with an eye-like feature in the middle of a ring of shallow convection, but by the evening of the 18th no convection remained near the center. The peak winds reported in the track sent by David, based on ship reports, were 30 kts. The third interesting system formed northeast of the Bahamas in late October. In its early stages it was associated with the remnants of former Tropical Storm Nicholas. The official TPC/NHC storm report now indicates that this LOW absorbed the extratropical remnants of Nicholas. The system moved westward, crossing southern Florida into the Gulf of Mexico, and finally making landfall along the north-central Gulf Coast on 5 November. Occasional bursts of convection accompanied the LOW, and gusts to gale-force were recorded in southern Florida. After the system entered the Gulf of Mexico, development into a subtropical or tropical storm was considered a possibility. Because of its association with Nicholas' remnants, there was some debate at NHC as to whether its name would be Nicholas or Odette in case advisories were required. It was finally determined that the association with Nicholas was rather tenuous, and that if a name were required, it would be Odette. Some time ago David Roth reported that he'd learned from Jack Beven that this system might be reclassified as an unnumbered depression. One final Atlantic tropical system--the Tropical Weather Outlook issued at 0930 UTC on 16 October mentioned a small low pressure system located roughly 500 nm west-southwest of the Cape Verde Islands. The LOW appeared to be fairly well-organized, and on the 17th was accompanied by winds of 20-25 kts, but did not have enough organized convection to be considered a tropical cyclone. Upper-level winds were not favorable for further development and the system had weakened by the 19th. The official TPC/NHC storm reports are all now available online, so I have not written the usual more detailed preliminary reports. Links to the reports can be found below with the brief discussion of each named tropical storm. TROPICAL STORM LARRY (TC-17) 30 September - 6 October -------------------------------------------- Tropical Storm Larry was a sluggish-moving storm which formed in the Bay of Campeche at the first of October from the interaction of a westward-moving tropical wave and a cold front. The wave had nearly developed into a tropical depression before making landfall along the eastern coastline of the Yucatan Peninsula, but when the LOW center redeveloped in the Bay of Campeche, cooler and drier air had been drawn into the system, giving it more of the character of an extra- tropical LOW, at least in the lower levels. The pressure gradient between the LOW and a strong HIGH over the northwestern Gulf created gale-force winds over a wide area of the southwestern Gulf of Mexico. After a couple of days convection had increased around the LLCC, warming and moistening the airmass. By late on 1 October the system had taken on sufficient tropical characteristics to be reclassified as Tropical Storm Larry. Any movement of the tropical cyclone northward was blocked by strong HIGH pressure to the north, so the system moved slowly and erratically for a few days, eventually drifting southward and moving inland in Mexico near Paraiso in the state of Tabasco. The peak intensity hovered around 50 kts for several days. The Best Track file in the online storm report now gives the peak MSW as 55 kts for one six-hour period. The remnants of Larry eventually moved into the Eastern Pacific as a non-convective remnant LOW, but no redevelopment occurred in that basin. Tropical Storm Larry's rains brought some flooding to the Isthmus of Tehuantepec. According to the NHC report, there were five fatalities in Mexico attributable to Larry. Some additional information on Larry's effects in Mexico can be found at the following URL: The official TPC/NHC storm report, written by Stacy Stewart, can be accessed at the following link: TROPICAL STORM MINDY (TC-18) 10 - 14 October ---------------------------------------- Tropical Storm Mindy was perhaps the most inconsequential tropical storm of the active 2003 Atlantic hurricane season. The system formed abruptly into a minimal tropical storm from a tropical wave on the 10th of October near the northeastern tip of Hispaniola. Mindy intensified to only 40 kts as it moved northward, skirting the Turks and Caicos Islands. Mindy's entire life was spent in an environment of fairly significant southwesterly or westerly shear, and by late on the 12th had weakened back into a tropical depression. The weakening system then turned east-northeastward ahead of an approaching shortwave trough and had deteriorated into a remnant LOW by the 14th. The official TPC/NHC storm report on Mindy, authored by Miles Lawrence, can be found at the following URL: TROPICAL STORM NICHOLAS (TC-19) 13 - 23 October ------------------------------------------- Tropical Storm Nicholas was the last storm of the Atlantic hurricane season to form in the main development region from a tropical wave. The cyclone spent its life in an environment of southwesterly shear which did not allow Nicholas to attain hurricane intensity. However, the storm came close to reaching hurricane status, peaking at 60 kts on 17 October. Nicholas moved slowly generally northwestward or west-northwestward for several days while located several hundred miles to the east of the Lesser Antilles. The system weakened to a tropical depression on the 23rd well to the east of the Leeward Islands and had become more or less an extratropical LOW by later that day. Nicholas' history as an extra- tropical system was rather interesting. It made a large anticyclonic loop southeast of Bermuda, then moved westward, making another loop northeast of the Bahamas, and was finally absorbed into another LOW which subsequently tracked westward across Florida and into the north- central Gulf Coast. (See introductory section above for more information on this system.) The official TPC/NHC storm report, written by Jack Beven, is available at the following link: ************************************************************************* NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180 Activity for October: 3 hurricanes Northeast Pacific Tropical Activity for October ----------------------------------------------- Every month thus far in the Northeast Pacific (except for May) saw below-normal tropical cyclone activity, but October, 2003, rebounded with a burst of three hurricanes which brought the seasonal number of named storms and hurricanes to normal levels. The 2003 season, however, still remains as the first since 1977 not to have produced an intense hurricane. The average numbers of named storms, hurricanes, and intense hurricanes for the basin over the 1971-2002 period are 2.00, 1.16, and 0.63, respectively. October saw the formation of three named storms, all of which reached hurricane intensity. Hurricane Nora was the strongest, peaking at 90 kts. Nora made landfall along Mexico's West Coast but only after weakening to tropical depression status. Olaf reached minimal hurricane intensity, weakened significantly, then recovered and made landfall in Mexico as a fairly strong tropical storm. The final hurricane, Patricia, remained well offshore as it pursued a westerly trajectory south of the Mexican coastline. The official TPC/NHC storm reports for all the cyclones are now available online. A brief report for each storm follows and contains the links to the official reports. HURRICANE NORA (TC-14E) 1 - 9 October ---------------------------------- Hurricane Nora formed south of the tip of Baja California from a tropical wave which had moved off the African continent a couple of weeks earlier. Nora moved northwestward while intensifying into a hurricane, then turned abruptly eastward while weakening to a tropical depression. The system made landfall in Mexico as a 25-kt depression on 9 October just north of Mazatlan and quickly dissipated. Nora was the third Eastern North Pacific hurricane of the season to reach an estimated peak intensity of 90 kts, and probably was the best-organized of the trio. Karl Hoarau performed a detailed Dvorak analysis of Nora and concluded that assigning a T-number of 5.5 around 1500 UTC on 4 October at least did not break any Dvorak constraints, and that in his opinion Nora could have possibly reached an intensity of 100 kts around that time. The official TPC/NHC storm report on Nora, written by Lixion Avila, is available at the following link: HURRICANE OLAF (TC-15E) 3 - 8 October ---------------------------------- Hurricane Olaf formed on the heels of Nora and operated concurrently with that cyclone. Some of the forecast scenarios included binary interaction between the two systems, but this never materialized. Olaf reached hurricane intensity briefly, then weakened significantly into a minimal tropical storm. After this, the storm recovered as it moved northward toward the Mexican coast, making landfall just west of Manzanillo as an intensifying 50-kt tropical storm. Olaf brought heavy rains to the states of Jalisco and Guanajuato. No deaths were reported, but considerable damage to homes, roads and crops was sustained. More information on the effects of Olaf in Mexico can be found at the following link: The official TPC/NHC storm report on Olaf, authored by Miles Lawrence, can be accessed at the following URL: HURRICANE PATRICIA (TC-16E) 20 - 26 October -------------------------------------- Like most of its predecessors, Hurricane Patricia formed from a tropical wave that had entered the Pacific after crossing Central American from the Caribbean. The season's final tropical cyclone developed quickly, being upgraded to a tropical storm on the second advisory, and reaching hurricane intensity only 24 hours after being classified as a tropical depression. Patricia followed an uncomplicated westerly track well off the southern Mexican coast, and unlike the preceding three cyclones, did not affect Mexico. The storm reached a peak intensity of 70 kts at 22/0000 UTC and began to weaken rather steadily thereafter. The official TPC/NHC storm report on Patricia, written by Richard Pasch, is available at the following link: ************************************************************************* NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180 Activity for October: 6 tropical depressions ** 2 typhoons ++ 1 super typhoon ** - Four of these numbered by JTWC--of these, one became a tropical storm in Bay of Bengal. Two systems classified as depressions by JMA only. ++ - One of these classified as a typhoon by JTWC only Northwest Pacific Tropical Activity for October ----------------------------------------------- The waters of the Northwest Pacific basin were quite active during the month of October. Three typhoons developed--Ketsana, Parma and Melor-- with Parma briefly becoming the year's fourth super typhoon. Ketsana and Parma remained at sea and did not significantly affect any islands. Melor struck northeastern Luzon in the Philippines but apparently was not destructive. Reports on all three typhoons are included below. Reports follow also on two tropical depressions which caused heavy rain- fall in Taiwan and Japan, respectively. One of these was unnumbered by JTWC, but the other was classified as a tropical depression by that agency and designated Tropical Depression 19W. The reports on both these depressions were sent by Huang Chunaling--a special thanks to Chunliang for compiling and sending the information. A special thanks also to Kevin Boyle for writing the reports on Typhoons Ketsana and Melor. In addition to these two tropical depressions, four other systems were classified as tropical depressions by various TCWCs. Tropical Depression 18W formed on 6 October in the northern South China Sea about 300 nm southeast of Hong Kong. This system was very slow-moving and meandered around in the South China Sea for several days. The final warning from JTWC at 10/0600 UTC placed the center 125 nm south of Hong Kong. The highest 1-min avg MSW reported by JTWC was 25 kts, but JMA carried the system for several days as a 30-kt depression. The Guangzhou Regional Meteorological Centre (GRMC) also briefly estimated the depression's intensity at 30 kts (10-min avg). The system had a very broad center and was difficult to track--there were numerous discrepancies in the center position as reported by the various warning centres. Tropical Depression 22W, named Ursula by PAGASA, formed on 22 October about 400 nm west-southwest of Manila. TD-19W/Ursula drifted generally eastward without any further development. The depression crossed northern Palawan Island and had reached the general area of Panay and Negros Islands before dissipating on the 24th. The final warning from PAGASA at 24/0000 UTC located the center about 300 nm south-southeast of Manila. PAGASA and JMA estimated TD-19W/Ursula's intensity (10-min avg) at 30 kts, but JTWC's highest reported MSW was only 25 kts. Tropical Depression 23W formed in the Gulf of Thailand on 23 October. This system eventually moved northwestward, crossing Thailand and emerging into the Bay of Bengal, where it became a minimal tropical storm before eventually making landfall in eastern India. Since this cyclone reached its peak intensity in the Bay of Bengal, the report is included in the section of this summary covering the North Indian Ocean basin. A low pressure system in the vicinity of 16N, 152E, well east of the Marianas, was classified as a weak tropical depression by JMA on the 16th of October. This LOW remained quasi-stationary and had weakened into a low-pressure area by the 17th. No track was included for this system in the accompanying tropical cyclone tracks file for October. TROPICAL DEPRESSION 5 - 7 October --------------------------------------- A. Synopsis ----------- JMA's High Seas Bulletin issued at 05/0000 UTC mentioned a weak tropical depression located about 450 nm southeast of the southern tip of Taiwan. Apparently there was a broad trough of low pressure in the region with several possible LLCCs. At 0600 UTC the system was relocated far to the west, southwest of Taiwan. Then, at 1200 UTC it was relocated well to the east to a position about 150 nm southeast of Taiwan's southern tip. The system remained in this vicinity for a day or two as it edged a little closer to Taiwan. At 06/1800 UTC the system had reached a point only about 35 nm southeast of the island. The final reference to the system was at 07/0000 UTC. Taiwan's Central Weather Bureau also treated the LOW as a tropical depression, issuing bulletins from 05/1800 UTC until 07/0600 UTC, when it was downgraded to a low-pressure area. JTWC never issued warnings on the system, but did issue a TCFA at 05/1700 UTC. The TCFA was subsequently cancelled at 06/1000 UTC when the system appeared to be weakening. B. Rainfall Observations ------------------------ The depression was responsible for some fairly significant rains on the island of Taiwan. Huang Chunliang compiled and sent the following rainfall information on this system. 1. WMO stations (only amounts > 50 mm are given): ------------------------------------------------- Station City/County Period (UTC) Rainfall -------------------- --------------- ------------------- --------- Ilan (WMO 46708) Ilan City 05/1600 - 06/1600 61.0 mm An Bu (WMO 46691) Taipei City 05/1600 - 06/1600 54.0 mm Suao (WMO 46706) Ilan City 05/1600 - 06/1600 50.5 mm 2. Automatic weather stations (only amounts > 100 mm are given): ---------------------------------------------------------------- CWB Station ID City/County Period Rainfall -------------------- --------------- ------------------- --------- C1U58 Ilan County 05/1600 - 06/1600 153.0 mm C0A55 Taipei County 05/1600 - 06/1600 122.5 mm C1U59 Ilan County 05/1600 - 06/1600 113.0 mm C1U69 Ilan County 05/1600 - 06/1600 103.5 mm C1A65 Taipei County 05/1600 - 06/1600 101.0 mm (Report written by Gary Padgett and Huang Chunliang) TROPICAL DEPRESSION (TC-19W) 12 - 13 October --------------------------------------- A. Introduction --------------- Tropical Depression 19W was a system which formed in subtropical latitudes and moved northeastward skirting the southern coast of Japan. It seems that JTWC was the only warning agency which classified this system as a tropical depression operationally. Huang Chunliang discovered a detailed report which JMA had prepared on this system and used it as a basis for a report which he sent me. Although treated as an extratropical LOW by JMA operationally, Chunliang notes that some Japanese websites referred to this system as a subtropical depression. The initial JTWC warning, issued at 12/0000 UTC, located the center approximately 180 nm south of Sasebo, Japan. Convection was building over a LLCC which had formerly been a weakening extratropical LOW, suggesting that transition to a warm-core system was taking place. TD-19W moved generally northeastward, skirting the southern coastlines of Shikoku and Honshu. A cold front was approaching from the northwest and overtook the LOW about the time it reached the coast of the main Japanese island of Honshu. The final JTWC warning was issued at 0000 UTC on 13 October. The center had moved inland south of Kyoto and weakened, and was located approximately 205 nm west-southwest of Tokyo. The remainder of this summary of TD-19W is based on the very detailed report prepared by Huang Chunliang. B. Daily Rainfall Observations ------------------------------ No WMO station reported a 24-hour total exceeding 100 mm. The highest daily total of any WMO station was 82.0 mm from Tokushima in Tokushima Prefecture (WMO 47895) during the period 11/1500 - 12/1500 UTC. Several JMA stations recorded 24-hourly amounts exceeding 100 mm: Station Prefecture JMA Code Alt (m) Rainfall (mm) ------------------------------------------------------------------------ Hakone Kanagawa 46161 850 126 Tomogashima Wakayama 65036 43 101 Ikegawa Kochi 74101 150 285 Fukuharaasahi Tokushima 71211 290 149 The first two entries were for the 24-hour period 12/1500 - 13/1500 UTC; the latter two for the 24 hours ending at 12/1500 UTC. The 285 mm at Ikegawa broke the former October record for daily rainfall amounts at the station. C. Peak Hourly Rainfall Observations ------------------------------------ The only WMO station to record an hourly rainfall exceeding 50 mm was Tokyo (WMO 47662). Between 0435 and 0535 UTC on 13 October the station recorded 57.5 mm of rain. Out of this amount, 19.0 mm fell during a 10-minute period, breaking the former October 10-minute rain- fall record at the station, the previous being 13.0 mm reported on 17 October 1987. Several JMA stations recorded hourly amounts exceeding 50 mm: Station Prefecture JMA Code Alt (m) Rainfall (mm) ------------------------------------------------------------------------ Edosaki Ibaraki 40391 25 56 Ryugasaki Ibaraki 40426 4 60 Nerima Tokyo 44076 38 53 Setagaya Tokyo 44126 35 57 Abiko Chiba 45056 20 61 Amikakeyama Nagano 48796 1120 58 Tomogashima Wakayama 65036 43 88 Ikegawa Kochi 74101 150 52 Nariyama Kochi 74176 737 57 Fukuharaasahi Tokushima 71211 290 53 D. Peak Wind Gust Observations ------------------------------ None of the stations listed by Chunliang reported sustained winds exceeding gale force. However, quite a few reported peak gusts in excess of 34 kts. These are tabulated below: Station Prefecture WMO Code Alt Date/Time Gust/Dir (m) (UTC) (kts) ----------------------------------------------------------------------- Tokyo Tokyo 47662 6 13/0516 36/NNW Ojima Tokyo 47675 74 13/0505 63/SW Hachijojima Tokyo 47678 79 13/0442 47/SW Miyakejima Tokyo 47677 36 13/0600 46/WSW Choshi Chiba 47648 20 13/0717 52/NW Tateyama Chiba 47672 6 13/0547 41/SW Katsuura Chiba 47674 12 13/0604 54/SSW Chiba Chiba 47682 4 13/0543 50/SW Yokohama Kanagawa 47670 39 13/0510 60/WSW Shizuoka Shizuoka 47656 14 13/0339 40/S Hamamatsu Shizuoka 47654 32 13/0447 36/W Omaezaki Shizuoka 47655 45 13/0317 57/SSW Mishimi Shizuoka 47657 21 13/0404 40/SW Irouzaki Shizuoka 47666 55 13/0426 53/SW Ajiro Shizuoka 47668 67 13/0426 39/WSW Irako Aichi 47653 6 13/0150 39/WSW Tsu Mie 47651 3 13/0158 53/NNW Wakayama Wakayama 47777 14 12/2316 40/N Shionomisaki Wakayama 47778 73 12/2330 50/SW Maitsuru Kyoto 47750 2 12/2210 35/NNE Hikone Shiga 47761 87 13/0148 39/NW E. Ship Reports --------------- Date/Time Lat / Lon Call Sign Wind Speed Direction (UTC) N / E (kts) ----------------------------------------------------------------- 10/0600 29.4 / 131.7 JPFT 38 ENE 10/0600 28.4 / 128.4 WDCJ 36 ENE 10/1800 27.3 / 129.4 JPFT 32 NE 11/0000 28.8 / 128.1 3EZF5 31 NE 11/0000 30.8 / 132.2 JGES 37 ENE 11/0300 28.7 / 130.5 9WCZ4 33 ENE 11/0600 30.7 / 130.4 ELWD5 31 E 11/0600 29.8 / 128.7 3ENO4 31 NNE 11/0600 29.7 / 130.7 JGES 31 E 12/0000 30.5 / 131.8 VNVF 36 SSE Note: Presumably these are 10-min avg sustained winds. F. Damage and Casualties ------------------------ Strong gusts triggered by TD-19W blew over cranes in two factories in Kamisu Town, Ibaraki Prefecture, during the afternoon of October 13, 2003, leaving two workers dead and several injuries. The strong wind knocked three steel cargo cars off 9-meter-high cranes at the Kashima plant of the metal-processing firm Sumikin Weld Pipe Company around 3:25 p.m. (JST) in Kamisu Town, Ibaraki Prefecture. A crane operator died about an hour later from injuries sustained after his car fell to the ground, while two others were thrown off but suffered only minor injuries. According to the company's anemometer, wind gusts were blowing as hard as 117 kts about 200 meters away from the site around the time the accident occurred. Separately, about three kilometers away at the Kashima steel mill of Sumitomo Metal Industries, Ltd--the parent company's iron works of Sumikin Weld Pipe Companies--two cargo cranes were struck with one of them toppling in the strong winds and falling on a cargo ship anchored beside it. Four other self-propelled cranes collided after being hit by the strong winds, injuring one operator. A gust up to 78 kts was observed there around 13/1525 JST. In Kamisu Town 9052 homes were without electrical power after 13/1520 JST. One of the anemometers in the town reported a peak gust of around 107 kts at 13/1523 JST. Another anemometer located by the Gulf of Kashima, near the two aforementioned factories, reported a peak gust of approximately 87 kts around 13/1530 JST. The last gust report from Kamisu Town came from Kashima also: a peak gust of approximately 78 kts was recorded by an anemometer (alt 20 m) located in a Kashima factory between 13/1500 JST and 13/1600 JST. After the on-the-spot investigations in the aftermath, the Tokyo District Meteorological Observatory concluded that downbursts triggered the strong gusts in Kamisu Town, Ibaraki Prefecture, and Narita City, Chiba Prefecture. According to their investigative report, the magnitudes of the downbursts occurring in the two areas were estimated at F1 (10-sec avg winds of 64 to 95 kts) to F2 (7-sec avg winds of 97 to 134 kts) and F1, respectively. It should be emphasized that both the downbursts fell into the spots near the real-time center of TD-19W. An F0 (15-sec avg winds of 33 to 62 kts) to F1 (10-sec avg winds of 64 to 95 kts) tornado occurred around 12/1000 JST, affecting a swath approximately 1200 metres long by 200 metres wide in Akano District, Aki City, Kochi Prefecture, with 19 houses being damaged. The agricultural losses there were estimated at 18,582 yen. The low-pressure system unleashed a brief but punishing torrent on quite a few regions in southern Japan, where damage to roadways, rail- ways, riverways and trees was reported as strong winds and heavy rains buffeted there, resulting in landslides, train delays, etc. There were at least two fatalities by drowning reported. G. References (Japanese Versions Only) -------------------------------------- This Special Report was distilled, translated and edited from the following JMA materials: TYPHOON KETSANA (TC-20W / TY 0317 / TISOY) 17 - 29 October ---------------------------------------------- Ketsana: contributed by Laos, is a kind of perfumed wood Tisoy: PAGASA name, is the Tagalog word for persons of mixed racial ancestry A. Storm Origins ---------------- Typhoon Ketsana developed from an area of convection located approximately 395 nm west-southwest of Guam, and was first noted in JTWC's STWO issued at 15/0600 UTC. The development potential was assessed as poor and remained so for several days as the broad LOW and its associated area of disorganised, cycling convection moved slowly to the west and west-northwest. By 0600 UTC on the 18th of October the complex LLCC had shifted to a position approximately 530 nm east of Manila, Philippines. The chances of a tropical cyclone developing were finally raised to fair at 18/0930 UTC, and then to good and a TCFA issued at 18/1300 UTC. At this time animated infrared satellite imagery revealed that a westerly wind burst was converging with and enhancing the broad LLCC, which was moving very slowly west-northwestward at 2 kts. The first warning on Tropical Depression 20W was issued soon afterward at 18/1800 UTC. B. Storm History ---------------- Tropical Depression 20W was located in the westernmost part of a large monsoon trough which also encompassed another disturbance on its eastern side. This system eventually became Typhoon Parma (TC-21W). TD-20W was moving very little at 18/1800 UTC while located approximately 450 nm south of Okinawa, but developed rapidly into a 35-kt tropical storm at 19/0000 UTC. Following JMA's upgrade to tropical storm status, the name Ketsana was introduced from the international naming list. (PAGASA's internal name was Tisoy.) Throughout the 20th and 21st movement was slow with only weak northeasterly steering currents controlling Ketsana. Intensification wasn't so slow, though, and at 20/1200 UTC Ketsana had outgrown its tropical storm phase and was upgraded to a 65-kt typhoon. The centre's location at this time was 775 nm southwest of Iwo Jima. Infrared satellite imagery began depicting an eye as the MSW reached 80 kts at 20/1800 UTC. This was backed up by a 20/1739 UTC AMSU pass which revealed a 16-nm eye. The ragged eye had expanded to 29 nm by 0000 UTC on 21 October. The storm's centre moved only 15 nm closer to Iwo Jima between 20/1200 and 21/0000 UTC. The slow motion continued throughout the day, as did strengthening. By 21/1200 UTC the MSW had reached 125 kts, just shy of super typhoon classification. However, intensification came to a halt at this point and 125 kts was to be Ketsana's peak intensity. Ketsana maintained this intensity for the rest of the day and into the 22nd, by which time it was moving a little more quickly toward the north or north-northeast at 4 to 6 kts. It also retained its symmetrical 20-nm eye, although some erosion was noted in the northeastern quadrant on a 22/0000 UTC microwave pass. Weakening began at 22/1800 UTC with the MSW falling to 115 kts, the eye now appearing in satellite images as a weak, ragged feature. At 23/0000 UTC Typhoon Ketsana was located approximately 600 nm west- southwest of Iwo Jima, moving slowly northeastward at 6 kts. The 30-nm eye had returned once more, but a weakening trend had set in with the intensity falling to 100 kts by 23/1800 UTC. A change was afoot the next day as the northeasterly motion began to accelerate and satellite imagery showed that shearing was beginning to elongate the northern part of the cloud pattern. Also, a mass of stratocumulus cloud was evident to the northwest of Ketsana, indicating the presence of colder, drier and more stable air. Another possible factor contributing to Ketsana's weakening was interference from a large disturbance (pre-Melor) located to the southeast. At 0000 UTC on 24 October Typhoon Ketsana was centred 500 nm west- southwest of Iwo Jima and moving northeastward at 4 kts. A 16-nm diameter eye was visible, but the warning issued at 24/0600 UTC indicated that Ketsana was beginning extratropical transition. The MSW had fallen to 85 kts by 24/1800 UTC, and drier air had penetrated into the circulation by this time. The forward speed had doubled, reaching 16 kts at 25/0000 UTC as Ketsana kept up its northeast to north-northeastward heading. At the time of the last JTWC warning at 26/0000 UTC, the MSW had fallen to 70 kts and Ketsana was racing north- eastward at 34 kts over waters east of Japan. The extratropical storm continued northeastward, turning more to the north on the 28th. By 0000 UTC on 29 October the former typhoon was a weakening 35-kt gale located in the Bering Sea. (Editor's Note: The peak 10-min avg MSW assigned by JMA was 85 kts with an attendant minimum CP of 940 hPa. Ketsana's peak MSW estimates from NMCC, PAGASA, and CWBT were 100 kts, 85 kts, and 85 kts, respectively.) C. Casualties and Damage ------------------------ Typhoon Ketsana was a threat to marine interests only and no casualties or damages are known to have resulted from the cyclone. (Report written by Kevin Boyle) SUPER TYPHOON PARMA (TC-21W / TY 0318) 20 October - 2 November ------------------------------------------- Parma: contributed by Macau, is a favorite Macanese food served in Portuguese restaurants in Macau--ham with chicken livers and mushrooms A. Storm Origins ---------------- The long, illustrious career of Typhoon Parma began on 18 October when an area of convection developed about 200 nm east-northeast of Guam. A broad zone of convection south of a weak LLCC was noted, and an upper- air analysis indicated weak vertical shear and equatorward diffluence over the region. The STWO initially referencing the disturbance was issued by JTWC at 18/0300 UTC, and at 0700 UTC another interim STWO was released, locating the system a little further north to a position about 230 nm northeast of Guam and upgrading the development potential to fair. Satellite imagery revealed a very small area of deep convection associated with a well-organized mid-level circulation; maximum surface winds were estimated at 15-20 kts. At 1100 UTC on 19 October a TCFA was issued. Convection was starting to organize over the LLCC, vertical shear was weak, and outflow was fair. The MSW was then estimated at around 20-25 kts. At 0600 UTC on the 20th, JMA classified the system as a 30-kt tropical depression. At 20/1100 UTC JTWC re-issued the TCFA, locating the system about 280 nm south-southeast of Iwo Jima. Shortly afterward, the first JTWC warning on Tropical Depression 21W was issued. The depression was tracking west-northwestward at 6 kts and the initial warning intensity was estimated at 25 kts. The system was being steered by a low to mid-level ridge located to the east, but was forecast to veer toward the northeast after about 12 hours. By 1800 UTC TD-21W was located about 240 nm south-southeast of Iwo Jima and was moving northwestward at 7 kts. Water vapor imagery indicated increasing convection in all quadrants and the MSW was upped to 30 kts. B. Storm History ---------------- The depression was upgraded to tropical storm intensity at 21/0000 UTC by JTWC, NMCC and JMA with the latter assigning the name Parma. The LLCC was on the eastern edge of the deep convection and CI estimates were 35 kts. By 0600 UTC Tropical Storm Parma was moving slowly north- eastward as a ridge to the southeast strengthened. JTWC relocated the center 75 nm east of the 0000 UTC position based upon visible satellite imagery. Parma's center at 0600 UTC was located approximately 250 nm southeast of Iwo Jima. The cyclone continued to steadily intensify as it moved slowly northeastward, and by 0600 UTC on 22 October the center was located about 320 nm east-southeast of Iwo Jima. The storm was exhibiting tightly-curved banding with outflow in all directions. JTWC (and NMCC) upped the winds to 60 kts, but interestingly, JMA upgraded Parma to typhoon status at 0600 UTC. The other two agencies upgraded Parma to a typhoon six hours later. Microwave imagery (85 GHz) from a TRMM pass at 22/1129 UTC revealed a ragged 40-nm diameter eye beginning to form. Late on 22 October Typhoon Parma begin to intensify rapidly. The MSW was bumped to 80 kts at 23/0000 UTC, to 90 kts at 0600 UTC, and to 110 kts at 1200 UTC. At the latter hour the typhoon was centered about 535 nm east-northeast of Iwo Jima. A 23/1031 UTC SSM/I pass indicated the presence of a 35-nm diameter eye, and CI estimates ranged from 90 to 115 kts. The northeastward motion continued, gradually accelerating to 17 kts by 1800 UTC with the storm located approximately 1500 nm west of Midway Island. After a slight weakening at 23/1800 UTC, Parma's intensification trend continued on the 24th. JTWC upped the MSW to 125 kts at 24/0600 UTC, based on CI estimates of 115, 127 and 140 kts. Animated multi-spectral imagery revealed a 30-nm diameter eye with good poleward and equatorward outflow. A 24/1023 UTC SSM/I pass showed the beginning of some dry air entrainment into the western side of the system, but this was not enough to keep Parma from continuing to intensify. The storm reached its peak intensity of 130 kts at 1200 UTC, based on CI estimates of 127 and 140 kts, making Parma the season's fourth super typhoon (per JTWC nomenclature). It is very unusual indeed for a tropical cyclone to attain super typhoon status north of the 30th parallel. Super Typhoon Parma was then located approximately 1265 nm west-northwest of Midway Island. The storm's motion had become increasingly easterly with Parma moving east-northeastward at 22 kts, and by 1800 UTC the storm was racing eastward at 27 kts. A 24/1435 UTC TRMM pass depicted a 35-nm diameter eye, and storm-force winds extended outward over 100 nm to the northeast and southeast and out to 65 nm in the western quadrants. Gales covered an area almost 300 nm in diameter. The minimum CP estimated by JMA was 930 mb. JMA's and NMCC's peak 10-min avg MSW estimates were 95 and 90 kts, respectively. Parma was a rare example of an intense typhoon for which JMA's intensity estimates exceeded those from NMCC. Parma did not remain a super typhoon for long--a 24/2248 UTC SSM/I pass depicted eyewall erosion in the northwest quadrant, so the MSW was decreased to 125 kts at 25/0000 UTC. The storm's motion had by this time become east-southeasterly at 19 kts as it tracked along the northeastern periphery of a large mid-level ridge to the southwest. Typhoon Parma over the next few days would circumnavigate this ridge, describing a huge anticyclonic loop spanning 20 degrees of longitude and almost 10 degrees of latitude. By 25/1200 UTC the typhoon had weakened to 115 kts, and the eye was not apparent in infrared imagery, although bursts of new convection were being noted. Parma was then located approximately 500 nm north of Wake Island and was moving southeastward at 21 kts along the eastern side of the aforementioned steering ridge. The 26th of October saw Typhoon Parma weaken to minimal typhoon status as it moved past the ridge axis and changed to a southwesterly heading. The system ran into some northerly shear, but a 26/0704 UTC SSM/I pass indicated that it was still vertically stacked. The storm was moving south-southeastward at 9 kts at 0600 UTC, but by 1200 UTC the motion had changed to southwesterly at 16 kts, and to west- southwesterly by 1800 UTC. The MSW was dropped to 65 kts at 1800 UTC, although water vapor imagery indicated that outflow was being enhanced by an upper-level trough to the east of the typhoon. Parma at this time was centered approximately 175 nm north-northeast of Wake Island. The steady-state minimal typhoon continued moving westward on the 27th around the southern side of the steering ridge. Satellite CI estimates remained at 65 and 77 kts, but a 27/0847 UTC SSM/I pass indicated that the system had strengthened during the past 12 hours and that a 60-nm diameter microwave eye had formed. This was the beginning of Parma, Round 2. JTWC upped the winds to 75 kts at 1200 UTC with the storm located 265 nm northwest of Wake Island. By 1800 UTC Parma was zipping westward at 20 kts. The rapid westward motion continued through 28 October, becoming west-northwestward by 28/1800 UTC. At 1200 UTC Parma was centered about 720 nm west-northwest of Wake Island, and although CI estimates were still 65 and 77 kts, the cyclone had moved into an area of favorable diffluence aloft and was showing continued signs of further intensification. JTWC upped the MSW to 80 kts at this time, and JMA upgraded Parma to typhoon status once more. Two significant things happened to Typhoon Parma on 29 October: (1) the storm's heading changed abruptly from northwestward to northeastward, and (2) the storm reached intense typhoon status for the second time. The recurvature toward the northeast was well-forecast. A trough approaching from the west weakened the ridge and the typhoon increasingly turned toward the northwest. By 29/1800 UTC the storm's motion had become northeasterly at 9 kts. JTWC upped the MSW to 95 kts at 29/0000 UTC; satellite intensity estimates were 90 and 102 kts, and the system sported a well-defined 15-nm eye. By 1200 UTC Parma was located approximately 590 nm north-northeast of Saipan, and CI estimates ranged from 102 to 127 kts. The typhoon had become better organized with warmer eye temperatures. Typhoon Parma reached a secondary peak intensity of 115 kts at 1800 UTC on 29 October. (JMA's and NMCC's estimated peak 10-min avg MSW values during this phase of Parma's life were 85 and 90 kts, respectively.) This second intensification of Parma into an intense typhoon at a fairly high latitude (26N) was quite unusual, and another very interesting aspect of this phase of the storm's life was the track. From the point of recurvature at 29/1200 UTC until the typhoon had crossed 160E once more around 31/0000 UTC, Parma's track lay almost perfectly on top of its former trajectory of a week earlier. The secondary peak intensity of 115 kts was maintained through 0000 UTC on 30 October. Microwave imagery suggested that Parma had concentric eyewalls, but a 29/2314 UTC SSM/I pass depicted eyewall erosion in the northwest quadrant of the inner eyewall. The storm was beginning to feel the effects of northwesterly shear, and its demise was rather rapid. By 30/1800 UTC Parma winds were down to 85 kts, and the storm was moving rapidly east-northeastward at 26 kts from a position about 825 nm northwest of Wake Island. The typhoon was already beginning to interact with a baroclinic zone and was forecast to be extratropical within 12 hours. Animated visible imagery around 31/0000 UTC indicated that the LLCC was exposed on the southern edge of the deep convection. Parma had crossed the ridge axis and had become decoupled from the mid- level circulation. JTWC decreased the MSW to 70 kts, and the final warning from that agency was issued at 31/0600 UTC. Parma at this time was located approximately 750 nm north of Wake Island, racing east- northeastward at 32 kts. The MSW had fallen to 55 kts and animated water vapor imagery indicated that the system was completely extra- tropical. The remnant extratropical storm continued to race east- northeastward across the North Pacific as it slowly weakened. The final reference to the system in JMA's bulletins at 0000 UTC on 2 November placed a 30-kt LOW about 500 nm to the east-northeast of Midway Island. C. Damage and Casualties ------------------------ No damage or casualties are known to have resulted from Super Typhoon Parma. (Report written by Gary Padgett) TYPHOON MELOR (TC-24W / STS 0319 / VIRING) 30 October - 5 November ----------------------------------------------- Melor: contributed by Malaysia, is the jasmine flower, a pleasant- smelling flower traditionally used to decorate ladies hair Viring: PAGASA name, is a Filipino female nickname A. Storm Origins ---------------- At 0600 UTC on 28 October JTWC issued a STWO for an area of convection located approximately 220 nm north-northwest of Palau. QuikScat data revealed a weak LLCC at this time and the development potential was assessed as poor. This suspect area increased in organisation and convection, prompting an upgrade to fair development potential at 28/1430 UTC. This was followed by the issuance of a TCFA at 30/0330 UTC. The first warning on Tropical Depression 24W was released at 30/0600 UTC, locating the centre of the small system approximately 200 nm east of the Philippines. The second warning, at 30/1200 UTC, upgraded the depression to tropical storm status with JMA simultaneously upgrading and naming the storm Melor. (PAGASA had already named the system Viring by this time.) B. Storm History ---------------- Tropical Storm Melor was moving west-northwestward towards the Philippines at 10 kts at 31/0000 UTC. The MSW at this time was 45 kts, and Melor quickly outgrew its humble, pint-sized beginnings, strengthening to minimum typhoon intensity by 31/1200 UTC. A large 45-nm irregular eye was observed at 31/1112 UTC in SSM/I imagery. At the time of the upgrade to 65 kts, Melor was located 190 nm east- northeast of Manila, Philippines, and still moving on a west- northwesterly path at 13 kts. This west-northwesterly heading changed to northwesterly at 1800 UTC as a mid-level ridge began to build over southeastern China. There was room for more intensification on the 1st of November and the MSW strengthened to a peak of 75 kts at 01/0600 UTC. By this time Typhoon Melor had turned toward the northwest and was crossing Luzon with typhoon-force winds, but signs of weakening were evident with the effects of landfall weakening the associated deep convection. Also, clouds could be seen in satellite images streaming away from Melor's northern sectors under the effects of shearing. The intensity fell to 65 kts at 1800 UTC, and then to below typhoon intensity at 02/0000 UTC. At 0000 UTC on 2 November the downgraded Tropical Storm Melor was located approximately 370 nm north of Manila, tracking north- northwestward at 7 kts. Multi-spectral and infrared satellite imagery revealed that the majority of the deep convection was concentrated in an area north of the partially-exposed LLCC. Melor managed to maintain a MSW of 60-kt through the 2nd as it turned northward, its ragged eye feature clipping the southern coastline of Taiwan at 02/1200 UTC. Following dry air entrainment, Melor's strength declined further with the MSW dropping to 55 kts at 02/1800 UTC. Infrared satellite imagery at 0000 UTC on 3 November showed an untidy, messy circulation almost devoid of deep convection. Tropical Storm Melor, now approximately 125 nm south of Taipei, Taiwan, was moving north-northeastward at 8 kts with a MSW of 45 kt. This intensity was maintained throughout the 3rd, and despite Melor's forming a weak circular CDO feature, as seen in 03/1200 UTC infrared satellite imagery, the tropical cyclone was dissipating as a significant tropical cyclone over water. At 0000 UTC on the 4th Melor had weakened to a weak swirl of low clouds barely at tropical storm intensity. Animated multi-spectral imagery indicated that the mid-level circulation had separated from the completely-exposed LLCC. JTWC declared the system extratropical and issued the final warning, locating the centre approximately 245 nm southwest of Okinawa. The remnant circulation could be seen being dragged off east-northeastward by a frontal system. The LOW passed well south of Japan during the 4th, and by 05/0000 UTC was barely discernible in satellite images. (Editor's Note: It should be pointed out that JTWC was the only agency to classify Melor as a typhoon. A peak 10-min avg MSW of 60 kts was reported by all the Asian TCWCs. The lowest CP estimated by JMA was 975 hPa. JTWC's peak 1-min avg MSW of 75 kts occurred at 0600 UTC on 1 November after the center of Melor had already made landfall in Luzon, so 75 kts could be a little questionable.) C. Meteorological Observations ------------------------------ The following meteorological observations from Taiwan were compiled and sent by Huang Chunliang. A special thanks to Chunliang for sending the information. Station City/County Period (UTC) Rainfall (mm) -------------------------------------------------------------------- Kenting Pingtung County 01/1600 - 02/2100 554 Checheng Pingtung County 01/1600 - 02/1500 400 Chih Pen Taitung County 01/1600 - 02/2100 191 Lanyu Taitung County 01/1600 - 03/0000 142 Dawu Taitung County 01/1600 - 02/2100 182 Melor broke a record in the history of Station Hengchun (WMO 46759/ 59559), the new one for daily rainfall recorded in November being 430.5 mm (01/1600 - 02/1600 UTC, November, 2003). Station Lanyu (WMO 46762/59567, Altitude 325 m) experienced gusts of typhoon force during the passage of Melor. Station: Hateruma, Okinawa (JMA 94116) -------------------------------------- Latitude: 24.06 N Longitude: 123.77 E Altitude: 38 m Rainfall Period (UTC) - November, 2003 ---------- ------------------------------- 34 mm 03/1200 - 03/1300 92 mm 03/1300 - 03/1400 34 mm 03/1400 - 03/1500 Melor broke two records in the history of the station, the new ones for hourly and daily rainfall recorded in November being 92 mm (03/1300 - 03/1400 UTC) and 181 mm (02/1500 - 03/1500 UTC), respectively. D. Damage and Casualties ------------------------ No reports of damage of casualties resulting from Typhoon Melor have been received. The storm did strike Luzon as either a strong tropical storm or minimal typhoon, but not even the ReliefWeb's internet site contains any information about Melor's effects in the Philippines. Therefore, it seems quite likely that there were few if any casualties and that damage was relatively light. (Report written by Kevin Boyle with contributions by Huang Chunliang) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for October: 1 tropical depression ** 1 tropical storm ++ ** - treated as a tropical depression by IMD only ++ - visitor from Gulf of Thailand--treated as a tropical depression by IMD and Thai Meteorological Department North Indian Ocean Tropical Activity for October ------------------------------------------------ Two systems traversed the waters of the Bay of Bengal during October. The first of these was treated as a depression by the India Meteor- ological Department (IMD) only. The second was Tropical Depression 23W, a visitor from the Gulf of Thailand, which reached minimal tropical storm intensity (per JTWC's analysis) before moving inland in India. Huang Chunliang compiled and sent some rainfall reports from both systems, as well as some press reports describing damage in Thailand due to flooding associated with the early stages of TD-23W. A special thanks to Chun- liang for sending the information. TROPICAL DEPRESSION 6 - 8 October --------------------------------------- This system was classified as a depression by the Meteorological Department of India (IMD) only. IMD upgraded the LOW to a depression at 0300 UTC on 6 October when located approximately 100 nm southeast of Visakhapatnam. JTWC issued no warnings nor TCFA, but did assign a fair development potential at one point. The system moved generally north-northwestward, and according to the IMD warnings, crossed the north Andhra coast near Kalingapatnam around 06/2130 UTC. The system had weakened into a low-pressure area by 09/0300 UTC. No peak winds were specified in IMD's bulletins, but it was classified as only a depression (25 kts) as opposed to a deep depression (30 kts). Following are rainfall reports from various stations in India: State/Union Territory Station Period (UTC) Rain (cm) ----------------------------------------------------------------------- Orissa Berhampore 05/0300 - 06/0300 15 Orissa Puri 05/0300 - 06/0300 12 Orissa Gopalpur 05/0300 - 06/0300 16 Orissa Gopalpur 06/0300 - 07/0300 10 Orissa Chandbali 06/0300 - 07/0300 27 Orissa Cuttack 06/0300 - 07/0300 11 Orissa Paradeep 06/0300 - 07/0300 10 West Bengal Digha 06/0300 - 07/0300 23 Andhra Pradesh Parvathipuram 06/0300 - 07/0300 13 Andhra Pradesh Vishakapatnam 06/0300 - 07/0300 12.3 West Bengal Calcutta (ALP) 07/0300 - 08/0300 10.91 West Bengal Calcutta (DD) 07/0300 - 08/0300 16.23 West Bengal Canningtown 07/0300 - 08/0300 23 West Bengal Dum-Dum 07/0300 - 08/0300 16 West Bengal Mohanpur 07/0300 - 08/0300 14 West Bengal Midnapore 07/0300 - 08/0300 13 West Bengal Alipore 07/0300 - 08/0300 11 Orissa Akhuapada 07/0300 - 08/0300 12 Orissa Anandapur 07/0300 - 08/0300 11 Orissa Baripada 07/0300 - 08/0300 11 Orissa Chandbali 07/0300 - 08/0300 11 Orissa Jeypore 07/0300 - 08/0300 11 West Bengal Calcutta (ALP) 07/0300 - 08/0300 16 West Bengal Digha 07/0300 - 08/0300 14 Chhattisgarh Jagdalpur 07/0300 - 08/0300 14 Jharkhand Tenughat 08/0300 - 09/0300 22 Jharkhand Konar 08/0300 - 09/0300 16 Jharkhand Ramgarh 08/0300 - 09/0300 15 Jharkhand Hindigir 08/0300 - 09/0300 11 Jharkhand Maharo 08/0300 - 09/0300 11 Jharkhand Ranchi 08/0300 - 09/0300 10 Jharkhand Barkisurya 08/0300 - 09/0300 10 Bihar Tantloi 08/0300 - 09/0300 13 Bihar Messanjore 08/0300 - 09/0300 13 West Bengal Malda 09/0300 - 10/0300 15 West Bengal Cooch-behar 09/0300 - 10/0300 13 West Bengal Alipurduar 09/0300 - 10/0300 11 West Bengal Jalpaiguri 09/0300 - 10/0300 11 West Bengal Domohani 09/0300 - 10/0300 10 Bihar Bhagalpur 09/0300 - 10/0300 11 Assam Tezpur 10/0300 - 11/0300 14 Assam Guwahati 10/0300 - 11/0300 11 West Bengal Jalpaiguri 10/0300 - 11/0300 11 Meghalaya Shillong 10/0300 - 11/0300 19 Note: IMD only classified the system as a depression from 6-8 October, 2003. Significant storm rains during both the formative and fading stages, however, are also listed above. (Report written by Gary Padgett based primarily upon information sent by Huang Chunliang) TROPICAL STORM (TC-23W) 22 - 28 October ----------------------------------- A. Storm History ---------------- A STWO issued by JTWC at 1700 UTC on 21 October noted that an area of convection had developed in the Gulf of Thailand about 250 nm south of Bangkok. Microwave imagery depicted a well-defined LLCC, and a 200-mb analysis indicated weak to moderate vertical shear with good diffluence aloft. The initial development potential was assessed as fair. By 2300 UTC the convective organization had continued to improve so the development potential was upgraded to good. At 0600 UTC on 22 October the Thai Meteorological Department (TMD) initiated tropical depression bulletins on the system. At 23/0600 UTC the system was centered approximately 200 nm south of Bangkok or about 130 nm east of the Malay Peninsula. Convection was still cycling over a partially- exposed LLCC so warnings were not initiated. However, a QuikScat pass shortly afterward revealed an unflagged 25-kt wind vector, so the first JTWC warning on Tropical Depression 23W was issued at 0900 UTC. The depression was quasi-stationary at the time, but after about 24 hours was forecast to begin tracking westward along the southern periphery of a low to mid-level ridge to the north. The depression remained quasi-stationary for most of the 23rd, but by 1800 UTC was moving north-northwestward at 5 kts. The system was located in an environment of weak steering south of a low to mid-level ridge. Satellite imagery revealed a compact LLCC with persistent but disorganized deep convection. At 0600 UTC on 24 October the center of TD-23W was located about 130 nm south of Bangkok, still moving slowly northwestward. The system had not changed appreciably in organization since the previous day. As the day wore on the center of TD-23W approached the coast of Thailand and began to weaken. The center made landfall near Hua Hin at approximately 24/1500 UTC with winds estimated at 25 kts, gusting to 35 kts. At 1800 UTC the depression's center was located approximately 30 nm northwest of Hua Hin, moving northwestward at 8 kts. By 0600 UTC on 25 October TD-23W had moved into the Bay of Bengal and was located approximately 185 nm west-southwest of Bangkok. This position represented a major westward relocation of the center. Animated multi-spectral imagery and data from a recent QuikScat pass revealed that the center was located much farther west from the previous warning position. At 1800 UTC the system was tracking westward at 13 kts as the ridge to the north built. However, convection appeared to have weakened during the previous 12 hours. By 1800 UTC on 26 October the depression was located about 90 nm west of the Andaman Islands, tracking westward at 10 kts. Satellite CI estimates were 25 and 30 kts, but animated enhanced infrared imagery indicated increasing deep convection over the LLCC, so the MSW was upped to 30 kts. The system's organization continued to improve and some CI estimates had reached 35 kts by 27/0600 UTC. The LLCC was partially- exposed, but deep convection was continuing to build near the center. JTWC upped the MSW to 35 kts at 0600 UTC with the center located about 400 nm south of Calcutta. The system was then moving west-northwestward at 14 kts. By 1800 the storm was moving northwestward at an even faster speed of 19 kts. Intensity estimates were 30 and 35 kts, so the MSW remained at 35 kts. Since TC-23W was forecast to encounter a slightly more favorable upper-level environment, some slight strengthening was forecast before landfall in eastern India. By 0600 UTC on 28 October TC-23W had made landfall and was weakening. The final JTWC warning at 28/0600 UTC placed the center about 50 nm northeast of Visakhapatnam, India. B. Meteorological Observations ------------------------------ (1) Thailand ------------ According to the TMD warnings, Tropical Depression 23W had made landfall over Prachuap Khiri Khan Province by 24/0900 UTC on 24 October, 2003. Following are some rainfall reports sent by Huang Chunliang. Province/ Station Period Rain Metropolis (UTC) (mm) ------------------------------------------------------------------------ Trang Sikao 21/0000 - 22/0000 127.7 Prachuap Khiri Khan Hua Hin 24/0000 - 25/0000 197.0 Prachuap Khiri Khan Nong Plub (Agromet)* 23/1200 - 24/1200 145 Prachuap Khiri Khan Nong Plub (Agromet)* 24/0000 - 25/0000 187 Bangkok Lam Hin Police Station 24/0000 - 25/0000 69.0 Note (*): Agromet = Agrometeorological Station (2) India --------- According to the IMD warnings, TC-23W crossed coastal Andhra Pradesh between Visakhapatnam and Kalingaptnam as a deep depression (i.e., 30 kts) around 28/0900 UTC. Station Dummagudem, in the state of Andhra Pradesh, recorded 12 cm of rainfall in the 24 hours between 28/0300 and 29/0300 UTC. C. Damage and Casualties ------------------------ The following information was condensed from press reports sent to the author by Huang Chunliang. Thousands were hit by monsoon flooding along Thailand's south-central coast, bringing road and rail transport to a virtual halt and forcing the evacuation of more than 700 people. Nearly 10,000 people were affected by heavy rains (200-300 mm) that lashed Phetchaburi Province, adjacent Prachuap Khiri Khan to the south, and Ratchaburi. More than 8700 people were severely affected in Phetchaburi alone, where 746 people were evacuated from their homes. The State Railway of Thailand suspended service between Bangkok and points south of Petchaburi, stranding thousands of would-be passengers in the capital, while flash-flooding rendered several main roadways impassable. The series of severe tropical storms also wrought havoc at sea, with at least 20 fishermen still missing (at the time of the report) from two trawlers that capsized in the Gulf of Thailand. The trawlers capsized between 40 and 60 nautical miles (74 and 111 kilometres) east of the popular destination island of Ko Samui during a fierce tropical storm. Police and rescuers from a nearby gas drilling platform saved 15 men who were on the ill-fated boats. The Thai navy helped rescue some 300 tourists from the southern resort island of Koh Tao, near Ko Samui, after high seas left them stranded without ferry or flight service. (Report written by Gary Padgett with significant contributions by Huang Chunliang) ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for October: No tropical cyclones Southwest Indian Ocean Tropical Activity for October ---------------------------------------------------- No tropical cyclones formed in the Southwest Indian Ocean during the month of October. A tropical depression formed in late September and was named Tropical Storm Abaimba on 1 October. This system meandered slowly for a few days deep in the tropics several hundred miles west of Diego Garcia. The report on Abaimba can be found in the September tropical cyclone summary. ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for October: No tropical cyclones ************************************************************************* NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E Activity for October: No tropical cyclones ************************************************************************* SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E Activity for October: 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 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, and Chris Landsea): 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 2002 (2001-2002 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 2002 Atlantic and Eastern North Pacific tropical cyclones; also, storm reports for all the 2002 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 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 ************************************************************************* ************************************************************************* >> Published: 03.09.04 Typhoon2000.com / Typhoon2000.ph