Tropical
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Monthly Global Tropical Cyclone Summary November 2005 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY NOVEMBER, 2005 (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 --> Three more Atlantic tropical storms up 2005 total to 26 named storms --> Western North Pacific and North Indian Ocean see some activity --> Intense tropical cyclone roams South Indian Ocean waters ************************************************************************* ACTIVITY BY BASINS ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico Activity for November: 3 tropical storms ** ** - one of these reached hurricane intensity in early December 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 --------------------------------------- Following the dissipation of Hurricane Beta over the mountains of Nicaragua during the final days of October, the Atlantic basin enjoyed a two-week respite from the almost non-stop tropical cyclone activity it had seen since July. However, things started bubbling again in the Caribbean and subtropics during the middle and latter parts of the month. After traversing the length of the Caribbean Sea as a tropical depression, Tropical Storm Gamma formed just off the coast of Honduras around mid-month and lingered in the same area for a few days until it dissipated. The east-central Atlantic subtropics then became a hotspot, producing two tropical cyclones within a few days of each other during the final days of November, plus another to come in late December. Tropical Storm Delta formed on the 23rd and followed an unusual southerly track before taking off to the east-northeast on the 26th. Delta became a strong tropical storm, and there is a possibility that it briefly reached hurricane intensity on 27 November, but the data were deemed not conclusive enough to justify a posthumous upgrade to hurricane status. Shortly after becoming an extratropical LOW, Delta swept by the Canary Islands on its way to a Moroccan landfall, causing extremely strong winds in the islands which led to widespread damage. Finally, another non-tropical LOW on the heels of Delta acquired tropical characteristics on 29 November and was named Tropical Storm Epsilon. Epsilon became a hurricane on 2 December and remained so for 5 days--the longest-lived December hurricane on record. Most of the official TPC/NHC reports for 2005 Atlantic tropical cyclones are now available online at the following link: http://www.nhc.noaa.gov/2005atlan.shtml> Since the reports for all three November storms are now available, I have written only fairly brief reports on these systems, based largely on the official storm reports. Climatologically speaking, November, 2005, was one of the more active months of November on record in terms of named storms, equaling the record of three established in 2001. (Technically, Hurricane Michelle was upgraded to a tropical storm shortly before 0000 UTC on 1 November, but anyone using the Best Track file would see the first 35-kt MSW at 01/0000 UTC and so would count it as a November tropical storm.) However, all three of the 2001 storms became hurricanes, while none of the 2005 cyclones did, except for Epsilon in December, so it counts as a December hurricane. Based on the period 1950-2004, the NTC generated by Gamma, Delta, and the first 1.5 days of Epsilon amounts to 7.7%, above the November average NTC of 4.0% but far less than the 34.8% in November, 2001, or the 22.9% in November, 1999. Other fairly active Novembers include: Year NS H IH NTC ---------------------------------------- 1956 1 1 1 18.5% 1969 2 2 0 13.3% 1980 2 2 0 13.9% 1985 1 1 1 21.2% 1994 2 2 0 17.2% 1999 1 1 1 22.9% 2001 3 3 1 34.8% TROPICAL STORM GAMMA (TC-27) 14 - 21 November ---------------------------------------- The official TPC/NHC storm report on Tropical Storm Gamma, written by Stacy Stewart, is now available on NHC's website. Tropical Storm Gamma, the 24th named tropical storm of the 2005 Atlantic season, formed from an unusually late-season vigorous tropical wave which moved off the coast of western Africa on 3 November. The wave was accompanied by an unusually large amount of deep convection and produced wind gusts to near tropical storm force with locally heavy rainfall as it moved across the southern Windward Islands on 13 November. Unfavorable vertical shear relaxed some once the system had entered the southeastern Caribbean Sea, and it had become organized enough such that advisories were initiated on Tropical Depression 27 at 0300 UTC on the 14th. The depression was centered about 100 nm west of St. Lucia or about 90 nm west of St. Vincent, moving west-northwestward at 9 kts. The depression was forecast to strengthen into a tropical storm, and according to the official report, it did reach minimal tropical storm intensity for about 12 hours at 0600 UTC on 15 November while located well to the south of Puerto Rico. However, westerly shear increased and the system had weakened to a depression by 15/1800 UTC. The NHC storm report seems to imply that the depression was named Tropical Storm Gamma at this time, but the system was not treated as a tropical storm at this stage operationally. The depression continued to weaken and was downgraded to a tropical wave and advisories terminated at 1500 UTC on 16 November with the center of the remnants of TD-27 located about 265 nm southeast of Kingston, Jamaica. A deep-layer ridge to the north forced the remnants of TD-27 to accelerate westward at 20-22 kts across the central Caribbean Sea before slowing down near eastern Honduras on 17 November. During the same time interval a broad but well-defined low-pressure system had formed over Panama and moved northwestward over the south- western Caribbean and into northeastern Nicaragua on 16 November. This system either merged with or underwent a complex interaction with the remnants of TD-27 over the mountainous terrain of Honduras early on the 18th. A midday reconnaissance flight found that a broad circulation had formed just north of the Honduran coast with a peak FLW of 49 kts at 450 metres along with two spots of 45 kts north of the center. Based on these observations, advisories were re-initiated on the system as Tropical Storm Gamma at 18/2100 UTC, placing the center about 35 nm north of Limon, Honduras. Steering currents were very weak and over the next three days Tropical Storm Gamma moved very slowly and erratically along and just to the north of the eastern Honduran coastline. The peak MSW assigned operationally to Gamma was 40 kts, but the Best Track file shows that in post-storm analysis the intensity was upped slightly to 45 kts at 19/1200 UTC when it was located just east of Roatan Island. Later on the 19th Gamma began a slow drift to the east, and the next day began moving more quickly to the southeast. Shear began to increase from the northwest and displaced most of the convection well to the southeast of the LLCC. Gamma began to weaken and was downgraded to a tropical depression at 20/1200 UTC. By early on 21 November Gamma had degenerated into a non-convective remnant LOW and had dissipated by 0600 UTC on 22 November just east of the Honduras-Nicaragua border. A graphic depicting the operational track of Tropical Storm Gamma may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/atlantic/BT-IMAGES/2005-27L-GAMMA.gif> Reports from the Government of Honduras and the news media indicate that 37 fatalities occurred due to Tropical Storm Gamma: 34 in Honduras and 3 in Belize. The deaths were the result of flash floods and mud- slides caused by the heavy rainfall. An additional 13 persons were listed as missing in Honduras. More than 100,000 residents of Honduras were adversely affected by Gamma as their homes were damaged and the electrical service interrupted. There was also a shortage of food and water. The floods destroyed 5200 acres of banana crops, and reports from private companies indicate that banana crop losses were around $13-$18 million U. S. dollars. (Report written by Gary Padgett, based on the official TPC/NHC storm report by Stacy Stewart) TROPICAL STORM DELTA (TC-28) 21 - 30 November ---------------------------------------- The official TPC/NHC storm report on Tropical Storm Delta, written by Jack Beven, is now available on NHC's website. Delta, the 25th named storm of the 2005 Atlantic hurricane season, was the first in a series of three late-season storms of non-tropical origin to form in the east-central subtropical Atlantic. Delta was unique in the annals of Atlantic tropical history in that it caused, in its extra- tropical stage, extremely strong winds well above hurricane force in the Canary Islands which led to widespread damage. Also, the post-Delta extratropical cyclone is the only case known to the author in which a former tropical cyclone struck the African continent with gale-force winds or higher. Delta's origins lay with a broad low-pressure area which formed on 19 November about 1200 nm southwest of the Azores. Initial motion was east-northeastward through the 20th while it was located in the vicinity of a cold front trailing from another LOW to the north. The pre-Delta system then turned northeastward on 21 November and began developing some central convection. On the morning of the 22nd QuikScat data indicated the formation of an inner wind maximum while AMSU data revealed that an upper-level warm core had formed--both characteristics of subtropical and tropical cyclones. The LOW subsequently became more isolated from frontal cloud bands and began a south-southwestward motion late that day. The convection consolidated and advisories were initiated on Tropical Storm Delta at 2100 UTC on 23 November. The center was estimated to be located about 1000 nm southwest of the Azores with a MSW of 50 kts. QuikScat data showed a few uncontaminated 50-kt wind vectors, and Buoy 62556, located about 50 nm east of the center, reported a pressure of 986.5 mb at 23/1600 UTC. (Note: In post-storm analysis it was determined that the system had become classifiable as a subtropical storm by 22/1800 UTC, and the Best Track reflects this. However, it was not classified as a subtropical storm operationally.) Over the next couple of days Tropical Storm Delta moved generally southward, initially southeastward followed by a turn to the southwest. Delta's intensity increased slowly, reaching a first peak of 60 kts by 1200 UTC on 24 November. The southerly motion slowed and Delta turned eastward and then east-northeastward on the 26th. During this period vertical shear increased and the cyclone had weakened into a minimal 35-kt tropical storm by 1200 UTC on the 26th. Delta began to accelerate to the east-northeast on the 27th in response to an intensifying deep-layer trough over western Europe. The storm surprised forecasters as it underwent a sharp re-intensification on the 27th. In fact, during the evening of 26 November some very deep convection with tops colder than -70 C developed to the east-northeast of the mostly- exposed LLCC. This persisted throughout the night, and the discussion bulletin at 27/0900 UTC noted that the convection was about as strong as it had been during the lifetime of the cyclone. But given the uncertainty in just where the center was located in relation to the deep convection, the MSW remained at 35 kts as Delta was expected to soon weaken and become extratropical. During the morning Delta developed an eye-like feature in visible and infrared imagery, so the MSW was bumped up to 45 kts at 1500 UTC. Low- level cloud lines suggested that the surface center was located a little to the southwest of the mid-level eye. The MSW was increased to a second peak of 60 kts at 2100 UTC based on a report of 60-kt winds and a pressure of 991 mb at 1800 UTC from ship VQIB9, which was located about 50 nm north of the center and had a history of reliable observations. The satellite appearance, however, had already begun to deteriorate by this time so no additional strengthening was considered likely. On the 28th Delta turned more to the east as it moved into a surface baroclinic zone associated with the European trough. The storm began to lose its tropical characteristics due to increasing vertical shear and cold air entrainment and was declared extratropical at 28/1500 UTC. The final TPC/NHC advisory placed Delta's center about 150 nm northwest of La Palma in the Canary Islands, racing eastward at 26 kts. The remnants of Delta continued eastward, passing about 90 nm north of the Canaries later that day with winds still estimated at 60 kts. The storm moved into Morocco early on 29 November and accelerated rapidly east-northeastward while weakening. It had dissipated over northwestern Algeria by late on the 29th. The possibility exists that Delta did reach hurricane intensity for a brief period on 27 November, based on the satellite signature in visible, infrared and microwave imagery and the 60-kt ship report in what would normally be the weaker side of a cyclone moving rapidly eastward. However, the data were not considered compelling enough to justify an after-the-fact upgrade to hurricane status. A graphic depicting the operational track of Tropical Storm Delta may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/atlantic/BT-IMAGES/2005-28L-DELTA.gif> Some very strong winds were reported in the Canary Islands from the extratropical remnants of Delta. A station on Tenerife reported sustained winds of 63 kts, gusting to 79 kts while a station on La Palma measured a peak gust of 82 kts. The Izana Observatory, located at an altitude of 2367 metres reported sustained winds of 98 kts with a peak gust of 134 kts. No deaths or damages were associated with Delta during its time spent as a tropical cyclone, but as an extratropical LOW it was responsible for 7 deaths in and near the Canary Islands, including 6 African migrants who drowned when their boat capsized. Also, 12 additional people from the boat were reported missing. Power outages were common throughout the Canaries, while roads were blocked by trees and mudslides. Several ports and airports were temporarily closed by the storm, and the strong winds broke a huge rock and natural monument near Agaete, known as the "Finger of God." (Report written by Gary Padgett, based on the official TPC/NHC storm report by Jack Beven) HURRICANE EPSILON (TC-29) 28 November - 9 December -------------------------------------------- The official TPC/NHC storm report on Hurricane Epsilon, written by James Franklin, is now available on NHC's website. Epsilon was the 26th named tropical cyclone of the 2005 Atlantic hurricane season and became the 15th hurricane of the year. The cyclone formed from a non-tropical area of low pressure in the central Atlantic on 29 November about 735 nm east of Bermuda. Coming on the heels of Tropical Storm Delta, Epsilon was the second tropical cyclone to form in the same area within a week. The parent surface gale center had formed on 27 November beneath a non-tropical upper-level LOW, and the transition to a tropical cyclone apparently occurred rather quickly. The official report notes that on 28 November the system did exhibit some of the features of a classic subtropical cyclone, and that a case could be made for classifying it as subtropical late on the 28th. However, since the LOW did not have much organized non-frontal convection prior to 0600 UTC on 29 November, the decision was made not to classify the pre-Epsilon system as a subtropical storm. After being named as a tropical storm, Epsilon moved westward, then dropped to the south and eventually to the northeast, completing a loop. On 2 December, while heading northeastward over 1000 nm west of the Azores, Epsilon was upgraded to hurricane status. This was in spite of moving over slightly cooler SSTs since the previous day. A solid convective band surrounded a well-defined 25-nm diameter eye, and the upper-level outflow pattern had continued to improve. The hurricane, however, was forecast to weaken back into a tropical storm in less than 24 hours. Almost every 6-hourly forecast over the next several days expected Epsilon to remain a hurricane for no more than 24 hours--yet the tenacious storm held on to hurricane intensity for over 5 days. Epsilon generated 5.5 hurricane days in the month of December, doubling the previous high of 2.75 hurricane days set by Hurricane Lili in 1984. (Note: In post-analysis, Epsilon's tenure as a hurricane was reduced by 6 hours at each end, so that based on the Best Track, Epsilon was a hurricane for 5 days.) On 3 December Epsilon's track turned eastward--a track which it was to follow for the next 3 days. This easterly track kept the storm to the south of a belt of strong westerlies. Anticyclonic outflow developed in the northern semicircle and Epsilon took on an annular appearance with a large 30-35 nm diameter eye. The estimated peak intensity of 75 kts occurred early on 5 December. Later on the 5th, the frontal zone associated with a deep-layer trough passed just north of Epsilon with high pressure building behind the trough. This forced the hurricane to embark on a southerly and later southwesterly course. Vertical wind shear remained fairly weak and Epsilon continued to hold on to minimal hurricane intensity for another 2 days. However, as Epsilon continued to move to the southwest, strong upper-level north- westerly flow began to affect the cyclone and it began to weaken. Operationally, Epsilon was downgraded to a tropical storm at 0300 UTC on 8 December while located about 865 nm southwest of the Azores. After this, weakening was rapid and Epsilon was downgraded to a tropical depression on the final NHC advisory at 08/1500 UTC, still moving southwestward. A graphic depicting the operational track of Hurricane Epsilon may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/atlantic/BT-IMAGES/2005-29L-EPSILON.gif> (Report written by Gary Padgett, based upon the official TPC/NHC report by James Franklin) ************************************************************************* 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: 1 tropical depression ** 1 tropical storm 2 typhoons ++ ** - system was classified as a tropical depression by the Central Weather Bureau of Taiwan only ++ - one of these formed in October and was covered in the October summary Sources of Information ---------------------- Most of the information presented below is based upon tropical cyclone warnings and significant tropical weather outlooks issued by the Joint Typhoon Warning Center of the U. S. Air Force and Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion tropical cyclone tracks file, I normally annotate track coordinates from some of the various Asian warning centers when their center positions differ from JTWC's by usually 40-50 nm or more. All references to sustained winds imply a 1-minute averaging period unless otherwise noted. Michael V. Padua of Naga City in the Philippines, owner of the Typhoon 2000 website, normally sends me cyclone tracks based upon warnings issued by the Japanese Meteorological Agency (JMA) and the Philippines' Atmospheric, Geophysical & Astronomical Services Administration (PAGASA). A very special thanks to Michael for the assistance he so reliably provides. 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 ------------------------------------------------ November tropical cyclone activity was about normal during 2005. As the month opened Typhoon Kai-tak was losing steam in the South China Sea and continued to weaken until its landfall in Vietnam on the 2nd. The report on Kai-tak was included in the October summary. Two named storms formed in November--Tropical Storm Tembin and Typhoon Bolaven. The fairly weak Tembin, known in the Philippines at Ondoy, began forming well to the east of Palau on the 6th, and generally followed a west- northwesterly track until it made landfall in central Luzon on the 10th. The storm weakened while crossing the island and dissipated in the South China Sea on the 12th. Typhoon Bolaven (its PAGASA-assigned name being Pepeng) formed east of Mindanao around mid-month, trekked northward, then slowed and moved very erratically for a couple of days as it intensified to typhoon status. Finally, the cyclone took off on a west-northwesterly track but had weakened into a minimal tropical storm before making landfall in extreme northeastern Luzon on the 20th. Another tropical LOW was classified as a weak tropical depression by the Central Weather Bureau of Taiwan (CWB) but apparently not by any other agency. The primary significance of this system was that it underwent a binary action with Bolaven and was likely a contributing factor to the typhoon's very erratic track on the 15th-17th. Huang Chunliang sent me a tabular track of this depression, so because of its influence on Typhoon Bolaven, I have included the CWB track in the report on Bolaven. TROPICAL STORM TEMBIN (TC-23W / TS 0522 / ONDOY) 6 - 12 November ---------------------------------------------- Tembin: contributed by Japan, means 'balance' (weighing device); also is the name of the constellation Libra (the scales) A. Introduction and Storm Origins ---------------------------------- Tropical Storm Tembin developed in the monsoon trough on 7 November. Moving rather quickly west-northwestwards, it reached a maximum intensity of 45 kts before making landfall on the northern Philippine island of Luzon late on 10 November. It dissipated near Taiwan on 12 November. At 0600 UTC 4 November an area of convection persisted approximately 330 nm east-southeast of Palau. Animated multi-spectral satellite imagery showed a consolidating LLCC with deep convection on the southwestern periphery. An upper-level analysis indicated that the disturbance was located in an area of low vertical shear, and a good outflow channel was evident to the east. The system slowly became better organized over the following two days, and a TCFA was issued at 06/1430 UTC. The first warning followed at 07/0600 UTC, placing the centre of the newly-formed Tropical Depression 23W approximately 75 nm north-northwest of Yap. B. Synoptic History ------------------- Moving northwestward at 10 kts, Tropical Depression 23W was upgraded to a tropical storm at 1800 UTC 7 November when located approximately 220 nm north-northwest of Yap. Influenced by a low to mid-level steering ridge located to the northeast, Tropical Storm 23W turned onto a west-northwesterly track and became disorganized on 8 November as it struggled to establish a favourable outflow pattern, virtually losing its supporting deep convection and exposing the LLCC. As a result, it was downgraded to a tropical depression at 08/1200 UTC shortly after entering PAGASA's AOR. That agency assigned the named Ondoy for local use. On 9 November the environment became more conducive for strengthening, and the tropical cyclone was re-upgraded to a 35-kt tropical storm at 0600 UTC 9 October. Tropical Storm 23W reached its peak intensity of 45 kts at 09/1200 UTC while located approximately 405 nm east of Manila, Philippines. This was maintained for the following 24 hours, the system continuing on a rather brisk west- northwestward heading south of a intensifying low to mid-level ridge. JMA raised their MSW estimate to 35-kts and assigned the name Tembin at 10/0000 UTC. Tropical Storm Tembin/Ondoy made landfall on Luzon at 10/1200 UTC at a point approximately 75 nm north-northeast of Manila with the MSW estimated at 45 kts. Once over land, Tembin deteriorated markedly and was downgraded to a tropical depression at 11/0600 UTC. The final warning was issued at 11/1800 UTC after the deep convection had mostly dissipated and the LLCC had become barely discernible. The final position was approximately 235 nm southeast of Hong Kong, China. JMA had released their final statement at 11/0600 UTC. The remnants of Tembin moved northwest and dissipated near Taiwan on 12 November. NMCC and PAGASA estimated a peak intensity of 45 kts (10-min avg). JMA, HKO, CWB of Taiwan and TMD estimated a peak value of 35 kts. The lowest CP estimated by JMA was 1000 mb. A graphic depicting the track of Tropical Storm Tembin/Ondoy may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/w_pacific/BT-IMAGES/2005-23W-TEMBIN.gif> C. Damage and Casualties ------------------------ There were no reports of damage or casualties in the Philippines associated with Tropical Storm Tembin/Ondoy. (Report written by Kevin Boyle) TYPHOON BOLAVEN (TC-24W / STS 0523 / PEPENG) 13 - 20 November ------------------------------------------------ Bolaven: contributed by Laos, is the name of a plateau in southern Laos A. Introduction and Storm Origins ---------------------------------- As Tropical Storm Tembin was dissipating southeast of Taiwan, Typhoon Bolaven began developing east of the Philippines. This system consistently had to face unfavourable wind shear, taking several days to reach typhoon strength and its peak intensity of 75 kts on 17 November. It made landfall over northeastern Luzon, Philippines, as a weakening tropical storm on 20 November. On 12 November an area of convection persisted approximately 150 nm west-southwest of Palau. Remarks in JTWC's TCFA issued at 2200 UTC 12 November include: "A 12/1617 UTC AMSR/E pass and animated enhanced infrared satellite imagery reveals a well-defined and tightening LLCC with deep convection increasing in close proximity to it. An upper- level analysis indicates the area is under low vertical wind shear and outflow is gradually becoming more favourable for development with good diffluence to the west and north." The first warning on Tropical Depression 24W was released at 13/1200 UTC, placing the centre approximately 290 nm west of Palau. Intensifying, TD-24W was upgraded to a 35-kt tropical storm at 14/0600 UTC. The system had been named Pepeng six hours earlier when PAGASA classified it as a tropical depression. B. Synoptic History ------------------- Tropical Storm 24W moved erratically northwards over the next two days as a weakness developed in the mid-level steering ridge induced by a passing mid-latitude trough. The tropical cyclone intensified slowly under moderate to high vertical wind shear, and as a result, the deep convection became displaced west of the LLCC on 15 November. The system was named Bolaven at 16/0600 UTC when JMA raised their 10-min avg MSW to 35 kts. On 16-17 November, Tropical Storm Bolaven drifted aimlessly to the east of the Philippines as it became lodged between weak steering current regimes. Despite exhibiting a large and very symmetric CDO, microwave satellite images at 16/1200 UTC revealed that the deep convection was still located west of the LLCC. However, after the shear lessened and radial outflow improved, Bolaven was upgraded to a 65-kt typhoon at 0000 UTC 17 November, centred approximately 480 nm east of Manila. (See Section E below.) Intensifying, Typhoon Bolaven quickly reached its peak intensity of 75 kts at 1200 UTC 17 November while located approximately 430 nm east of Manila. The peak MSW was maintained for only six hours and Bolaven began to weaken in the face of less favourable environmental conditions. Increasingly influenced by a steering ridge over southeast Asia, the tropical cyclone began to drift towards the west-northwest on 18 November. Bolaven was downgraded to a 60-kt tropical storm at 18/1800 UTC, being located approximately 320 nm east of Manila. Turning northwestwards, the system continued to weaken and made landfall over northeastern Luzon early on 20 November with the MSW estimated at around 40 kts. JTWC issued the final warning at 20/1200 UTC, six hours after downgrading Bolaven to a tropical depression. The system dissipated later that day. NMCC and PAGASA estimated a maximum intensity of 65 kts while JMA, HKO, CWB of Taiwan estimated a peak strength of 60 kts. JMA estimated a minimum CP of 976 mb. A graphic depicting the track of Typhoon Bolaven/Pepeng may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/w_pacific/BT-IMAGES/2005-24W-BOLAVEN.gif> C. Damages and Casualties ------------------------- There were no reports of damage or casualties associated with Typhoon Bolaven/Pepeng. D. Naga City Observations ------------------------- Michael V. Padua, or Naga City, Philippines, has sent me some weather observations made with his station. The highest daily rainfall was 41.7 mm on 18 November, while the storm total was 77.5 mm. The highest wind gust of 29 kts from the north was recorded at 09:30 AM local time on 18 November. The lowest barometric pressure of 1006.3 mb was recorded at 2:30 AM local time on 19 November. Weather Underground T2K AWS links (from Nov 17-19, 2005): http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=ICAMARIN2&month=11&day=17&year=2005> http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=ICAMARIN2&month=11&day=18&year=2005> http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=ICAMARIN2&month=11&day=19&year=2005> E. Additional Discussion ------------------------ Mark Lander posted an e-mail to a discussion list pointing out that the slow and erratic motion of Bolaven was in part due to a binary interaction with an unnumbered system to the northeast. That particular system was treated as a tropical depression by the Central Weather Bureau of Taiwan (CWB). The CWB track, sent by Huang Chunliang, follows. The CWB normally does not make wind estimations for tropical depressions. CWB Track for Tropical Depression (NRL Invest 99W) Date Press & & Time Status Wind(m/s) Position ====== ====== ========= ============ 111400 TD 1002/-- 14.0N 139.8E 111406 TD 1002/-- 13.4N 138.3E 111412 TD 1002/-- 15.8N 136.1E 111418 TD 1002/-- 16.9N 135.3E 111500 TD 1002/-- 17.5N 134.5E 111506 TD 1002/-- 18.0N 134.0E 111512 TD 1002/-- 18.0N 134.0E 111518 TD 1002/-- 18.5N 135.5E 111600 TD 1002/-- 20.5N 136.9E (Report written by Kevin Boyle, with additional information supplied by Michael V. Padua and Huang Chunliang) ************************************************************************* NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea Activity for November: 1 depression 1 cyclonic storm 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 ------------------------------------------------- The fairly active fall transitional season in the Bay of Bengal, which had seen one tropical cyclone in September and two in October, continued during the latter part of November with two systems tracked. The first was a tropical depression from 20-22 November which formed just east of Sri Lanka and moved erratically near the island, eventually crossing the northern tip. JTWC never issued any warnings on this system but did assigned a 'fair' potential for development. IMD treated it as a weaker depression with 25-kt winds, but the Thai Meteorological Depart- ment assigned a MSW of 30 kts for a couple of warning cycles. A graphic depicting the track of this system (NRL Invest 94B) may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/indian/BT-IMAGES/2005-94B-NONAME.gif> The other Bay of Bengal system was Cyclonic Storm Baaz, which formed late in the month in the east-central Bay and moved westward, becoming a 45-kt tropical storm but weakening into a depression before reaching India's southeastern coastline in early December. A report follows on Cyclonic Storm Baaz. CYCLONIC STORM BAAZ (BOB0503 / TC-05B) 27 November - 3 December -------------------------------------------- Baaz: contributed by Oman On 26 November an area of persistent convection had developed in the Bay of Bengal approximately 300 nm northwest of Penang, Malaysia. Animated satellite imagery indicated the possibility of a LLCC. An upper-level analysis showed increasing 850-mb vorticity and moderate vertical wind shear. The potential for development was assessed as 'poor', but this was upgraded to 'fair' in an interim STWO issued by JTWC at 27/0100 UTC. The system was then located about 500 nm northwest of Penang and deep convection was consolidating around a developing LLCC. Aloft, vertical shear was decreasing and divergence increasing. The disturbance continued to steadily develop and a TCFA was issued at 1200 UTC followed by the first JTWC warning on Tropical Cyclone 05B at 1800 UTC. The 30-kt center was then estimated to be located approximately 650 nm east of Madras, India, and was tracking westward at 10 kts along the southwestern periphery of a low to mid-level ridge. Also at 1800 UTC on the 27th, the Thai Meteorological Department (TMD) classified the system as a tropical depression and began issuing bulletins. The system continued moving generally westward across the Bay of Bengal and gradually intensified. By 28/1800 UTC the storm had reached its peak intensity of 45 kts (per JTWC's analysis) and was located about 425 nm east-southeast of Madras, India. The IMD had upgraded and named the system Cyclonic Storm Baaz by 28/1800 UTC. (The peak intensity estimated by IMD was also 45 kts.) Baaz continued moving on a west- northwestward track and maintained strength until the morning of 1 December, when it began to weaken due to increasing vertical wind shear. The storm's motion slowed and became somewhat erratic on 30 November as it neared the Indian coastline. JTWC issued their final warning on Baaz at 0600 UTC on 2 December, placing the completely- exposed center about 110 nm east-southeast of Madras. The TMD continued to track the depression until it had moved inland north of Pondicherry on 3 December. It is possible that Baaz was slightly stronger than indicated in the warnings from the various agencies. On 29 November SAB was assigning Dvorak intensity estimates of T3.5, or 55 kts. During its pre-tropical cyclone phase, the disturbance which became Cyclonic Storm Baaz (NRL Invest 96B) brought very heavy rain to southern Thailand. Ko Samui (WMO 48550) reported 417.0 mm during the 24-hour period ending at 25/0600 UTC. The rains brought destruction to southern Thailand. A preliminary report stated that 11 people were killed and hundreds of businesses destroyed. The preliminary damage estimate was around 400 million Thai baht, which is roughly 9 to 10 million U. S. dollars. (The rainfall information was from Huang Chunliang; the damage report from Phil Smith.) A graphic depicting the track of Cyclonic Storm Baaz may be found at the following link: http://www.tropicalcyclone2005.com/database/2005/indian/BT-IMAGES/2005-05B-BAAZ.gif> No reports of damage or casualties have been received from India in the region where the remnant depression made landfall. (Report written by Gary Padgett) ************************************************************************* SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E Activity for November: 2 tropical depressions ** 1 intense tropical cyclone ++ ** - one of these formed in the Western Australian region and was treated as a cyclone of gale intensity by JTWC ++ - system formed in the Western Australian region Southwest Indian Ocean Tropical Activity for November ----------------------------------------------------- Three tropical systems of depression intensity or stronger roamed South Indian Ocean waters west of 90E during November, but only one formed there. This system, numbered as Tropical Depression 03 by MFR, formed on 6 November a few hundred miles east-southeast of Diego Garcia and drifted southward for a couple of days before weakening, reaching an estimated intensity of 30 kts. JTWC issued a TCFA for this LOW, but never issued any warnings. A graphic depicting the track of this depression may be found at the following link: http://www.tropicalcyclone2005.com/database/2006/SOHEM/BT-IMAGES/2006-03R-NONAME.gif> Another system which had actually formed earlier in Australian waters east of 90E intensified into a tropical storm per JTWC's assessment and was designated TC-02S by that agency. BoM Perth, however, did not name the system as a tropical cyclone, and neither did Mauritius when it crossed 90E into the Southwest Indian Ocean proper. The system was already beginning to weaken when it crossed 90E, but MFR numbered it as Tropical Depression 04 and issued bulletins until it dissipated on 8 November. The other tropical system likewise formed in Perth's AOR and entered the Mauritius/La Reunion region, but this one became the first intense tropical cyclone of the season in the South Indian Ocean. Named Bertie by BoM Perth, the cyclone crossed 90E near its peak intensity of 100 kts and was renamed Alvin by Mauritius. Reports on TC-02S/MFR-04 and Intense Tropical Cyclone Bertie-Alvin follow in the next section of this summary covering the Northwest Australia/Southeast Indian Ocean region. ************************************************************************* NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E Activity for November: 1 tropical LOW ** 1 severe tropical cyclone ++ ** - system moved into the Southwest Indian Ocean basin and was treated as a cyclone of gale intensity by JTWC ++ - system moved into the Southwest Indian Ocean basin Sources of Information ---------------------- The primary sources of tracking and intensity information for Northwest Australia/Southeast Indian Ocean tropical cyclones are the warnings and advices issued by the Tropical Cyclone Warning Centres at Perth, Western Australia, and Darwin, Northern Territory. 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 the Australian centres' coor- dinates 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. For portions of the systems' histories lying west of longitude 90E, the following applies: 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 Tropical Cyclone Advisory Centres in Mauritius and Madagascar with longitude 55E being the demarcation line between their respective areas of naming 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. Northwest Australia/Southeast Indian Ocean Tropical Activity for November ------------------------------------------ Two tropical systems formed in waters between 90E and 135E during the month of November, both developing in the western part of the region and subsequently moving westward across 90E into the Southwest Indian Ocean basin. The first tropical LOW was unnamed by BoM Perth, but JTWC upgraded it to tropical storm intensity and numbered it TC-02S. After crossing 90E, RSMC La Reunion assumed official warning responsibility and numbered it as Tropical Depression 04, but neither that agency nor Mauritius considered it to be a tropical storm so it remained unnamed. The second system was Severe Tropical Cyclone Bertie, the first cyclone of the 2005-2006 to be named by any of the Australian TCWCs. Bertie became quite an intense cyclone in the vicinity of the 90th meridian and was renamed Alvin after crossing into the Southwest Indian Ocean proper. The reports on TC-02S/MFR-04 and Bertie-Alvin follow in this section of the summary since both originated east of 90E. TROPICAL DEPRESSION (MFR-04 / TC-02S) 5 - 8 November --------------------------------------- During the opening days of November the daily STWOs issued by BoM Perth began to hint of a weak LOW developing to the north and northwest of the Cocos Islands. Around 0400 UTC on 4 November a weak 1006-mb LOW was located about 230 nm north of the Cocos Islands and drifting south- westward at 6 kts. A STWO issued by JTWC at 04/0900 UTC also mentioned the system, noting that a tight LLCC was evident in animated multi- spectral imagery with increasing convection showing signs of wrapping into the center. The Perth TCWC initiated gale warnings on the LOW at 0400 UTC on 5 November, placing the center approximately 250 nm north of the Cocos Islands. Gales were not occurring at the time, but the LOW was forecast to develop into a tropical cyclone over the next 12 to 24 hours. JTWC issued a TCFA for the developing system at 05/0700 UTC. The tropical LOW continued to move on the southwesterly track which it would follow throughout its life. JTWC initiated warnings on TC-02S at 05/1800 UTC, noting that the LOW was located within an environment of moderate vertical shear with the deep convection remaining on the western periphery of the exposed LLCC. BoM Perth maintained the MSW at 30 kts while the system was located within their AOR, while JTWC's 1-min avg MSW estimates reached a peak of 45 kts at 06/0600 UTC with slow weakening thereafter. The minimum CP as estimated by Perth reached 995 mb on their final warning, issued at 06/1800 UTC. Normally a pressure this low is associated with a tropical cyclone, and JTWC and SAB were assigning Dvorak ratings of T3.0 on 6 November. It has occurred to the author that Perth's seeming reluctance to name this system was perhaps in part due to the fact that as it was about to cross 90E, it would be renamed, so it would almost be like "wasting" a name to name it then. However, the LOW was beginning to weaken as it crossed 90E, and neither MFR nor Mauritius regarded this system as a tropical storm. Hence, no name was ever assigned to the LOW, although it was designated Tropical Depression 04 by MFR. After crossing into the Southwest Indian Ocean proper around 0000 UTC on 7 November at a point about 465 nm west-southwest of the Cocos Islands, TD-04/TC-02S continued to march to the southwest as it slowly weakened. MFR downgraded the system to a tropical disturbance at 08/0600 UTC, and JTWC issued their final warning at the same time. MFR issued the final warning on the system at 08/1200 UTC, placing the center around 800 nm to the southeast of Diego Garcia. A graphic depicting the track of this system may be found at the following link: http://www.tropicalcyclone2005.com/database/2006/SOHEM/BT-IMAGES/2006-02S-04R-NONAME.gif> No damage or casualties are known to have resulted from this system. (Report written by Gary Padgett) TROPICAL CYCLONE BERTIE-ALVIN (MFR-05 / TC-03S) 18 - 28 November ------------------------------------------------- What was to become the first intense tropical cyclone of the season in the South Indian Ocean began as a weak tropical LOW on 17 November at a very low latitude near 3.0S/94.0E. In anticipation of the LOW's strengthening, BoM Perth began issuing gale warnings on the system at 0400 UTC on 18 November, placing the center approximately 575 nm north- northwest of the Cocos Islands. A few hours later JTWC issued a STWO, noting that convection was cycling around possible multiple LLCCs. An 18/1335 UTC SSM/I pass as well as animated water vapor imagery indicated the consolidation of the multiple LLCCs into a single center. The LOW steadily increased in organization, and at 19/0000 UTC was upgraded to Tropical Cyclone Bertie while located roughly 450 nm north- northwest of the Cocos Islands. For the next several days Bertie tracked southward and south-southwestward around the western periphery of a low to mid-level anticyclone centered between northwestern Australia and Sumatra. After a rather sluggish start, intensification began to proceed at a steady pace on the 20th with Bertie reaching severe tropical cyclone status (hurricane intensity) by 21/0000 UTC. The cyclone's track at this point became more southwesterly for about a day and a half before swinging back to an almost due southerly course as it neared the 90th meridian. The final warning from Perth was issued at 22/1200 UTC and estimated the MSW at 85 kts. Warning responsibility was shifted to MFR as it was anticipated that Bertie would have crossed 90E by the next warning cycle. MFR assumed warning responsibility for Bertie at 22/1800 UTC with the center still located just east of longitude 90E. The MSW was upped to its peak value of 100 kts with a CP of 930 mb. (JTWC's peak 1-min avg MSW estimate was 115 kts at 23/0600 UTC.) However, Bertie began to move due southward at this point with the center remaining less than 20 nm east of 90E. Since MFR had already assumed responsibility for issuing high seas warnings, they continued to do so even though it was not until 24/0000 UTC that Bertie's center finally edged west of the 90th meridian. Normally when a cyclone named by Australia moves into the Southwest Indian Ocean basin, Mauritius assigns a new name from the WMO Region I list of names, and a hyphenated name is applied for a period of 24 hours following the crossing, after which the Australian name is dropped. In the case of Bertie, Mauritius did not rename the system Alvin until the center had crossed 90E at 24/0000 UTC, even though the WMO Region I RSMC (La Reunion) had been issuing high seas warnings on the cyclone for more than a day. After crossing into the Southwest Indian Ocean basin, Tropical Cyclone Bertie-Alvin drifted to the southwest while slowly weakening. By 24/1800 UTC the cyclone's center had reached a point approximately 490 west-southwest of the Cocos Islands. This was as far south as Bertie-Alvin was to move--it then curved to a west-northwesterly course which it followed for the remainder of its life. This track carried the cyclone into an increasingly hostile environment of high vertical wind shear, and weakening was fairly rapid after 25/0000 UTC. The MSW was estimated at 80 kts at that hour--six hours later it was lowered to 55 kts. MFR reduced Tropical Storm Alvin to tropical depression status at 1200 UTC on 26 November and to a 25-kt tropical disturbance at 1800 UTC on the 27th. The weakening was even more dramatic based upon JTWC's warnings: at 24/1800 UTC that agency's 1-min avg MSW was still 100 kts. The final JTWC warning, issued 30 hours later, reduced the intensity to 30 kts. The La Reunion TCWC continued to issue warnings on ex-Tropical Storm Alvin through 28/1200 UTC when the final bulletin placed the weak center about 685 nm east-southeast of Diego Garcia. A graphic depicting the track of Tropical Cyclone Bertie-Alvin may be found at the following link: http://www.tropicalcyclone2005.com/database/2006/SOHEM/BT-IMAGES/2006-03S-01U-05R-BERTIE-ALVIN.gif> No damage or casualties have been attributed to Tropical Cyclone Bertie-Alvin. (Report written by Gary Padgett) ************************************************************************* 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: ftp://ftp.nhc.noaa.gov/pub/products/nhc/recon/> Information regarding how to interpret the coded reconnaissance messages may be found at the following URL: http://www.nhc.noaa.gov/reconlist.shtml> 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: http://www.nhc.noaa.gov/archive/2004/index.shtml> Links to tropical products archives for earlier years are available at the following URL: http://www.nhc.noaa.gov/pastall.shtml> JTWC warnings for past storms are archived on the NRL Monterry website: http://www.nrlmry.navy.mil/tc_pages/tc_home.html> 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: http://www.nrlmry.navy.mil/tc_pages/tc_home.html> http://cimss.ssec.wisc.edu/tropic/tropic.html> 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. Additional tropical satellite imagery, along with looping ability for composite microwave imagery for the Western Hemisphere north of the equator, can be found at: (1) For the Eastern North Pacific: http://www.ssd.noaa.gov/PS/TROP/trop-epac.html> (2) For the Atlantic, Gulf of Mexico and Caribbean Sea: http://www.ssd.noaa.gov/PS/TROP/trop-atl.html> 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): http://australiasevereweather.com/cyclones/> http://www.typhoon2000.ph> http://mpittweather.com> ftp://ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/> http://www.tropicalcyclone2005.com/> 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: http://www.metoffice.gov.uk/weather/tropicalcyclone> 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: http://199.10.200.33/jtwc.html> 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: http://www.nhc.noaa.gov> 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: [email protected] Phone: 334-222-5327 Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South China Sea) E-mail: [email protected] Simon Clarke (Northeast Australia/Coral Sea, South Pacific) E-mail: [email protected] ************************************************************************* *************************************************************************
Document: summ0511.htm
Updated: 19th March 2006 |
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