SUMMARY: August TC Summary - Part 3

From: Gary Padgett (garyp@ALAWEB.COM)
Date: Wed Nov 22 2006 - 17:44:54 EST


 

 

  _____

From: Gary Padgett [mailto:garyp@alaweb.com]
Sent: Wednesday, November 22, 2006 4:43 PM
To: Alexandre Aguiar; Alipate Waqaicelua; Brent Reynolds (WX); Bruno
Benjamin; David A. Marshall; David C. Worrall; David Roth; Douglas Jones;
Fred Joines; Jack A. Cross III; Jason McDonald; Jay K. Moyer; Jean Marc de
Maroussem; Jim Parsons; Joel W. Newton (Work); John K. Webb; Karl Hoarau;
Kevin Boyle; Leon K. Curenton; Luiz E. Gava; Mark Kersemakers; Michael V.
Padua (TCDG); Pablo G. Dejesus; Patrick Hoareau; Philip Garrett; Richard B.
Risner; Robert F. Boyle; Todd R. Tuckey; Walt Peterson
Subject: August TC Summary - Part 3

 

 

                   MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY

 

                                AUGUST, 2006

                              Third Installment

 

  SPECIAL NOTE: The August summary is being issued in three installments.

  The first one covered the Atlantic basin and contained an extra feature

  while the second covered the Northeast Pacific basin. This third and

  final installment covers the Northwest Pacific and North Indian Ocean

  basins.

 

  NOTE FROM THE AUTHOR: Almost two years ago I began including links to

  track graphics prepared by John Diebolt of Tucson, Arizona, and archived

  on his tropical cyclone website. A few months back John experienced a

  disk crash which resulted in a error. He had to request assistance from

  the programmer who had written the map-generation software, but so far

  has not been able to get the problem solved. As a convenience to users,

  I've also recently been including links to the individual tabular tracks,

  prepared by myself, which John had archived on his website. Now, due to

  family issues, John has not had time to place the tracks for the August

  cyclones on the website. I have checked the websites listed at the end

  of the summaries and found that the entire August track file has been

  archived on two of them. The links are:

 

  http://australiasevereweather.com/cyclones/2007/trak0608.htm

 

  http://www.typhoon2000.ph/garyp_mgtcs/aug06tks.txt

 

  (For general comments about the nature of these summaries, as well as

  information on how to download the tabular cyclone track files, see

  the Author's Note at the end of this summary.)

 

  *************************************************************************

 

                             AUGUST HIGHLIGHTS

 

   --> Atlantic rather quiet--tropical storm affects Haiti, Cuba, Florida

       and U. S. Eastern Seaboard

   --> Eastern North Pacific very active--one hurricane adversely affects

       the Baja California Peninsula

   --> Extremely long-lived Central and Western Pacific major hurricane/

       super typhoon strikes both Johnston and Wake Islands

   --> Western North Pacific very active--China experiences very rare

       strike by a destructive super typhoon

   --> Several weak depressions in Bay of Bengal

 

  *************************************************************************

  

                            ACTIVITY BY BASINS

 

  ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico

 

  Activity for August: 2 tropical storms

                        1 hurricane

 

 

  NOTE!!! The Atlantic basin was covered in the first installment of the

          August summary.

 

  *************************************************************************

 

  NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180

 

  Activity for August: 2 tropical storms

                        2 hurricanes

                        3 major hurricanes **

 

  ** - one of these formed in Central North Pacific and became a Western

       Pacific super typhoon

 

 

  NOTE!!! The Northeast Pacific basin was covered in the second installment

          of the August summary.

 

  *************************************************************************

 

  NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180

 

  Activity for August: 3 tropical depressions **

                        3 tropical storms

                        2 typhoons ++

                        2 super typhoons &&

 

  ** - two of these were classified as weak depressions by JMA only

 

  ++ - one of these formed in late July and continued into early August

 

  && - one of these was a visitor from the Central North Pacific and

       continued into early September

 

 

                          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 August

               ----------------------------------------------

 

     The tropical Western Pacific was very active during the first half

  of August with five named storms forming within a 9-day period. In

  addition, during the first few days of the month Typhoon Prapiroon,

  which had formed at the end of July, was active in the northern South

  China Sea where it made landfall in southern China on the 3rd. The

  complete report on Prapiroon may be found in the July summary.

 

     Maria was a storm of higher-latitude origin which managed to reach

  minimal typhoon intensity (per JTWC's analysis). Maria later recurved

  sharply just south of Honshu and brushed the southern coast of that

  island as it accelerated northeastward. Super Typhoon Saomai and

  Tropical Storm Bopha both formed in the monsoon trough at about the same

  time of Maria's genesis, and all three cyclones operated concurrently

  for a few days. Bopha remained a fairly weak tropical storm as it moved

  westward toward Taiwan. The large, intense Saomai gave the weakening

  Bopha a push which sent it moving southwestward into the northern South

  China Sea. Saomai followed a classic 'straight-runner' track from deep

  in the tropics west-northwestward through the Marianas, passing just

  north of Taiwan, and finally smashing into eastern China still at super

  typhoon intensity. Saomai was reported to be the strongest typhoon to

  strike the Chinese mainland in modern times. More than 400 persons lost

  their lives with damage in the billions of yuan.

 

     Wukong and Sonamu were two tropical storms spawned by a large

  monsoon gyre. Wukong, the stronger of the two, formed just west of

  the Marianas and followed a generally northwesterly, albeit erratic,

  track toward Japan. The storm eventually crossed the island of Kyushu

  and moved up the eastern side of the Korean Peninsula. Tropical Storm

  Sonamu formed just east of northern Luzon and moved fairly rapidly

  northeastward, later swinging to the north as it underwent a Fujiwhara

  interaction with Wukong. As it neared Japan, Sonamu weakened and was

  absorbed into Tropical Storm Wukong.

 

     On 27 August a visitor from the Central North Pacific, Category 5

  Hurricane Ioke, entered the Northwest Pacific basin. Designated as

  Super Typhoon Ioke, the large, intense cyclone continued on a west-

  northwesterly track toward tiny Wake Island. Ioke passed just north

  of the island on the 31st and continued moving in the general direction

  of Japan as it slowly began to weaken. The cyclone eventually recurved

  east of Honshu and became extratropical on 5 September with the remnants

  later affecting the Aleutian Islands and Alaska. The complete report

  on Ioke was contained in the second installment of the August summary

  covering the Northeast Pacific basin.

 

     There were three weaker systems during the month classified as

  tropical depressions by the various warning agencies. Two of these

  were mentioned only in JMA's high seas bulletins as weak systems. Both

  formed and moved north of 30N, suggesting that they were likely

  subtropical in nature. The first was located near 30.0N/174.0E at

  15/0600 UTC and moved very slowly westward, being last referenced near

  31.0N/170.0E at 17/1800 UTC. The second system was located at 21/1800

  UTC near 33.0N/155.0E. Twenty-four hours later the final reference to

  this system placed it near 34.0N/152.0E. Winds in these systems likely

  did not exceed 20-25 kts and no tracks were given in the companion

  cyclone tracks file.

 

     The final system of August was a short-lived tropical depression

  designated as TD-13W by JTWC and carried by JMA and some of the other

  warning offices. The depression formed in the northern South China

  Sea on 23 August and moved generally northward, moving inland in

  China between Hainan and Hong Kong around 24/1800 UTC. The peak MSW

  estimated by JTWC was 30 kts at 24/1800 UTC, shortly before the center

  made landfall. In JMA's high seas bulletins the depression was

  referenced only in the summary section, implying 10-min avg winds of

  probably no higher than 25 kts. A track was included for TD-13W in

  the cyclone tracks file.

 

     Reports for Typhoon Maria, Super Typhoon Saomai, and Tropical Storms

  Bopha, Wukong and Sonamu, all written by Kevin Boyle, follow. Reports

  on Typhoon Prapiroon and Super Typhoon Ioke may be found elsewhere, as

  noted above.

 

     The online Wikipedia reports for the Northwest Pacific cyclones may

  be accessed at the following URL:

 

  http://en.wikipedia.org/wiki/2006_Pacific_typhoon_season

 

  A more detailed report is available for Super Typhoon Saomai/Juan.

  The link is included in the report for that cyclone.

 

 

 

                              TYPHOON MARIA

                           (TC-09W / STS 0607)

                              4 - 12 August

                 ---------------------------------------

 

  Maria: contributed by the United States, is the Latin/Hispanic form

         of Mary and is popular as a Chamorro woman's name

 

  A. Storm Origins

  ----------------

 

     The second of six tropical cyclones during the month of August, Maria

  was a TUTT-induced tropical cyclone that formed at a fairly high

  latitude. After its initial mention in JTWC's STWO on 3 August, the

  system slowly developed over the next two days while drifting towards

  the west-northwest, and at 1630 UTC 5 August a TCFA was issued. (JMA

  had started the system as a weak tropical depression at 04/0000 UTC

  while located approximately 400 nm east-northeast of the northern

  Mariana Islands and had upped the MSW to 30 kts six hours later.)

  Remarks in JTWC's TCFA include: ". . . recent animated satellite imagery

  depicts a dramatic flare-up in deep convection slightly east of a

  well-defined low level circulation center. Further satellite analysis

  indicates that despite this increase in convective organization this

  system still exhibits characteristics of a subtropical cyclone. Upper-

  level analysis reveals low to moderate vertical wind shear and

  favourable diffluence aloft. . ." The first warning on Tropical

  Depression 09W was issued at 1800 UTC 5 August with the centre located

  approximately 150 nm east-northeast of Iwo Jima. The system had been

  named Maria at 05/1200 UTC when JMA raised their 10-min avg MSW to

  35 kts.

 

 

  B. Synoptic History

  -------------------

 

     Continuing west-northwestwards along the southwestern flank of a

  broad subtropical ridge east of Japan, Maria was quickly upgraded to

  a 40-kt tropical storm at 06/0000 UTC and relocated to a position

  150 nm north-northeast of Iwo Jima. Tropical Storm Maria intensified

  as it moved northwestwards and reached 60 kts at 06/0600 UTC. A

  06/1045 UTC SSMI pass depicted a symmetric banding eye with deep

  convection over the eastern semicircle. Maria was upgraded to a 65-kt

  typhoon at 07/1200 UTC while located approximately 305 nm south-southwest

  of Tokyo, Japan, but maintained this intensity for only six hours.

  Turning northward on 8 August, Maria began to weaken as it encountered

  drier air and increasing wind shear. After recurving sharply just shy

  of the southeastern coast of Honshu, the weakening tropical cyclone

  passed just south of Tokyo early on 9 August. JTWC issued the final

  warning at 09/0000 UTC while JMA maintained Maria's identity as a

  tropical cyclone until 11/0000 UTC when that agency issued their final

  bulletin. The system was then located about 450 nm east-northeast of

  Tokyo. The remnant extratropical gale continued slowly east-

  northeastward, and was last referenced in JMA's high seas bulletins at

  12/1200 UTC when located several hundred miles east of Hokkaido.

 

     The maximum 10-min avg MSW assigned by JMA for Maria was 60 kts and

  the estimated minimum CP was 975 mb.

 

 

  C. Damage and Casualties

  ------------------------

 

     There were no reports of damages or casualties associated with Maria.

  A tidbit of information obtained from the Hong Kong Observatory's

  Overview of Tropical Cyclones in August, 2006, indicated that five

  passengers were injured when an aircraft heading for Tokyo encountered

  turbulence associated with Maria.

 

  (Report written by Kevin Boyle)

 

 

 

                           SUPER TYPHOON SAOMAI

                        (TC-08W / TY 0608 / JUAN)

                               4 - 11 August

              ---------------------------------------------

 

  Saomai: contributed by Vietnam, is the Vietnamese name for the planet

          Venus

 

  A. Introduction and Storm Origins

  ---------------------------------

 

     Super Typhoon Saomai co-existed with two other tropical cyclones in

  the Northwest Pacific during the first part of August and was by far

  the most intense. Forming in the eastern portion of the monsoon trough

  on 4 August, Saomai followed a "straight-runner" style track across the

  Northwest Pacific basin and underwent a binary interaction with Tropical

  Storm Bopha (TC-10W). Saomai, much larger than Bopha, was little

  affected by this interaction, and continued its west-northwestward track

  into China on 10 August. It was described as the most powerful typhoon

  ever to make landfall over mainland China, and was the strongest to hit

  the country since Typhoon Wanda in 1956. Its impact was devastating,

  especially in the areas already badly hit by Tropical Storm Bilis and

  Typhoon Kaemi in July.

 

     First mention of this monstrous storm was in JTWC's STWO issued at

  0600 UTC 2 August when an area of convection persisted approximately

  125 nm south-southeast of Pohnpei. This statement in part: "Animated

  multi-spectral imagery reveals a strong band of convergent westerly

  flow on the southern periphery of an elongated low-level circulation

  center. This convergent axis has been the focal point for deep

  convection over the last 12 hours. The disturbance is located on the

  equatorward side of an upper-level ridge axis in a region of favorable

  divergence aloft and moderate vertical wind shear." The system slowly

  organized as it drifted steadily northwestwards, and after the issuance

  of a TCFA on 4 August, the first warning on Tropical Depression 08W was

  issued at 1800 UTC 4 August. It was upgraded to a 35-kt tropical storm

  at 05/0600 UTC, and named Saomai six hours later when JMA raised their

  10-min avg MSW to 35 kts. At the time Tropical Storm Saomai was

  located 135 nm southeast of Guam, moving northwestward at 11 kts.

 

 

  B. Synoptic History

  -------------------

 

     Drifting northwestwards, Tropical Storm Saomai slowly intensified and,

  after passing just north of Guam late on 5 August, was upgraded to a

  65-kt typhoon at 1200 UTC 6 August. Changing onto a west-northwesterly

  track, Saomai continued to gradually strengthen, reaching an intensity

  of 75 kts on 7 August. As Typhoon Saomai approached the southern Ryukyu

  Islands late 8 August, it began to intensify more rapidly, reaching its

  peak intensity of 140 kts at 09/1200 UTC and becoming the third super

  typhoon of 2006 in the Northwest Pacific basin. Remarkably, Saomai

  maintained its maximum intensity until early on 10 August before slowly

  beginning to weaken. Turning westward, Typhoon Saomai passed north of

  Taiwan and crossed the Chinese coast near Fu'an at 10/0923 UTC (based on

  an AMSU pass) with the MSW estimated at 130 kts. Once inland, the

  tropical cyclone weakened quickly. The final warnings were issued by

  JTWC and JMA at 10/1800 UTC and 11/0000 UTC, respectively.

 

     During the time that Typhoon Juan was in PAGASA's AOR, the peak MSW

  (10-min avg) assigned by that agency was 75 kts from 09/0000 to 09/0600

  UTC. JMA estimated a peak intensity of 95 kts (10-min avg) with a

  minimum CP of 925 mb.

 

 

  C. Damage and Casualties

  ------------------------

 

     As was the case with Tropical Storm Bilis in July, the outer

  rainbands from Saomai affected portions of the Philippines. Over 400

  homes were reported destroyed by storm surge, and there were two

  fatalities with seven others reported missing.

 

     The strong core of Super Typhoon Saomai passed to the north of

  Taiwan, but the island still experienced heavy rain and wind that

  disrupted traffic and resulted in cancelled airline flights.

 

     By far the biggest impact of the typhoon was felt on the Chinese

  mainland where 441 deaths were reported and damage exceeding $1.5

  billion (USD) was sustained. In advance of Saomai's arrival over 1.5

  million people were evacuated to storm shelters in Zhejiang and Fujuan

  Provinces. Even though the storm's center made landfall in Zhejiang

  Province, the neighboring province of Fujian sustained even greater

  damage and experienced more fatalities. Two persons were reported

  killed in Jiangxi Province.

 

     Much more information on the effects of Typhoon Saomai in China

  may be found in the online Wikipedia report at the following URL:

 

  http://en.wikipedia.org/wiki/Typhoon_Saomai_%282006%29

 

  (Report written by Kevin Boyle and Gary Padgett)

 

 

 

                           TROPICAL STORM BOPHA

                        (TC-10W / STS 0906 / INDAY)

                              5 - 11 August

              -----------------------------------------------

 

  Bopha: contributed by Cambodia, is the name of a flower which is used

         as a little girl's name

 

  A. Storm Origins

  ----------------

 

     Tropical Storm Bopha was one of three tropical cyclones co-existing

  in the Northwest Pacific basin during the first week of August. It

  reached a peak intensity of 50 kts before crossing Taiwan on 8 August.

  Interaction with Super Typhoon Saomai caused Bopha to dip sharply

  southwestwards before it dissipated on 10 August. (Editor's Note: The

  other two simultaneous TCs in addition to Bopha were Super Typhoon Saomai

  and Typhoon Maria. Interestingly, in September, 2000, Tropical Storm

  Bopha and Super Typhoon Saomai were also part of a simultaneous three-

  storm outbreak, but in that year the third member of the party was

  Typhoon Wukong.)

 

     An area of convection developed and persisted about 560 nm

  southeast of Okinawa on 4 August. The flare-up of convection was

  association with surface troughing, and an upper-level anticyclone was

  located over the disturbance with low vertical shear over the region.

  The system was first referenced in JTWC's STWO at 2200 UTC 4 August, and

  JMA classified the system as a weak tropical depression in their high

  seas bulletin issued at 05/0600 UTC. A later STWO issued at 06/0600 UTC

  remarked: "Recent multi-spectral imagery and a 05/2330 UTC SSMI pass

  depict a well-defined low-level circulation center with deep convection

  located 90 nm east of the center. Upper-level analysis indicates a

  favourable environment with weak (5-10 kts) vertical wind shear. A

  synoptic ship report 120 nm southwest of the center indicated a 1002 mb

  SLP". The first warning on Tropical Depression 10W closely followed

  this statement at 06/0600 UTC and located the centre approximately

  320 nm southeast of Naha, Okinawa. At the same time JMA raised their

  10-min MSW to 35 kts and named the system Bopha.

 

 

  B. Synoptic History

  -------------------

 

     Drifting west-northwestward at 8 kts, Tropical Depression Bopha was

  upgraded to a 40-kt tropical storm at 06/1200 UTC. After further

  intensification, Bopha reached its maximum intensity of 50 kts at 0600

  UTC 7 August while passing 200 nm south of Naha, Okinawa. At this time,

  Typhoon Saomai was tracking steadily west-northwestward and was located

  a little over 600 nm to the east of Bopha.

 

     Embedded in the steering flow south of a deep-layer ridge to the

  north, Bopha continued westward and began to gradually weaken due to

  increasing wind shear. By the time the storm made landfall over Taiwan

  late on 8 August, the MSW had dropped to 35 kts. After clearing Taiwan,

  Bopha was downgraded to a tropical depression at 09/0600 UTC.

  Influenced by the larger circulation of Super Typhoon Saomai, the weak

  tropical cyclone then made a sharp southwestward turn a little over

  100 nm east-southeast of Hong Kong, China. The fully-exposed LLCC then

  began to meander slowly westwards on 10 August. The final JTWC warning

  on the dissipating system was issued at 10/1200 UTC, while JMA continued

  to follow the weakening depression through 11/0000 UTC when it was

  located very near Hong Kong.

 

     The highest MSW and lowest CP estimated by JMA were 50 kts and 985 mb,

  respectively. During the time that Bopha was within PAGASA's AOR, where

  it was known as Tropical Storm Inday, the peak 10-min avg MSW estimated

  by that agency was 45 kts.

 

 

  C. Damage and Casualties

  ------------------------

 

     Even though Bopha affected Taiwan, there were no reports of damage or

  casualties.

 

  (Report written by Kevin Boyle)

 

 

 

                          TROPICAL STORM WUKONG

                            (TC-11W / TS 0610)

                               12 - 21 August

                -----------------------------------------

 

  Wukong: contributed by China, is the king of the monkeys. Featured in

          the classic novel 'Journey to the West'.

 

  A. Introduction and Storm Origins

  ---------------------------------

 

     Tropical Storm Wukong was one of two tropical cyclones generated by a

  monsoon gyre in the northwest Pacific during mid-August. After peaking

  at 50 kts and interacting with Tropical Storm Sonamu and absorbing its

  remnants, Wukong made landfall over Kyushu. It took over 24 hours for

  the tropical cyclone's circulation to cross the Japanese island.

 

     Tropical Storm Wukong stemmed from a disturbance located in the

  monsoon cloud band which had wrapped around the northern side of a gyre.

  Remarks in JTWC's TCFA at 0230 UTC 12 August include: "Recent animated

  multi-spectral imagery reveals a consolidating low-level circulation

  center (LLCC), and a 12/0000 UTC synoptic ship observation report

  indicates winds associated with the LLCC to be at least 20 knots.

  Upper-level analysis indicates favorable outflow into a Tropical Upper-

  Tropospheric Trough (TUTT) cell to the northwest of the LLCC, as well

  as low vertical wind shear." The system was moving northwestward at

  9 kts with a MSW of 20 to 25 kts. The first warning on Tropical

  Depression 11W at 12/1200 UTC positioned the centre approximately 75 nm

  south of Iwo Jima. Tracking north-northwestward, TD-11W was upgraded

  to a 35-kt tropical storm at 13/0000 UTC and named Wukong six hours

  later when JMA raised their 10-min avg MSW to 35 kts.

 

 

  B. Synoptic History

  -------------------

 

     Tropical Storm Wukong slowed dramatically on 13 August as a ridge

  built eastward over Japan. Slow, erratic movement persisted through

  14 August as the tropical cyclone gradually strengthened to its peak

  intensity of 50 kts at 14/1800 UTC while located approximately 545 nm

  southeast of Sasebo, Japan. Wukong began to accelerate to the north-

  northwest on 15 August while commencing a binary interaction with

  Tropical Storm Sonamu (TC-12W). This interaction caused Wukong to

  drift west-southwestwards on 16 August. After the demise of TS Sonamu,

  Wukong turned back to the northwest as a weakness developed in the

  steering ridge. The system maintained a MSW of 45 kts for two days as

  it continued slowly northwestwards towards Japan. Tropical Storm Wukong

  made landfall near Miyazaki city and trudged slowly across the Japanese

  island of Kyushu on 18 August. The storm remained over land for over

  24 hours and did not emerge into the Sea of Japan until 19 August. JTWC

  downgraded Wukong to a tropical depression at 18/0600 UTC and issued the

  last warning at 19/0000 UTC. JMA maintained tropical storm intensity on

  19 August as Wukong brushed the eastern coasts of North/South Korea,

  downgrading it to tropical depression status at 20/1200 UTC. The weak

  residual depression drifted northeastwards across the Sea of Japan and

  was last referenced at 21/1800 UTC when located west of extreme

  southern Hokkaido.

 

     The maximum 10-min avg MSW and minimum CP estimated by JMA were

  45 kts and 980 mb, respectively.

 

 

  C. Damage and Casualties

  ------------------------

 

     On 18 August Tropical Storm Wukong brought torrential rains to

  Kyushu, resulting in at least three deaths, disruption of air flights,

  and power outages.

 

  (Report written by Kevin Boyle)

 

 

 

                           TROPICAL STORM SONAMU

                        (TC-12W / TS 0611 / KATRING)

                               13 - 16 August

              ------------------------------------------------

 

  Sonamu: Korean word for pine tree, contributed by the Democratic

          People's Republic of Korea (North Korea)

 

  A. Introduction and Storm Origins

  ---------------------------------

 

     Tropical Storm Sonamu was a relatively short-lived tropical cyclone

  which was generated on the southern flank of a monsoon gyre. Embedded

  in a rather strong steering flow, Sonamu raced northeastwards and

  peaked at 45 kts. Interaction with Tropical Storm Wukong (TC-11W)

  caused the tropical cyclone to weaken and dissipate several hundred

  miles southeast of Japan.

 

     A Tropical Cyclone Formation Alert issued at 1730 UTC 13 August noted

  that the area of convection was located approximately 430 nm east-

  northeast of Manila, Philippines, and moving slowly eastward at 4 kts.

  Animated infrared imagery revealed enhanced convection consolidating

  near an elongated LLCC. Upper-level analysis indicated favourable

  divergence and low to moderate wind shear. Accelerating eastwards, the

  system developed into Tropical Depression 12W at 13/1800 UTC. It was

  named Sonamu at 14/0000 UTC after JMA raised their MSW estimate to

  35 kts. JTWC upgraded Sonamu to a 40-kt tropical storm six hours later

  when the system was centred approximately 500 nm south-southeast of

  Okinawa.

 

 

  B. Synoptic History

  -------------------

 

     Tropical Storm Sonamu was steered northeastwards around the periphery

  of the monsoon gyre and strengthened to its peak intensity of 45 kts at

  1800 UTC 14 August while located approximately 485 nm southeast of

  Naha, Okinawa. The storm began to weaken on 15 August as it turned

  northeastward and began to interact with the almost stationary

  Tropical Storm Wukong (TC-11W), located to the north-northwest. After

  satellite imagery revealed that shear associated with the outflow of

  Wukong had dramatically decreased the deep convection over Sonamu, JTWC

  downgraded the system to a tropical depression at 15/1800 UTC. JTWC

  issued the final warning at 16/0000 UTC on the dissipating tropical

  cyclone which was racing north at 32 kts and about to be absorbed into

  the circulation of Tropical Storm Wukong just south of Japan.

 

     JMA estimated a maximum intensity of 40 kts (10-min avg) and a minimum

  CP of 992 mb while PAGASA issued warnings on Tropical Storm Katring

  (the PAGASA name) from 13/1800 UTC to 15/0000 UTC and estimated a peak

  intensity of 35 kts (10-min avg).

 

 

  C. Damage and Casualties

  ------------------------

 

     No damage or casualties are known to have resulted from Tropical

  Storm Sonamu.

 

  (Report written by Kevin Boyle)

 

  *************************************************************************

 

  NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea

 

  Activity for August: 3 depressions

                        1 deep depression

 

 

               North Indian Ocean Tropical Activity for August

               -----------------------------------------------

 

     The month of August normally is one of the quietest in the Bay of

  Bengal and Arabian Sea, falling in between the more active periods of

  the spring and fall transition seasons. Nonetheless, four systems were

  classified as depressions by the India Meteorological Department (IMD)

  during the month. The first was classified as a deep depression,

  implying winds of 30 kts, whereas the other three were referred to as

  simply depressions, implying winds no greater than 25 kts. A brief

  synopsis of each system follows:

 

  (1) Deep Depression of 1 - 5 August

  -----------------------------------

 

     A STWO issued by JTWC at 1800 UTC on 1 August noted that an area of

  convection had persisted a couple hundred miles south-southeast of

  Calcutta. Animated multi-spectral imagery and a 01/1248 UTC QuikScat

  pass revealed that the LLCC of a monsoon depression had moved over

  water in the northern Bay of Bengal. Strong northeasterly winds aloft

  were inducing high vertical shear over the area, but were also providing

  a good outflow mechanism for convective development. The system moved

  westward across the northern Bay, and the IMD had classified it as a

  depression by 02/0300 UTC when the center was located approximately

  55 nm east-southeast of Chandbali. At 02/1200 UTC the IMD had upped

  the system's classification to 'deep depression', implying winds of

  30 kts. Around the same time JTWC upped the potential for development

  to 'fair'. The center of the deep depression was near the Indian

  coastline at that time, and by 0300 UTC the next day was moving inland

  on the South Orissa coast between Puri and Gopalpur.

 

     IMD followed the system inland for a couple of days as it moved into

  central India. The peak winds were maintained at 30 kts for 24 hours

  after the center had crossed the coast, suggesting that the system had

  maintained much of its monsoon depression characteristics throughout

  its lifetime. A track for this system was included in the companion

  cyclone tracks file.

 

  (2) Depression of 12 - 13 August

  --------------------------------

 

     The second depression formed on 12 August and at 0300 UTC lay centered

  about 55 nm east-southeast of Balasore. The system moved in a west-

  northwesterly direction and crossed the North Orissa coast near Balasore

  around 1500 UTC. By 13/0300 UTC it had weakened into a low-pressure area

  near Chattisgarh. This system was not referenced in any of JTWC's STWOs.

 

  (3) Depression of 16 - 18 August

  --------------------------------

 

     The third depression of August formed on 16 August in the same general

  area as the previous one, being centered at 16/0300 UTC about 80 nm

  southeast of Balasore. The system subsequently moved westward and crossed

  the North Orissa coast near Chandbali around 16/1450 UTC. After moving

  inland the depression gradually weakened and was last referenced by

  IMD at 0300 UTC on 18 August. JTWC mentioned this system in their STWOs,

  assigning a 'fair' potential for development at one point, but this was

  downgraded to 'poor' at 16/1800 UTC when the broad center was observed

  to be moving inland.

 

  (4) Depression of 29 August - 1 September

  -----------------------------------------

 

     The final depression to form in the northwestern Bay of Bengal during

  August was located at 29/0300 UTC about 55 nm east-southeast of

  Chandbali. The system moved rapidly west-northwestward and by 1200 UTC

  had crossed the Orissa coast near Parandip. IMD continued following the

  LOW inland across eastern and central India, last referencing it on

  1 September when it was in the vicinity of Agra.

 

     In the companion global cyclone tracks file prepared by the author,

  a track was included for only the first of the NIO depressions. The

  primary criterion for inclusion in the tracks file is reasonable evidence

  of the existence of 1-min avg sustained winds of 30 kts or higher, either

  reported by a warning agency or else a consensus of Dvorak ratings of

  T2.0 or higher. IMD classified the latter three systems only as

  'depressions', implying winds no higher than 25 kts.

 

  *************************************************************************

 

  SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E

 

  Activity for August: No tropical cyclones

 

  *************************************************************************

 

  NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E

 

  Activity for August: No tropical cyclones

 

  *************************************************************************

 

  NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E

 

  Activity for August: No tropical cyclones

 

  *************************************************************************

 

  SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E

 

  Activity for August: No tropical cyclones

 

  *************************************************************************

 

         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 Monterrey 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://www.typhoon2000.ph/>

    http://mpittweather.com <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: https://metocph.nmci.navy.mil/jtwc.html

 

 

     Also, TPC/NHC has available on its webpage nice "technicolor"

  tracking charts for the 2005 Atlantic and Eastern North Pacific

  tropical cyclones; also, storm reports for all the 2005 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 <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: garyp@alaweb.com

  Phone: 334-222-5327

 

  Kevin Boyle (Northwest Pacific)

  E-mail: newchapelobservatory@btinternet.com

 

  Simon Clarke (Northeast Australia/Coral Sea, South Pacific)

  E-mail: scla4255@bigpond.net.au

 

  *************************************************************************

  *************************************************************************

 

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