[Index]
Monthly Global Tropical Cyclone Summary September 2003
[Summaries and Track Data] [Prepared by Gary Padgett]
| Tropical
Cyclones
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Monthly Global Tropical Cyclone Summary September 2003 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
SEPTEMBER, 2003
(For general comments about the nature of these summaries, as well as
information on how to download the tabular cyclone track files, see
the Author's Note at the end of this summary.)
*************************************************************************
SEPTEMBER HIGHLIGHTS
--> Long-lived intense Cape Verde hurricane makes devastating strike on
U. S. East Coast--still a tropical storm in Ontario, Canada
--> Nova Scotia experiences significant hurricane damage
--> Another hurricane strikes the Baja California Peninsula and moves up
entire Gulf of California
--> Very deadly and devastating typhoon strikes South Korea
--> Unusually early-season tropical storm forms in Southwest Indian Ocean
*************************************************************************
***** Feature of the Month for September *****
SOUTHERN HEMISPHERE TROPICAL CYCLONE NAMES
2003 - 2004 SEASON
TROPICAL CYCLONE NAMES for the AUSTRALIAN REGION
The Australian Bureau of Meteorology maintains three Tropical
Cyclone Warning Centres (TCWC): Perth, Western Australia; Darwin,
Northern Territory; and Brisbane, Queensland. Each centre is allotted
a separate list of tropical cyclone names for tropical cyclones forming
within its area of responsibility (AOR). In addition a TCWC located at
Port Moresby, Papua New Guinea (PNG)--a former Australian territory--
maintains a list of native names to assign to the very rare tropical
cyclones which form within its AOR.
The AORs of the respective centres are:
(1) Perth - 125E westward to 90E and south of 10S. Currently, and for
at least the next few years, the Perth TCWC will issue warnings for
any systems north of 10S and south and west of the Indonesian
islands.
(2) Darwin - 125E eastward to 138E and extending northward to the
equator. There is a little irregularity with the eastern border
in the Gulf of Carpentaria. The Darwin TCWC issues High Seas
Warnings for the entire Gulf of Carpentaria, but Brisbane issues
Tropical Cyclone Advices and names cyclones in the eastern portion
of the Gulf. Also, currently, and for at least the next few years,
the Darwin TCWC will issue warnings for any systems west of 125E
and within the Indonesian archipelago in the Banda, Flores, and
Java Seas.
(3) Brisbane - 138E eastward to 160E and generally south of 10S. The
northern border with the Port Moresby AOR is somewhat irregular.
(4) Port Moresby, PNG - immediate vicinity of the island of New Guinea
and eastward to 160E generally north of 10S although the southern
border is somewhat irregular.
Names for the 2003-2004 season (** indicates name has already been
assigned):
Perth Darwin Brisbane Port Moresby
-----------------------------------------------------------------------
Jana ** Debbie ** Fritz Guba
Ken ** Evan Grace Ila
Linda Fay Harvey Kama
Monty George Ingrid Matere
Nicky Helen Jim Rowe
Oscar Ira Kate Tako
Phoebe Jasmine Larry
Raymond Kim Monica
Sally Laura Nelson
Tim Matt Odette
Vivienne Pierre
Willy Rebecca
Adeline Sandy
Bertie Tania
Clare Vernon
TROPICAL CYCLONE NAMES for the SOUTHWEST INDIAN OCEAN
and the SOUTH PACIFIC OCEAN
The Tropical Cyclone Warning Centre (TCWC) at Nadi, Fiji, has
tropical cyclone warning responsibility for the South Pacific east of
160E and from the equator to 25S. The Meteorological Service of New
Zealand at Wellington has warning responsibility for waters south of
25S, but almost all tropical cyclones in this basin form north of 25S.
When a rare cyclone forms in the Wellington area of responsibility
(AOR), it usually will be assigned a name from the Fiji list (such as
was done for Tropical Cyclone Gita in February, 1999.)
Tropical cyclone warning responsibility for South Indian waters west
of 90E are shared by several TCWCs. The Regional Specialty
Meteorological Centre (RSMC) for the region is the office of Meteo
France on the island of La Reunion. However, following a long-standing
practice, the sub-regional centres at Mauritius and Madagascar share
the responsibility for actually naming tropical storms with Mauritius
naming systems east of 55E and Madagascar covering the area west of
55E. RSMC La Reunion issues warnings for the basin independently of
these sub-regional centres, but only advises regarding when or when not
to assign a name to a developing cyclone.
Names for the 2003-2004 season (** indicates name has already been
assigned):
Southwest Indian South Pacific
-----------------------------------------------------------------------
Abaimba ** Naledi Heta ** Sheila
Beni ** Olie Ivy Tam
Cela ** Patou Judy Urmil
Darius ** Quilmane Kerry Vaianu
Elita Ralph Lola Wati
Frank Sefate Meena Xavier
Gafilo Tom Nancy Yani
Helma Umuri Olaf Zita
Itseng Valetta Percy Arthur
Jubela Wells Rae Becky
Katiba Xivier
Lenny Yvonne
Moingaza Zuri
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for September: 1 tropical depression
1 tropical storm
1 hurricane
2 major hurricanes **
** - one of these did not reach major hurricane status until October
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 September
----------------------------------------
September was an active month in the Atlantic basin. Over the period
1950-2002, the month of September has averaged 3.5 named tropical storms,
2.4 hurricanes, and 1.25 intense (Category 3+) hurricanes. September,
2003, produced 4 named storms, 3 hurricanes, and 1 intense hurricane.
(Kate, which formed in September, did not reach major hurricane status
until October.) Over the 1950-2002 period, September has averaged about
three intense hurricane days. This year, there were 13.5--due to the
long-lived Cape Verde hurricanes Fabian and Isabel.
As the month opened, Fabian was already a major hurricane and
continued to intensify, reaching its peak intensity on 1 September.
On the 5th the large, severe hurricane passed directly over the island
of Bermuda as a Category 3 hurricane on the Saffir/Simpson scale--the
most intense storm to strike the island since 1926. Since Fabian
originated in August, it was covered completely in the August tropical
cyclone summary. Also, on the first couple of days in September, the
remnants of former Tropical Storm Grace were weakening over Texas and
Arkansas.
Tropical Storm Isabel was christened in the eastern Atlantic on
6 September, and subsequently became the first Category 5 hurricane in
the Atlantic basin since Hurricane Mitch in October, 1998. Isabel
reached a peak intensity of 145 kts and maintained intense hurricane
status for 8 days, Category 4 intensity for 6.75 days, and was a
Category 5 hurricane for a total of 2.25 days. Isabel fortunately
weakened as it approached the U. S. East Coast, and was a Category
2 hurricane with 90-kt winds as it made landfall on the Outer Banks of
North Carolina.
Hurricane Juan formed on the 25th east-southeast of Bermuda.
Initially more subtropical in nature, Juan soon acquired tropical storm
characteristics and reached hurricane intensity the next day. Juan
pursued a basic northward trajectory which carried the hurricane inland
near Halifax, Nova Scotia, on the 29th as a Category 2 hurricane. The
storm was reported to have been the most destructive hurricane to strike
the city of Halifax in well over a century. Tropical Storm Kate formed
during the final week of September in the eastern Atlantic, briefly
reached hurricane intensity early on the 30th, and then weakened back
to tropical storm status. Kate regained hurricane intensity late on
1 October, and on the 3rd became the season's third major hurricane.
The only other tropical cyclone to form during September was Tropical
Depression 14. This system formed southeast of the Cape Verde Islands
and later moved northwestward, passing near or over the westernmost
Cape Verdes as it weakened. The official TPC/NHC storm report on TD-14,
written by James Franklin, can be found at the following URL:
http://www.nhc.noaa.gov/2003fourteen.shtml?>
Since the TPC/NHC storm reports are now available online, I have not
written detailed preliminary reports as I usually do. Links to the
various cyclone reports can be found in the brief report on each storm.
TROPICAL STORM HENRI
(TC-12)
3 - 13 September
----------------------------------------
Tropical Storm Henri was a short-lived cyclone which formed in the
eastern Gulf of Mexico in early September from a tropical wave which
had left the coast of Africa several days earlier. Henri reached an
estimated peak intensity of 50 kts on 5 September, then weakened very
quickly to tropical depression status and crossed the Florida Peninsula,
moving eastward into the Atlantic. The depression never regained
tropical storm intensity in the Atlantic and soon became extratropical.
The official storm report on Henri, authored by Daniel Brown and
Miles Lawrence, is available online at the following URL:
http://www.nhc.noaa.gov/2003henri.shtml?>
The peak Best Track intensity of 50 kts represents an upgrade from the
peak operational intensity of 45 kts. The Best Track file is contained
in the storm report referenced above. The operational track, including
the extratropical gale stage, can be found in the tropical cyclone tracks
file for September prepared by the author.
HURRICANE ISABEL
(TC-13)
6 - 22 September
------------------------------------
Hurricane Isabel was one of the truly great Atlantic hurricanes of
the past century. Based on the operational MSW estimates, Isabel was
a hurricane for 11.5 days and an intense hurricane for 8.0 days. Even
more significantly, the great storm was at Saffir/Simpson Category 5
intensity for 2.25 days, making it the third longest-lived Category 5
hurricane since the beginning of the reconnaissance era in 1944. The
hurricane also maintained 130-kt winds (equivalent to a Western Pacific
super typhoon) for four full days. Another significant feature of Isabel
was that it reached Category 5 intensity further east (45.9W) than any
other known Category 5 storm. The previous easternmost Catetory 5
development was Hurricane Cleo in 1958 (49.8W), but it is very question-
able whether Cleo was truly a Category 5 hurricane. The only other
hurricanes to reach Category 5 intensity east of 60W, based on the
current Best Track file, were Donna in 1960 (58.0W) and Hugo in 1989
(54.6W). (NOTE: The other Atlantic hurricanes maintaining Category 5
intensity longer than Isabel were Dog in 1950 (2.5 days) and Allen in
1980 (3.0 days)).
Very, very fortunately for the U. S. East Coast, Isabel had weakened
into a 90-kt Category 2 hurricane by the time it made landfall on North
Carolina's Outer Banks on 18 September. The storm was still deadly and
destructive, however. At least 16 fatalities were directly attributed
to Isabel, mostly from drowning. There were some more deaths indirectly
related to the hurricane. The storm pushed water levels in the upper
Chesapeake Bay to record levels. Levels in Washington DC, Annapolis and
Baltimore exceeded the previous record levels established in the 1933
Chesapeake-Potomac hurricane. Delaware Bay and the Delaware River also
experienced a significant storm surge. The total damage caused by
Isabel in the U. S. is currently estimated at $3.37 billion.
Isabel was able to generate the so-called "annular" hurricane struc-
ture around the time it reached its maximum intensity. Annular hurri-
canes generally display a large eye surrounded by a solid ring of
intense convection, with little convection elsewhere. Such storms are
usually not prone to the ups and downs in intensity related to the
eyewall replacement cycles commonly seen in intense tropical cyclones.
One very interesting feature of Isabel was the formation of mesovortices
in the eyewall. These were very striking in satellite imagery, at one
point being arranged in a pentagonal "starfish" pattern.
Tropical Storm Isabel was named on the morning of 6 September in the
far eastern Atlantic, being upgraded directly from a tropical wave.
Hurricane intensity was reached on 7 September, and by 1200 UTC on the
8th Isabel had become the season's second intense hurricane. Category 5
intensity was initially reached at 1800 UTC on the 11th and maintained
through 1200 UTC on the 14th (except for a 12-hour period on the 13th).
The peak operational MSW was estimated at 140 kts, but this was nudged
upward 5 kts during post-storm analysis. Isabel was still a tropical
storm when it made its final landfall in Canada (after crossing Lake
Erie). According to data sent by Chris Fogarty of the Canadian
Hurricane Centre, at least two stations on the north shore of Lake Erie
(Port Colborne and Long Point) recorded sustained winds exceeding gale
force. Chris' report on Isabel can be accessed at the following link:
http://www.novaweather.net/Isabel_Data/Storm_Summary.pdf>
The official NHC report for "super" Hurricane Isabel, authored by
Jack Beven, is now available at the following URL:
http://www.nhc.noaa.gov/2003isabel.shtml?>
HURRICANE JUAN
(TC-15)
25 - 30 September
-------------------------------------
Hurricane Juan formed out of the complex interaction between a
tropical wave, an upper-level LOW, and a frontal zone. The first
advisory on Tropical Depression 15 was issued at 1500 UTC on
25 September, and the system was upgraded to Tropical Storm Juan six
hours later. However, a careful analysis of all the available data
suggests that a depression had formed on 24 September. Juan moved on
a generally north-northwest to northerly track from its genesis south-
east of Bermuda and made landfall near Halifax, Nova Scotia, as a
Category 2 hurricane on the Saffir/Simpson scale.
The last time Halifax was struck by the eyewall of a hurricane was
on 21 August 1893. Juan was the most damaging hurricane to strike Nova
Scotia in modern times. According to a report on the website of the
Canadian Hurricane Centre, Juan claimed eight lives, either directly or
indirectly. (The NHC report indicates two direct fatalities with three
indirect.) Thousands of trees were blown down, and there were many
downed power lines as well as considerable structural damage. Juan also
crossed Prince Edward Island as a tropical storm. The Canadian news
media reported that the total estimated damage from Juan was around
$200 million (Canadian dollars).
The official TPC/NHC storm report on Juan, authored by Lixion Avila,
is available at the following URL:
http://www.nhc.noaa.gov/2003juan.shtml?>
The Canadian Hurricane Centre has a page dedicated to coverage of
Hurricane Juan at the following link:
http://www.atl.ec.gc.ca/weather/hurricane/juan/>
Also, Chris Fogarty has put together a page of many Juan-related
articles as well as pictures of storm damage:
http://www.novaweather.net/Hurricane_Juan.html>
HURRICANE KATE
(TC-16)
25 September - 9 October
--------------------------------------------
Tropical Depression 16 formed on 25 September roughly 800 nm west-
southwest of the Cape Verde Islands. Moving northwestward for the next
couple of days, the system was upgraded to Tropical Storm Kate on the
27th. Kate proved to be stubborn, and despite south-southwesterly
vertical shear, strengthened during the following two days, briefly
attaining hurricane status on 29 September. A temporary weakening
trend set in as Kate, moving on a northeasterly track, turned abruptly
west-southwestward. The storm re-intensified and became a hurricane
once more on 1 October, and became the season's third intense hurricane
on the 3rd when winds reached 100 kts. Kate's west-southwesterly
heading veered gradually more westward and the storm reached its peak
estimated intensity of 110 kts on 4 October when located approximately
565 nm east-southeast of Bermuda.
Kate began to slowly weaken after reaching its maximum intensity.
Furthermore, it had turned northward by 6 October, then began to
accelerate north-northeastward as the MSW fell below hurricane strength.
The system became extratropical on 8 October but remained a powerful
storm as it crossed the North Atlantic, passing south of Iceland on the
9th and north of the UK the next day. The tail end of Hurricane Kate
brought gales to much of northern Scotland with gusts reaching 60 kts.
The official TPC/NHC storm report on Hurricane Kate, written jointly
by Richard Pasch and Robert Molleda, is now available online at the
following URL:
http://www.nhc.noaa.gov/2003kate.shtml?>
(This brief report written by Kevin Boyle)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for September: 1 tropical storm
2 hurricanes
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 (or the
Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii, for
locations west of longitude 140W): 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.
Northeast Pacific Tropical Activity for September
-------------------------------------------------
September was a month of near-normal activity in the Northeast Pacific
basin. Over the 1971-2002 period, the averages for the month are 3.5
named storms, 2.2 hurricanes, and 1.1 intense hurricanes. September of
2003 produced 3 named storms, 2 hurricanes, but no intense hurricane.
Hurricane Marty, however, became a Category 2 hurricane shortly before
striking the southern tip of Mexico's Baja California Peninsula. As the
month opened, Hurricane Jimena was beginning to weaken as it passed to
the south of Hawaii's Big Island. The storm continued to weaken as it
moved west-southwestward across the Central North Pacific, crossing the
International Dateline into the Western North Pacific just before
dissipating. Other than Marty, the other named storms forming in
September were Tropical Storm Kevin and Hurricane Linda. Kevin was just
a minimal tropical storm for only six hours while Linda reached minimal
hurricane strength for 12 hours before quickly weakening.
There was one additional system which warrants mentioning. A tropical
disturbance developed around 1000 nm west-southwest of the tip of Baja
California on 4 September. The area of low pressure remained stationary
for about 24 hours, then began a slow northward drift. On the 5th
convection increased somewhat around the center, prompting SAB to assign
a Dvorak rating of T2.5/2.5. Concurrent Tropical Weather Outlooks from
TPC/NHC indicated that a tropical depression could be forming. However,
early on 6 September convection began to diminish and the T-numbers from
SAB began to quickly come down. (This system was being rated during the
period 4-7 September, and the NRL temporary number was 91E.)
Reports for the cyclones are already available on TPC/NHC's website,
so I have not written the usual detailed preliminary reports for these
storms, but only a brief synopsis of each which will include the link
to the individual storm reports. In the case of Tropical Storm Kevin,
however, Kevin Boyle submitted a short report on his namesake shortly
after the cyclone's brief life, so I have included that below.
TROPICAL STORM KEVIN
(TC-11E)
3 - 6 September
----------------------------------------
This short-lived wimpy tropical storm formed from a disturbance that
moved westward off the coast of Mexico near Manzanillo. This was being
noted in East Pacific STWOs issued by NHC on 31 August. The system
moved generally west-northwestward for a couple of days and was expected
to only slowly strengthen and organise. Even when the first warning was
issued at 1500 UTC on 3 September the disturbance did not look very
impressive, and satellite classifications at this time were T1.0 at the
most. The initial position of the LLCC was located near 19.2N, 111.9W,
and this was only a rough estimate due to the difficulty in pinpointing
the centre. The depression was located in an area of modest north-
easterly shear, and slow strengthening was forecast to continue until
the system reached cooler SSTs in two to three days time. Factors
justifying issuance of the first warning were: a southerly wind and a
1001.6 mb pressure reported from Socorro Island at 03/1200 UTC, deep
convection becoming more concentrated near Socorro as evidenced from
satellite imagery, and data from a QuikScat pass at 0100 UTC. At the
time of the first advisory the depression was centred roughly 250 nm
south-southwest of Cabo San Lucas.
Tropical Depression Eleven-E continued to move west-northwestward,
along with the monsoon flow, with a MSW of 30 kts. The storm possessed
a large circulation which was elongated northwest-southeast with
abundant convection in a curved band southwest of the centre. The LLCC
remained difficult to locate and three satellite fixes were east of the
previous position at 04/0300 UTC near a burst of convection. Further
relocation at 04/1500 UTC (to 21.2N, 114.3W) was based on
satellite and microwave imagery from a 1200 UTC TRMM pass. The
depression, still over SSTs of 28-29 C, had a slim chance of making the
grade as a tropical storm before moving into increasingly colder waters.
It did so at 04/2100 UTC but for six hours only (warning #6) and unduly
peaked at 35 kts. QuikScat data at 04/1335 UTC found a large area of
30 kt winds surrounding the nucleus of the cyclone with rain contaminated
winds as high as 55 kts in the southwestern quadrant. The core of Kevin
was composed of multiple swirls of clouds rotating around it, and this
made life difficult for the satellite analysts and NHC in determining
where the actual centre was. It was decided to locate the position of
the broad circulation as a whole to overcome this problem. At the time
of its upgrade to tropical storm status, Kevin was located approximately
300 nm west-southwest of Cabo San Lucas.
At 0300 UTC on 5 September Kevin was downgraded to a tropical depres-
sion, the east-northeasterly wind shear exposing the LLCC as the tropical
cyclone began to make its way towards cooler waters. Enhanced infrared
satellite imagery and a 0436 UTC TRMM pass located the LLCC displaced
90 nm from the deep convection, and by the end of the day there was no
associated thunderstorm activity. On the final forecast/advisory at
06/0300 UTC, Kevin was just basically a large swirl of low-level clouds
located roughly 475 nm west of Cabo San Lucas. The remnants of the
depression persisted for several days, eventually drifting northward,
then east-northeastward, and finally to the east-southeast.
There have been no reports of damage or casualties resulting from
the ephemeral Tropical Storm Kevin.
(Report written by Kevin Boyle)
NOTE: The official NHC storm report on Tropical Storm Kevin, written
by Stacy Stewart, is now available online at the following link:
http://www.nhc.noaa.gov/2003kevin.shtml?>
HURRICANE LINDA
(TC-12E)
14 - 17 September
-------------------------------------
Tropical Depression 12E formed on 14 September about 300 nm west-
southwest of Manzanillo, Mexico. Six hours later the depression was
upgraded to Tropical Storm Linda. Linda moved northwestward and
intensified steadily, reaching hurricane intensity around 1800 UTC when
centered approximately 265 nm southwest of Cabo San Lucas on the tip of
the Baja California Peninsula. Linda did not intensify beyond 65 kts,
and was downgraded back to a tropical storm only 12 hours after being
upgraded to hurricane status. Linda's track turned toward the west
and the storm steadily weakened, the last advisory being issued at
2100 UTC on 17 September.
The official storm report on Hurricane Linda, written by Jack Beven,
is now available online at the following link:
http://www.nhc.noaa.gov/2003linda.shtml?>
HURRICANE MARTY
(TC-13E)
19 - 25 September
-------------------------------------
Hurricane Marty became the second hurricane in less than a month to
affect the Baja California Peninsula. Whereas Ignacio in late August
had moved to the east of Cabo San Lucas, eventually making landfall
north of La Paz and dissipating over the southern portion of the
peninsula, Marty moved directly over the Cabo as a Category 2 hurricane
and moved up the entire eastern shore of Baja California, reaching the
upper reaches of the Gulf of California as a tropical storm. The system
then weakened to a depression and meandered about the northern Gulf for
a couple of days before dissipating.
The Mexican government reported that Marty was responsible for twelve
deaths in the country. Five lives were lost when a fishing vessel sank
while the remainder of the fatalities were due to flash flooding along
rivers over the southern peninsula. Some articles about the effects
of Marty can be found at the following URL:
http://www.reliefweb.int/w/rwb.nsf/vLND>
The official NHC storm report on Hurricane Marty, written by James
Franklin, is available online at the following link:
http://www.nhc.noaa.gov/2003marty.shtml?>
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for September: 3 tropical depressions **
2 typhoons
1 super typhoon
** - None of these were classified as tropical depressions by JTWC. One
of these was named by PAGASA and treated as a tropical depression
by some of the other Asian TCWCs; two others were classified as
tropical depressions by JMA only.
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Michael V. Padua of Naga City in the Philippines, owner of the
Typhoon 2000 website, normally sends me cyclone tracks based upon
warnings issued by the Japanese Meteorological Agency (JMA) and the
Philippines' Atmospheric, Geophysical & Astronomical Services
Administration (PAGASA). Also, Huang Chunliang of Fuzhou City, China,
sends me each month tracks obtained from warnings issued by the
National Meteorological Center of China (NMCC), the Central Weather
Bureau of Taiwan (CWBT) and the Hong Kong Observatory (HKO). A very
special thanks to Michael and Chunliang for the assistance they so
reliably provide.
In the title line for each storm I have referenced all the cyclone
names/numbers I have available: JTWC's depression number, the
JMA-assigned name (if any), JMA's tropical storm numeric designator,
and PAGASA's name for systems forming in or passing through their
area of warning responsibility.
Northwest Pacific Tropical Activity for September
-------------------------------------------------
As the month of September opened, intense Typhoon Dujuan was passing
just south of the southern tip of Taiwan. A couple of days later a
somewhat weaker typhoon made landfall in southeastern China near Hong
Kong. The complete report on Typhoon Dujuan was included in the August
tropical cyclone summary. Three typhoons came to life during September
with Super Typhoon Maemi by far the most significant. The intense storm
peaked at 150 kts on the 10th, and although somewhat weaker by the time
it landed in South Korea, Maemi still caused much destruction and loss
of life in that nation. The other September typhoons, Choi-wan and
Koppu, both were typhoons of moderate intensity which pursued generally
northeasterly tracks that carried them southeast of Japan into the
open North Pacific.
In addition to the typhoons, three other systems were classified as
tropical depressions by one or more of the Asian TCWCs, although not by
JTWC. The first of these was tracked as a tropical depression by JMA
only on the 2nd and 3rd as it moved generally northward several hundred
miles east of the Northern Marianas. JTWC had assigned this area a
fair development potential on 31 August, but downgraded it to poor on
1 September.
Another system which only JMA referenced as a tropical depression
formed on 12 September at a fairly high latitude about 200 nm southeast
of Tokyo. JTWC initially assigned this system a fair potential for
development, but no TCFA was issued. The system consisted of a well-
defined fully-exposed LLCC with associated convection displaced to the
southeast. Shear was relatively weak, but there was very little
divergence over the area. (No track was given for this system in the
companion cyclone tracks file.)
The third tropical depression was named Quiel by PAGASA. This system,
as tracked by PAGASA, formed well to the east of the Philippines and
eventually tracked into the northern South China Sea. However, there was
a "jump" of four degrees of longitude on 17 September. This was another
confusing "monsoon mess" situation similar to that which had occurred in
August with Tropical Depression Lakay and Tropical Storm Vamco. A second
circulation arose in the general region which PAGASA dubbed Roskas and
which subsequently became Typhoon Choi-wan. More details on Quiel can
be found in the September tropical cyclone tracks file.
The reports on Typhoons Maemi, Choi-wan and Koppu were written by
Kevin Boyle and with significant contributions by Huang Chunliang. A
special thanks to these gentlemen for their assistance. Also included
below is a report sent by Huang Chunliang concerning rainfall associated
with a South China Sea system, probably a monsoon depression, in mid-
September.
SUPER TYPHOON MAEMI
(TC-15W / 0314 / POGI)
3 - 15 September
------------------------------------------
Maemi: contributed by DPR (North) Korea is the cicada, a type of insect
which chirps during the summer months when typhoons threaten
Korea
Pogi: PAGASA name, means 'handsome'
A. Storm Origins
----------------
Super Typhoon Maemi's explosive career began when an area of
convection formed approximately 160 nm southeast of Yap (7.6N, 140.3E).
This suspect area was noted in JTWC's STWO issued at 0600 UTC on
2 September, having persisted for the previous 12 hours. At this time
microwave imagery, combined with a QuikScat pass, indicated a broad
surface trough while animated multi-spectral satellite pictures revealed
cycling and disorganised convection. Upper-air analyses showed both
diffluence and shearing conditions to be moderate. The potential for
the disturbance's development during the next 24 hours was assessed as
poor. This was upgraded to fair status at 04/1300 UTC when convection
was seen to become better organised in enhanced satellite animations,
and a 04/0731 UTC QuikScat pass revealed a weak, broad and elongated
LLCC. Guam was reporting light winds from the northwest and surface
pressures of 1009 mb; the centre of the disturbance was located
approximately 310 nm to the southeast. Shearing conditions were clearly
evident in animated satellite images, and 200-mb charts from the
University of Wisconsin CIMSS were showing 20-30 kts of northeasterly
shear over the system. Despite this, JTWC issued a TCFA at 05/0200 UTC
after a 04/2211 UTC SSM/I pass depicted deep convective bands in the
southern quadrants wrapping into the LLCC.
Warnings were initiated at 05/1800 UTC on Tropical Depression 15W,
located approximately 65 nm west-northwest of Guam. At that time a
marked increase in deep convection was noted over the LLCC in enhanced
infrared satellite imagery. TD-15W intensified at a climatological rate
as it moved west-northwestward at 15 kts under the steering influence of
a low to mid-level ridge north-northeast of the system. The depression
was upgraded to a 40-kt tropical storm on the second warning, issued at
06/0000 UTC, based on a 40-kt QuikScat observation and CI estimates of
30 kts and 45 kts. The Prognostic Reasoning message issued by JTWC at
this time called for TS-15W to continue moving west-northwestward through
96 hours. After 96 hours a deep trough over eastern China was expected
to weaken the mid-level ridge over western China, causing the tropical
cyclone to change to a north-northwesterly heading. In the meantime,
the storm was predicted to intensify due to favourable outflow and shear
conditions.
B. Track and Intensity History
------------------------------
Tropical Storm 15W continued moving west-northwestward at 13 kts,
arriving at a position approximately 230 nm west-northwest of Guam by
0600 UTC on 6 September. At this time JMA upgraded the system to
tropical storm intensity and assigned the name Maemi. Upper-level
analysis charts indicated that the environment remained conducive to
further strengthening, and the MSW increased by five knots on the next
two warnings, issued at 1200 UTC and 1800 UTC, to 45 kts and 50 kts,
respectively. During this period the storm tracked northwestward
before reverting back to its original west-northwesterly heading at
07/0000 UTC, by which time the maximum intensity had risen to 60 kts.
Maemi became a typhoon at 07/1200 UTC when located approximately 650 nm
southeast of Okinawa, Japan. Only a 5-kt increase in the MSW was noted
during the 8th, and despite the system's becoming further organised
(with an eye beginning to form at 1800 UTC as seen in enhanced infrared
imagery), the overall intensity remained steady at 75 kts until the 9th.
Then Maemi got down to some serious intensification. PAGASA had little
cause for concern, except for enhancement of the southwest monsoon, as
it was clear by this time that Typhoon Pogi (their internal name) was
curving away from the Philippines.
In fact, by 0000 UTC on 9 September Typhoon Maemi/Pogi had turned to a
northwesterly heading. The 16-nm irregular eye, as depicted in a SSM/I
pass at 08/2253 UTC, was centred approximately 305 nm south-southeast of
Okinawa. Rapid strengthening had already begun with the MSW jumping
from 75 kts to 90 kts. The MSW took a bigger jump to 115 kts at 09/0600
UTC, and by 09/1200 UTC Maemi was a super typhoon with a MSW of 130 kts.
JTWC's wind distribution on the 1200 UTC warning (#16) indicated that
Maemi was a fairly small cyclone with 100-kt winds extending 20 nm from
the centre and a gale radius of 130 nm. Super Typhoon Maemi was expected
to be influenced by the mid-level ridge to the north-northeast for at
least another 24 hours or so before turning poleward into a weakness
induced by a shortwave trough over China. This trough was expected to
engage Maemi and turn the storm northeastward between Korea and Japan.
At 0000 UTC on 10 September Super Typhoon Maemi was approaching the
southern part of the Ryukyu Island chain and passing approximately 180 nm
south of Okinawa, Japan, moving on a northwesterly heading at a slower
pace of 5 kts. However, Maemi was not to make its closest point of
approach to Okinawa for another 36 hours. Animated water vapour imagery
showed that outflow from the northwest quadrant had merged into the
upper-level southwesterly flow ahead of the major shortwave trough over
eastern China. This had the effect of whisking away the cyclone's
exhaust, and by 10/0000 UTC the MSW had reached monumental proportions.
Based on CI estimates of 127, 140 and 155 kts, the MSW reached a peak of
150 kts, gusting to 180 kts. Unfortunately, Miyakojima lay in the path
of the super typhoon and the island had to endure extreme conditions
while the eye passed by just to the northeast at 10/1800 UTC. The lowest
pressure recorded on Miyakojima was 912.0 mb at 1912 UTC. The intensity
began to fall at this point to 135 kts--no consolation to Miyakojima,
however.
Editor's Note: The peak 10-min avg MSW estimates from JMA and NMCC
were 105 kts and 120 kts, respectively. PAGASA was estimating the
intensity of Typhoon Pogi/Maemi at 100 kts at the time the storm moved
out of that agency's AOR at 10/1200 UTC.
Super Typhoon Maemi was turning poleward at 0000 UTC on 11 September
as the steering flow influencing the typhoon changed. This allowed the
storm to creep a little bit closer to Okinawa, Japan, and the eye passed
approximately 130 nm west-northwest of Okinawa. At this juncture Maemi
began to accelerate as it moved northward into the East China Sea, the
MSW holding steady at 135 kts (although it had dipped briefly to 130 kts
at 11/0000 UTC). A definite weakening trend set in at 11/1800 UTC when
Maemi lost its super typhoon title and the MSW dropped to 120 kts. This
was the result of increasingly hostile environmental conditions caused
by the deepening trough encroaching from the west.
The next day at 12/0000 UTC Maemi was located approximately 160 nm
south of Cheju Island, moving smartly toward the north-northeast at
23 kts towards the Korean Peninsula. The MSW was still estimated at 120
kts, but convection on the western side had weakened. At 12/0600 UTC
Maemi was nearing Cheju Island with winds still near 100 kts. Six
hours later the typhoon was located approximately 30 nm southwest of
Pusan and was poised to skirt the southeastern coast of South Korea.
Weakening continued, albeit slowly at first, but the Korean Peninsula
took a significant amount of strength away and Maemi crossed South Korea
as an 80 to 90-kt system. By 12/1800 UTC Typhoon Maemi was undergoing
transition to a extratropical system as it pushed northeastward at 24
kts over the Sea of Japan. This extratropical conversion was more or
less complete six hours later and the MSW fell below typhoon intensity.
The circulation of the once-powerful Maemi began to fall apart, and
multi-spectral satellite imagery indicated that the mid-level circulation
centre had sheared 100 nm to the north-northeast of the LLCC. The final
warning from JTWC was issued at 13/0000 UTC; the last position was 40.5N,
134.8E, or approximately 300 nm west of Misawa, Japan. JMA declared
Maemi extratropical at 14/0000 UTC and tracked the remnants north-
northeastward to a position east of the Kamchatka Peninsula where the
system had weakened to a 45-kt gale by the 15th.
C. Meteorological Observations from China
-----------------------------------------
All the observations in this section were obtained from a report sent
by Huang Chunliang of Fuzhou City, Fujian Province, China. A special
thanks to Chunliang for compiling and sending the information.
(1) Rainfall Observations from Taiwan (WMO stations)
----------------------------------------------------
City/County Station Period Rainfall
(WMO ID) (UTC) (mm)
--------------------------------------------------------------------
Ilan City, Ilan 46708 09/1600-10/1600 122.0
Chu-tzu-hu, Taipei City 46693 09/1600-10/1600 120.5
Taipei, Taipei City 46692/58968 09/1600-10/1600 114.0
(2) Rainfall Observations from Taiwan (Automatic weather stations)
------------------------------------------------------------------
City/County Station Period Rainfall
(CWB ID) (UTC) (mm)
--------------------------------------------------------------------
Ilan County C1U61 09/1600-10/1600 227.5
Ilan County C1U52 09/1600-10/1600 201.5
Ilan County C1U63 09/1600-10/1600 186.0
Ilan County C1U51 09/1600-10/1600 167.5
Ilan County C1U67 09/1600-10/1600 167.0
Ilan County C1U66 09/1600-10/1600 160.0
Ilan County C1U62 09/1600-10/1600 123.5
Ilan County C0U60 09/1600-10/1600 123.0
Ilan County C1U69 09/1600-10/1600 122.5
Ilan County C1U59 09/1600-10/1600 111.0
Ilan County C0U64 09/1600-10/1600 108.0
Ilan County C1U50 09/1600-10/1600 106.5
Taipei County L1A81 09/1600-10/1600 220.0
Taipei County L1A83 09/1600-10/1600 163.0
Taipei County 01A17 09/1600-10/1600 160.0
Taipei County C0A53 09/1600-10/1600 158.0
Taipei County L1A82 09/1600-10/1600 146.5
Taipei County L1A80 09/1600-10/1600 144.0
Taipei County C0A57 09/1600-10/1600 142.5
Taipei County A0A9M 09/1600-10/1600 135.5
Taipei County 01A21 09/1600-10/1600 132.0
Taipei County C0A54 09/1600-10/1600 131.0
Taipei County L1A79 09/1600-10/1600 130.5
Taipei County 01A44 09/1600-10/1600 130.0
Taipei County C0A55 09/1600-10/1600 126.0
Taipei County C1A9N 09/1600-10/1600 125.5
Taipei County C0A51 09/1600-10/1600 125.5
Taipei County C0A58 09/1600-10/1600 125.5
Taipei County C1A65 09/1600-10/1600 124.5
Taipei County C0A9D 09/1600-10/1600 115.0
Taipei County C1A64 09/1600-10/1600 112.0
Taipei County L1A84 09/1600-10/1600 111.0
Taipei County C1A70 09/1600-10/1600 105.0
Taipei City C1A69 09/1600-10/1600 143.5
Taipei City 01A42 09/1600-10/1600 115.0
Taipei City 01A43 09/1600-10/1600 115.0
Taipei City C0A9H 09/1600-10/1600 112.0
Taipei City C1A73 09/1600-10/1600 109.5
Taipei City C0A9C 09/1600-10/1600 107.0
Hsinchu County C0D36 09/1600-10/1600 146.5
Hsinchu County C1D40 09/1600-10/1600 122.5
Hsinchu County C1D39 09/1600-10/1600 115.5
Hsinchu County C1D42 09/1600-10/1600 113.0
Hsinchu County 21D15 10/1600-11/1600 100.0
Yunlin County C0K24 09/1600-10/1600 141.5
Miaoli County C0E41 09/1600-10/1600 124.0
Miaoli County C1E47 09/1600-10/1600 102.5
Taoyuan County 01C40 09/1600-10/1600 106.0
Taoyuan County A0C54 09/1600-10/1600 103.5
Taoyuan County 21C08 09/1600-10/1600 101.0
Chia-I County C1M62 09/1600-10/1600 103.5
D. Meteorological Observations from Japan
-----------------------------------------
The information in this section was also sent by Huang Chunliang.
(1) Peak Wind Observations (from Okinawa)
-----------------------------------------
Station Station Lat Lon Alt MSW Time Gust Time
Name (WMO ID) (m) (kts) (UTC) (kts) (UTC)
---------------------------------------------------------------------
Naha 47936 26.2N 127.7E 28 37 10/1020 63 11/1012
Kumejima 47929 26.3N 126.8E 4 35 11/0740 71 11/0825
Miyakojima 47927 24.8N 125.3E 40 75 10/1800 144 10/1812
Ishigakijima 47918 24.3N 124.2E 6 42 10/1750 78 10/2006
Iriomotejima 47917 24.4N 123.8E 9 36 11/0210 61 10/0041
Irabu 93011* 24.8N 125.2E 10 82 10/1950
* - JMA station code
Note: Only stations that reported sustained winds (10-min avg) greater
than gale force or gusts greater than typhoon force are included above.
(2) More gust reports (from Okinawa & Nagasaki)
-----------------------------------------------
Station WMO Lat Lon Alt Gust Time
Name ID (m) (kts) UTC
------------------------------------------------------------------
Miyakojima, Okinawa 47927 24.8N 125.3E 40 85 10/1330
Miyakojima, Okinawa 47927 24.8N 125.3E 40 91 10/1510
Miyakojima, Okinawa 47927 24.8N 125.3E 40 107 10/1550
Miyakojima, Okinawa 47927 24.8N 125.3E 40 117 10/1700
Miyakojima, Okinawa 47927 24.8N 125.3E 40 143 10/1740
Nago, Okinawa 47940 26.6N 128.0E 6 59 11/1500
Sasebo, Nagasaki 47812 33.2N 129.7E 4 59 12/0711
Hirado, Nagasaki 47805 33.4N 129.6E 58 61 12/0820
Izuhara, Nagasaki 47800 34.2N 129.3E 4 79 12/1020
Izuhara, Nagasaki 47800 34.2N 129.3E 4 90 12/1136
Note: Above are those which were highlighted in the JMA local warnings
and could not be regarded as the peak values.
(3) Records (from Miyakojima, Okinawa)
--------------------------------------
(a) As was noted in Part 1, the station reported a peak gust of 144
kts at 10/1812 UTC, which turned out to be the fourth highest daily
peak that had ever been recorded in Okinawa, or the seventh highest
daily peak that had ever been recorded in Japan (see Section d for
the Top Ten).
(b) The station reported a minimum pressure of 912.0 hPa (sea level) at
10/1912 UTC, which turned out to be the second lowest daily value that
had ever been recorded in Okinawa, or the fourth lowest daily value
that had ever been recorded in Japan (see Section e for the Top Ten).
(c) Rains of 58.5 mm recorded from 10/2021 UTC through 10/2121 UTC
represent the peak hourly value for the station during the passage
of Maemi. Rains of 402.5 mm recorded from 10/0800 UTC through
11/0800 UTC broke the former record 24-hour total ever recorded in
September by the station. A storm total of 465 mm was recorded from
08/1500 UTC through 12/0600 UTC.
(d) The Top Ten typhoons that brought the highest daily peak gusts to
Japan have been listed below:
Rank JMA Storm Pk Gust Station Date
TY # Name (kts) Name (JST)
------------------------------------------------------------------
01* 6618 Cora 166 Miyakojima, Okinawa Sep 05, 1966
02 6118 Nancy 164 Murotomisaki, Kochi Sep 16, 1961
03 6816 Della 155 Miyakojima, Okinawa Sep 22, 1968
04 7009 Wilda 153 Naze, Kagoshima Aug 13, 1970
05 6816 Della 152 Miyakojima, Okinawa Sep 23, 1968
06 6523 Shirley 150 Murotomisaki, Kochi Sep 10, 1965
07 0314 Maemi 144 Miyakojima, Okinawa Sep 11, 2003
08 5612 Emma 143 Naha, Okinawa Sep 08, 1956
09 6420 Wilda 141 Uwajima, Ehime Sep 25, 1964
10 9413 Doug 136 Yonagunijima, Okinawa Aug 07, 1994
10 7705 Vera 136 Ishigakijima, Okinawa Jul 31, 1977
Note (*): It should be noted that the station located on top of
Mt. Fuji recorded a peak SSW gust of 177 kts associated with TY 6626
(Typhoon Ida) on 25 September 1966. But it was not included in the
roster above since it was reported by a mountain station.
(e) The Top Ten typhoons that brought the lowest daily minimum
pressures (sea level) to Japan have been listed:
Rank JMA Storm Min Press Station Date
TY # Name (hPa) Name (JST)
------------------------------------------------------------------
01 7709 Babe 907.3 Okinoerabu, Kagoshima Sep 09, 1977
02 5914 Sarah 908.1 Miyakojima, Okinawa Sep 15, 1959
03 ---- ---- 911.6 Murotomisaki, Kochi Sep 21, 1934
04 0314 Maemi 912.0 Miyakojima, Okinawa Sep 11, 2003
05 ---- Ida 916.1 Makurazaki, Kagoshima Sep 17, 1945
06 6118 Nancy 918.0 Naze, Kagoshima Sep 15, 1961
07 ---- Ida 922.6 Kagoshima, Kagoshima Sep 17, 1945
08 6314 Gloria 923.5 Ishigakijima, Okinawa Sep 10, 1963
09 6314 Gloria 926.3 Ishigakijima, Okinawa Sep 11, 1963
10 9609 Herb 927.1 Iriomotejima, Okinawa Jul 31, 1996
(4) Hourly Sustained Wind/Pressure Observations
-----------------------------------------------
1. Station: Miyakojima, Okinawa (WMO 47927)
-------------------------------------------
Latitude: 24.79 N Longitude: 125.28 E Altitude: 40 m
The hourly MSW (10-min avg) exceeded gale force at Miyakojima from
1300 UTC on 10 September through 0500 UTC on the 11th, except for a
two-hour drop off when the station was in the typhoon's eye. The peak
hourly MSW of 75 kts occurred at 10/1800 UTC, shortly before eye passage.
The minimum hourly SLP recorded in the eye was 913.2 hPa at 10/1900 UTC.
2. Station: Irabu, Okinawa (JMA 93011)
--------------------------------------
Latitude: 24.83 N Longitude: 125.17 E Altitude: 10 m
The hourly MSW (10-min avg) exceeded gale force at Irabu from 0900
UTC on 10 September through 0400 UTC on the 11th except for 0100 UTC
on the 11th. The eye of Maemi did not pass over this station. The
maximum hourly MSW of 76 kts occurred at 10/2000 UTC.
(5) Rainfall Observations
-------------------------
Only a report highlighted in one of the JMA local warnings was given
below due to my (Huang Chunliang's) personal time restriction:
10/2000 UTC - 10/2100 UTC Shimojishima, Okinawa 108 mm
Note--Two important sources of this special report should be noted
here:
1. A special report prepared by the local meteorological service of
Okinawa, which is under the control of JMA:
http://www.okinawa-jma.go.jp/news/tifu0314/td0314.pdf>
(Size: 318 Kbytes -- Language: Japanese)
2. Raw data on the offical web pages of JMA (Japanese version):
http://www.jma.go.jp/>
E. Meteorological Observations from Korea
-----------------------------------------
Roger Edson sent along some observations from South Korea taken
on 12 September through 1300 UTC. A special thanks to Roger for
passing along this information.
(1) Rainfall Observations
-------------------------
Below are listed the daily precipitation amounts exceeding 100 mm.
Presumably, these are the rainfall totals from 0000 through 1300 UTC
on the 12th, around the time of landfall near Pusan.
Station Precipitation (mm) Station Precipitation (mm)
---------------------------------------------------------------------
Wando 119.5 Yeosu 214.0
Suncheon 159.0 Jangheung 134.0
Haenam 134.5 Goheung 273.5
Jeju 231.5 Uljin 125.5
Daegu 135.0 Pohang 131.5
Gumi 118.0 Yeongcheon 122.5
Masan 152.0 Tongyeong 139.0
Jinju 250.5 Geochang 146.5
Hapcheon 169.0 Miryang 159.5
Sancheong 221.5 Geoje 116.5
Namhae 401.5
(2) Wind Observations
---------------------
At 12/1215 UTC the Pusan Airport was reporting sustained SSE winds
of 59 kts, gusting to 77 kts. One hour later the same station was
reporting sustained SSW winds of 46 kts, gusting to 62 kts.
A very important wind observation was made on the island of Cheju,
just off the coast of South Korea. Typhoon Maemi's center passed just
east of the island with much of the island in the eye. Seongsanpo,
on the east side of Cheju, recorded the minimum pressure of 955.1 hPa
at 0700 UTC. The station was in the eye with a MSW (10-min avg) of
only around 30 kts. The airport on the north coastline of the island
recorded winds of near typhoon strength at 60 kts. But Gosan on the
western side of Cheju and in the western eyewall recorded a 10-min
mean wind of 93 kts. At 0600 UTC JTWC was estimating the 1-min avg
MSW at 105 kts. A 93-kt 10-min avg wind equates to a 1-min mean
wind of 106 kts--very good agreement. The Gosan observation also was
very close to NMCC's 0600 UTC 10-min avg MSW of 90 kts, but somewhat
higher than JMA's estimate of 80 kts.
F. Damage and Casualties
------------------------
Typhoon Maemi was described as the most powerful storm of the
century as it tore through South Korea, and press reports indicate that
at least 85 people died in that nation. The Korean government deployed
5600 soldiers to help rescue workers search for 25 missing persons and
perform clean-up operations. A total of 25,000 people were forced
from their homes and had to seek shelter in schools and public buildings.
South Korea's largest port of Busan was badly affected by the storm--
eleven container-lifting cranes, each weighing 900 tons each were
toppled and 6 metre-long steel containers were scattered around the
port.
Typhoon Maemi made landfall at high tide, and 282 ships were beached
and wrecked by large waves. At one beach a cruise ship converted into
a floating hotel was flipped over onto its side--fortuitously it had
been evacuated in time. At least 18 empty fishing vessels were capsized.
The world's largest shipbuilder, Hyundai Heavy Industries, reported that
giant waves threw a 200,000-ton offshore storage facility belonging to
Exxon Mobile into a 37,000-ton petrochemicals carrier being built by
Hyundai Mipo Dockyard for a German firm. Both were damaged.
Vast areas of farmland, cities and rivers were flooded as up to 460 mm
of rain fell. Up to 12,626 acres of farmland, including rice paddies
and orchards, were flooded before the harvest, raising concerns that the
price of rice--the country's staple food--might rise significantly.
Widespread flooding also caused chaos on roads. The few cars that did
venture out were buffeted by strong winds as they moved cautiously with
headlights and hazard lights on. Many highway road signs were downed
(some fell on vehicles), traffic signals were damaged, vehicles were
seen floating down streets that were turned into raging torrents, and
many roads were blocked or washed away by landslides. One landslide
derailed an express train travelling from Seoul to Andong, injuring 28
people. Navy divers were called in to search flooded areas for victims,
and soldiers used buckets to scoop water from underground parking lots.
Five of South Korea's nuclear power plants were shut down due to
damage to main current transformers and power lines. Fortunately, no
radiation leakages were reported. About 20 major factories in the
cities of Ulsan and Onsan on the southeast coast, including two major
oil refineries, were forced to temporarily halt operations. Electricity
was cut to 1.4 million households, but power was soon restored to the
majority of these. The power outage partially paralyzed telephone
networks: both fixed-line and cellular networks were affected.
Typhoon Maemi also passed through North Korea, but the extent of
damage there is not known because the government has restricted the
release of information.
Editor's Note: An OCHA report on the ReliefWeb website, dated
22 September 2003, indicated that as of that date the confirmed death
toll from Maemi in South Korea had risen to 117 with 13 still missing.
The total damage estimate from the storm was place at US$4.1 billion.
About 5000 homes were destroyed with an additional 13,000 damaged.
Additional articles can be found at the following URL:
http://www.reliefweb.int/w/rwb.nsf/vLND>
(Report written by Kevin Boyle and Huang Chunliang)
MONSOON DEPRESSION RAINFALL
15 - 16 September
-----------------------------------------------
The following report was prepared in its entirety by Huang
Chunliang of Fuzhou City, Fujian Province, China. A special thanks
to Chunliang for compiling and sending the information.
A. Introduction
---------------
JTWC never mentioned the system in their STWOs, neither did NRL
list it as an invest area; thus, no temporary number was assigned by
NRL. JMA was the only agency that ranked the system as a weak tropical
depression, as follows:
15/0600 UTC: TROPICAL DEPRESSION 1004 HPA AT 20N 110E
15/1200 UTC: TROPICAL DEPRESSION 1004 HPA AT 21N 110E
15/1800 UTC: TROPICAL DEPRESSION 1004 HPA AT 21N 110E
16/0000 UTC: TROPICAL DEPRESSION 1004 HPA AT 21N 109E
Judging by the satellite appearances, the system is probably best
classified as a monsoon depression, in my opinion.
Since the system was treated as a weak tropical depression by JMA,
and since it caused widespread torrential rains in the coastal area of
Guangdong Province and a few stations of the Guangxi Zhuang Autonomous
Region, a brief report is included on this system.
B. Rainfall Observations
------------------------
Provinces/Region Station Period (UTC) Rainfall
---------------- -------------- ------------------ ---------
Guangdong Doumen 14/0000 -- 15/0000 225.3 mm
Guangdong Doumen 15/0000 -- 16/0000 136 mm
Guangdong Shantou 14/0000 -- 15/0000 109.1 mm
Guangdong Shanwei 14/0000 -- 15/0000 146.5 mm
Guangdong Yangjiang 15/0000 -- 16/0000 126.0 mm
Guangdong Zhongshan 14/0000 -- 15/0000 222 mm
Guangdong Zhongshan 15/0000 -- 16/0000 172 mm
Guangdong Zhuhai 15/0000 -- 16/0000 142 mm
Guangdong Boluo 15/0000 -- 16/0000 123 mm
Guangdong Panyu 15/0000 -- 16/0000 123 mm
Guangdong Yangchun 16/0000 -- 17/0000 142.8 mm
Guangxi Lipu 16/0000 -- 17/0000 142.5 mm
Guangxi Jinxiu 16/0000 -- 17/0000 146.2 mm
Note: In Guangdong Province, storm totals (14/0000 -- 17/0000 UTC)
exceeded 250 mm in the cities/counties/districts of Zhongshan, Doumen,
Shunde, Panyu, Zhuhai, Yangchun and Jieyang, with Zhongshan reporting
the highest amount of 420.3 mm.
(Report written by Huang Chunliang)
TYPHOON CHOI-WAN
(TC-16W / 0315 / ROSKAS)
17-24 September
--------------------------------------------
Choi-wan: contributed by Hong Kong, China, means 'colourful cloud';
also the name of a housing estate in Hong Kong
Roskas: PAGASA name, is the name for the screw--a piece of hardware
A. Storm Origins:
-----------------
Typhoon Choi-wan did not take too long to develop out of an area of
deep convection initially located approximately 480 nm south-southeast
of Okinawa at 0130 UTC on 17 September. Indeed, only 16.5 hours elapsed
from JTWC's initial reference in the STWO issued at 17/0130 UTC to the
first warning at 1800 UTC later that same day. Animated multi-spectral
imagery and a 16/2215 UTC microwave pass indicated that the area of deep
convection was located on the northeast edge of a broad trough. Even
though the convection appeared rather disorganised, it was under an area
of weak vertical wind shear and favourable diffluence aloft, so the
potential for development at this stage was assessed as fair. This was
upgraded to good and a TCFA released when the LLCC was seen to
consolidate and organise in both animated enhanced infrared pictures and
microwave imagery. The first warning followed at 17/1800 UTC on
Tropical Depression 16W, located approximately 250 nm south-southeast of
Okinawa, Japan. Initial movement was toward the northwest at 8 kts.
B. Storm History
----------------
PAGASA had already assigned their internal name Roskas by the time
of the first JTWC warning, and following JMA's upgrade to a tropical
storm (40 kt, 10-min avg) at 0000 UTC on 18 September, the depression
was christened Choi-wan from the international naming list. Six hours
later TD-16W (Choi-wan) was relocated westward to a position approxi-
mately 285 nm south of Naha, Okinawa, based on the latest multi-spectral
imagery and a 18/0130 UTC SSM/I pass, both which suggested two possible
LLCCs associated with the system. The Prognostic Reasoning Message for
the system issued at 18/1200 UTC indicated a poleward heading as the
developing system moved into southwesterly flow associated with an east-
ward moving shortwave trough, located at the time over the Korean
Peninsula. TD-16W continued to consolidate and intensify. An 18/1121
UTC SSM/I pass in combination with satellite animations indicated the
formation of a deep convective band in the eastern semicircle. Based on
satellite CI estimates of 35 kts and 45 kts, JTWC finally upgraded
Choi-wan to tropical storm intensity with a MSW of 45 kts at 18/1800
UTC. For the past several hours Choi-wan had been moving northward at
8 kts.
By 19/0000 UTC Choi-wan was closing in on Okinawa. The northerly
heading had brought the system to a position approximately 75 nm south
of Naha. The MSW had increased to 55 kts and Choi-wan strengthened to
typhoon intensity while crossing Okinawa around 19/1200 UTC. The storm
veered north-northeastward, crossing the ridge axis, but strengthening
was forecast for the next 24 to 36 hours before Choi-wan would enter the
unfavourable westerly wind flow.
The intensity of Choi-wan remained constant with the MSW only slowly
rising to 70 kts by 20/0600 UTC and to 75 kts twelve hours later.
Outflow enhancement was noted in 20/1200 UTC microwave imagery, although
a recent QuikScat pass indicated that the low-level circulation was
slightly elongated while the microwave image revealed dry air entrainment
from the west. Typhoon Choi-wan had undergone a temporary track change--
an eastward trek--as it rode over the mid-level ridge located to the
southeast.
At 0000 UTC on the 21st Typhoon Choi-wan was moving east-northeastward
at a faster speed of 22 kts from a position approximately 365 nm south-
southwest of Tokyo, Japan. Visible satellite imagery revealed a 12-nm
diameter eye at this time. The system had resumed its intensification,
reaching a peak intensity of 95 kts at 21/0600 UTC. By this time the eye
had expanded to 45 nm in diameter with enhanced outflow continuing to the
north and northeast. However, microwave imagery at 21/1200 UTC indicated
that the upper-level circulation was beginning to tilt slightly to the
east of the LLCC. Typhoon Choi-wan started to weaken as its movement
settled into a northeasterly heading.
The MSW had dropped to 85 kts by 22/0000 UTC as shearing conditions
in the mid-level westerly zone began to separate the deep convection from
the LLCC. Typhoon Choi-wan was accelerating northeastward away from
Japan, being then centred approximately 250 nm east of Tokyo. The
associated deep convection decreased significantly as the intensity of
Choi-wan fell to 80 kts at 22/0600 UTC, to 70 kts six hours later, and
to below typhoon strength at 1800 UTC, by which time extratropical
transition was complete and the last warning issued by JTWC. The last
warning position was near 39.4N, 151.1E, or 450 nm east of Misawa, Japan.
The extratropical remnants of Choi-wan, as tracked by JMA, sped east-
northeastward across the northern Pacific. By 0000 UTC on 24 September
the system had crossed the International Dateline and had weakened into
a 40-kt gale south of the Aleutians.
(Editor's Note: The peak 10-min avg MSW and minimum CP as reported
by JMA were 70 kts and 960 hPa, respectively. CWBT also estimated
the peak intensity of Choi-wan at 70 kts, whereas NMCC's peak MSW
was higher at 80 kts. Choi-wan/Roskas had exited PAGASA's AOR long
before the peak intensity was reached.)
C. Meteorological Observations
------------------------------
The following meteorological observations were compiled and sent by
Huang Chunliang. A special thanks to Chunliang for sending the
information.
1. Peak Wind Reports
--------------------
NOTE: All sustained wind speeds reported below are 10-min avg winds.
(a) Station: Naha, Okinawa (WMO 47936)
Lat 26.2N, Lon 127.7E, Alt 28 m
Winds reached a sustained speed of 36 kts at 19/1350 UTC with a peak
gust of 60 kts recorded at 19/1157 UTC.
(b) Station: Nago, Okinawa (WMO 47940)
Lat 26.6N, Lon 128.0E, Alt 6 m
Peak MSW of 36 kts occurred at 19/1240 UTC and the highest gust
recorded was 62 kts at 19/1502 UTC.
(c) Station: Ojima, Tokyo (WMO 47675)
Lat 34.8N, Lon 139.4E, Alt 74 m
Gale-force winds of 33 kts were reported at 1510 UTC on 21 September,
gusting to a top speed of 64 kts at 21/1934 UTC.
(d) Station: Hachijojima , Tokyo (WMO 47678)
Lat 33.1N, Lon 139.8E, Alt 79 m
A MSW of near typhoon force, 62 kts, was recorded at 21/1510 UTC, while
a top gust of 116 kts was reported at 1434 UTC on the 21st. A gust of
99 kts, occurring at 21/1430 UTC, was highlighted in a JMA local warning.
Winds first reached sustained gale force from the east-northeast at
21/1300 UTC, increasing to storm force by 22/1500 UTC. By 1600 UTC the
MSW began to ease while the SLP started to rise after the minimum of
958.6 hPa was reached at 1533 UTC. Winds continued at gale force for
another two hours from the north until between 1700 and 1800 UTC when
they fell below 35 kts.
(e) Station: Miyakejima, Tokyo (WMO 47677)
Lat 34.1N, Lon 139.5E, Alt 36 m
A MSW of 57 kts was recorded at 21/1300 UTC with a gust of 80 kts at
21/2108 UTC.
(f) Station: Choshi, Chiba (WMO 47648)
Lat 35.7N, Lon 140.9E, Alt 20 m
Sustained winds reached 50 kts at 21/2250 UTC while earlier at 2108 UTC
a peak gust of 68 kts occurred.
(g) Station: Ajiro, Shizuoka (WMO 47668)
Lat 35.1N, Lon 139.1E, Alt 67 m
The MSW reached 39 kts at 21/1550 UTC with a peak gust of 61 kts at
21/1632 UTC.
The following gust reports below were taken from JMA local warnings
and cannot be taken as peak values.
(h) Station: Okinoerabu, Kagoshi (WMO 47942)
Lat 27.4N, Lon 128.7E, Alt 27 m
19/0851 UTC 69 kts
19/1046 UTC 81 kts
19/1155 UTC 82 kts
(i) Station: Yakushima, Kagoshima (WMO 47836)
Lat 30.4N, Lon 130.7E, Alt 36 m
20/0640 UTC 52 kts
(2) Minimum Sea Level Pressure Observations
-------------------------------------------
Naha, Okinawa 985.8 hPa (19/0608 UTC)
Nago, Okinawa 983.8 hPa (19/1004 UTC)
Hachijojima, Tokyo 958.6 hPa (21/1533 UTC)
Note: Only stations that reported sea level pressures below 990 hPa are
included above.
3. Storm Total Rainfall Observations
------------------------------------
The most torrential hourly amount associated with Choi-wan was
recorded in Hachijojima during the 1-hr period ending at 21/1512 UTC,
accumulating to 91.5 mm. The maximum storm total for the period 19/1500
UTC-22/0300 UTC was 281.0 mm.
Other stations (in Japan) which received storm totals above 200 mm
during the period 19/1500 UTC-22/0300 UTC were:
Miyakejima, Tokyo WMO 47677 288.5 mm
Miyake-Ako, Tokyo JMA 44227 316 mm
Miyake-Izu, Tokyo JMA 44229 291 mm
Ojima, Tokyo WMO 47675 211.0 mm
Amagisan, Shizuoka JMA 50427 228 mm
A couple of rainfall amounts from Okinawa for the period 17/1500
UTC-19/1500 UTC include:
Naha, Okinawa WMO 47936 139.5 mm
Nago, Okinawa WMO 47940 105.0 mm
(4) Sources of Data
-------------------
1. Reports prepared by the local meteorological services of Okinawa and
Tokyo, which are under the control of JMA.
2. Raw data on the official web pages of JMA (Japanese version):
http://www.jma.go.jp/>
D. Damage and Casualties
------------------------
No reports of damage or casualties have been reported in association
with Typhoon Choi-wan.
(Report written by Kevin Boyle and Huang Chunliang)
TYPHOON KOPPU
(TC-17W / 0316 / SIKAT)
24 September - 2 October
--------------------------------------------
Koppu: contributed by Japan, means 'cup', and specifically refers to
the constellation Crater
Sikat: PAGASA name, means 'popular'
A. Storm Origins
----------------
A new area of convection developed near 10.0N, 141.0E, or approxi-
mately 220 nm east-northeast of Yap Island. This suspect area was
mentioned in JTWC's STWO at 0600 UTC on 22 September. The development
potential of this broad circulation was assessed as poor. This was
upgraded to fair at 23/2130 UTC as organisation improved. A surface
analysis indicated multiple circulations in the monsoon trough, while
at upper-levels a TUTT cell centred to the northeast was enhancing
outflow. At 24/0230 UTC JTWC issued a TCFA relocating the disturbance
to near 14.9N, 139.4E, or approximately 360 nm west of Saipan.
The first warning on Tropical Depression 17W was issued at 1200 UTC
on 24 September, placing the centre roughly 480 nm west-northwest of
Guam. The exact location of the LLCC was still highly uncertain at
this point as the system remained embedded within the broad trough.
Movement was toward the west-northwest at 10 kts and this heading
continued into the 25th. Intensification was slow and the MSW remained
at 25 to 30 kts through the 25th and 26th due to the hindering effects
of the TUTT cell located to the northeast. During this time the
depression began a slow northward drift, and then finally reached
tropical storm intensity at 27/0000 UTC. A northeastward acceleration
had started in response to a shortwave trough heading toward Japan as
well as to changes in the position of the equatorial and subtropical
ridges.
(Editor's Note: PAGASA issued only four warnings on this system as
Tropical Depression Sikat, well before it had reached tropical storm
intensity. The final PAGASA warning was issued at 0000 UTC on
26 September as Sikat was moving northeastward out of the agency's
AOR.)
B. Track and Intensity History
------------------------------
JMA named this system Koppu just prior to JTWC's upgrade to a 50-kt
tropical storm at 27/0000 UTC. At this time it was located approximately
234 nm south-southwest of Iwo Jima, moving north-northeastward at 16 kts.
After some additional strengthening the intensity of Koppu remained
static at 60 kts for a day or so. Then, following the appearance of a
60-nm ragged eye on the 28/1154 UTC SSM/I pass (infrared satellite
imagery had revealed an eye feature earlier in the day), Koppu was
upgraded to a 70-kt typhoon at 28/1200 UTC, by which time it had slowed
to a 2-kt crawl as it moved through the ridge axis. Earlier, Koppu had
made its closest approach to Iwo Jima at 28/0000 UTC, passing 50 nm to
the west of the island.
Typhoon Koppu began to accelerate once again at 0000 UTC on
29 September. At this time it was centred approximately 160 nm north of
Iwo Jima, moving north-northeastward at 9 kts with the MSW estimated
at 80 kts. A peak intensity of 90 kts was reached at 29/0600 UTC, and
soon afterward, a weakening trend began. The eye faded, deep convection
weakened and the circulation took on an elongated appearance. Koppu was
now undergoing extratropical transition as it continued to accelerate
northeastward at 20 kts.
At 0000 UTC on 30 September, Koppu, barely a typhoon, lay
approximately 390 nm east-southeast of Tokyo, Japan. Convection had
almost completely sheared away and extratropical transformation was
nearly complete. Koppu was downgraded to a tropical storm at 30/0600
UTC and the final warning issued by JTWC. The remnant extratropical
storm could be followed for several more days as it moved south and east
of the Kamchatka Peninsula. The final reference in JMA's High Seas
Bulletins, at 0000 UTC on 2 October, placed the 50-kt storm near
48.0N, 167.0E.
(Editor's Note: The peak 10-min avg MSW estimated by JMA and CWBT was
70 kts, while NMCC's peak intensity was 80 kts. The minimum CP estimated
by JMA was 960 hPa.)
C. Meteorological Observations
------------------------------
The meteorological observations in this section were compiled and
sent by Huang Chunliang. A special thanks to Chunliang for sending the
information.
(1) Hourly Sustained Wind/Pressure Observations from Chichijima
---------------------------------------------------------------
WMO 47971, Lat 27.1N, Lon 42.2E, Alt 3m)
NOTE: All MSW values are 10-min avg winds.
Winds started to increase from the southeast at 1600 UTC,
28 September, and reached gale force six hours later and storm intensity
at 0400 UTC, 29 September. During this period SLP pressure had been
falling (about 3 mb per 3 hours) and reached a minimum of 974.6 mb at
29/0300 UTC. The highest hourly sustained winds (from the south-
southwest) occurred at 29/0400 UTC, peaking at 55 kts. Winds quickly
dropped to gale force and had fallen below 30 kts by 29/0700 UTC.
A peak wind gust of 108 kts was recorded on Chichijima, Japan, at
29/0300 UTC and was the third highest gust measured at this station.
Only two storms have brought stronger gusts: Super Typhoon Marge of
1983 (116 kts) and Typhoon Ben of 1986 (114 kts). In the history of the
station, only one typhoon has brought a MSW higher than Koppu and that
was Joan of 1997 (62 kts). The highest sustained winds observed in
association with Koppu were 60 kts.
Other gust reports from Chichijima include: a gust of 69 kts at
28/2224 UTC, 78 kts at 28/2320 UTC, and 93 kts at 29/0042 UTC. All of
these observations were highlighted in the JMA local warnings and cannot
be regarded as the peak values.
(2) Sources of Data
-------------------
This report was distilled, translated and edited from the raw data
on the official web pages of JMA (Japanese version):
http://www.jma.go.jp/>
(3) Wind/Pressure Reports from Iwo Jima
---------------------------------------
The MSW reached a maximum of 38 kts at 28/0600 UTC and 28/1500 UTC.
A peak gust of 59 kts was recorded at 27/2100 UTC and a pressure of 982.1
hPa was also reported at this time. Also, a minimum pressure of 980 hPa
was reported at 28/0000 UTC. These reports were from 3-hourly synoptic
observations and cannot be taken as peak/minimum values.
D. Damage and Casualties
------------------------
There have been no reports of damage or casualties resulting from
Typhoon Koppu.
(Report written by Kevin Boyle and Huang Chunliang)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for September: No tropical cyclones
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for September: 1 moderate tropical storm
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Southwest Indian Ocean tropical cyclones are the warnings issued by
the Tropical Cyclone Warning Centre on La Reunion Island, part of
Meteo France (MFR), and the Regional Specialised Meteorological Centre
for the basin. However, tropical cyclones in this region are named
by the sub-regional warning centres on Mauritius and Madagascar with
longitude 55E being the demarcation line between their respective
areas of warning responsibility. The La Reunion centre only advises
these agencies regarding the intensity of tropical systems. References
to sustained winds imply a 10-minute averaging period unless otherwise
stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from MFR's coordinates by usually
40-50 nm or more. The JTWC warnings are also the source of the
1-minute average maximum sustained wind values included in the
tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Southwest Indian Ocean Tropical Activity for September
------------------------------------------------------
The tropical storm season in the Southwest Indian Ocean west of 90E
got underway early with the formation of Tropical Storm Abaimba. Such
early-season storms are unusual but not all that rare in this basin.
JTWC initiated warnings on TC-01S on 29 September and upgraded the system
to minimal tropical storm status the next day. The system intensified
markedly on 1 October and was named Abaimba by the Meteorological Service
of Mauritius. Tropical Storm Abaimba meandered around at a very low
latitude several hundred miles west-northwest of Diego Garcia and had
dissipated by 4 October.
TROPICAL STORM ABAIMBA
(MFR-01 / TC-01S)
29 September - 4 October
--------------------------------------------
Abaimba: contributed by Tanzania
A. Storm Origins
----------------
The precursor to this early-season tropical storm in the Southwest
Indian Ocean was an area of convection which formed about 600 nm west
of Diego Garcia early on 29 September. JTWC issued a STWO at 0400 UTC,
noting that satellite imagery indicated cycling deep convection near
an elongated LLCC with the convection wrapping into the center. The
development potential was assessed as fair based on the presence of good
diffluence aloft and weak to moderate vertical shear. MFR issued their
first bulletin on Tropical Disturbance 01 at 0600 UTC, and JTWC followed
with a TCFA at 0930 UTC which relocated the disturbance to a position
approximately 590 nm west-northwest of Diego Garcia.
JTWC issued the first warning on Tropical Cyclone 01S at 1800 UTC,
again relocating the center--this time to a point 505 nm west-northwest
of Diego Garcia. The MSW (1-min avg) was estimated at 30 kts, based on
CI estimates of 25 and 35 kts. The system was quasi-stationary with
the LLCC located just east of the deepest convection. At 0000 UTC on
30 September MFR upped the MSW (10-min avg) to 30 kts, which qualified
the system for formal tropical depression status. JTWC upped their
MSW estimate to 35 kts (1-min avg) at 0600 UTC; at the time TC-01S was
located about 475 nm west-northwest of Diego Garcia, moving southeast-
ward at 4 kts. The LLCC was partially-exposed to the northeast of the
deep convection. The intensity remained static for the remainder of
the 30th as the depression continued moving slowly east-southeastward.
It was forecast to turn to the southwest in 12-24 hours as a low to mid-
level ridge built to the south.
B. Storm History
----------------
At 0600 UTC on 1 October the center of TC-01S was located roughly
420 nm west-northwest of Diego Garcia, moving very slowly southwestward.
Poleward outflow had improved, and the LLCC was no longer exposed. JTWC
upped the MSW to 50 kts (1-min avg), based on CI estimates of 35 and 45
kts plus QuikScat data. Also, MFR and the Mauritius Meteorological
Service upgraded the system to tropical storm status with the latter
agency assigning the name Abaimba. MFR bumped up their MSW estimate
from 30 to 45 kts (10-min avg) at 0600 UTC. However, at 1800 UTC MFR
lowered the intensity to 40 kts. JTWC's MSW remained at 50 kts, but
the warning noted that there was evidence of some cooler air infiltrating
the western side of Abaimba's circulation.
A SSM/I pass at 02/0451 UTC revealed a fully-exposed LLCC with deep
cycling convection located 100 nm to the west under 20-30 kts of north-
easterly shear. JTWC downgraded the MSW to 30 kts (1-min avg) and placed
the center about 290 nm west-northwest of Diego Garcia, moving south-
eastward at 6 kts. MFR's intensity remained at 35 kts, but this was
lowered to 30 kts at 1200 UTC. The factors responsible for Tropical
Storm Abaimba's sudden weakening were adjudged to be a lack of upper-
level outflow, increased vertical shear, and entrainment of cooler (and
likely drier) air. Interestingly, at 0600 UTC on 3 October, JTWC upped
the MSW back to 35 kts (1-min avg) and forecast Abaimba to strengthen
steadily, reaching 55 kts in 48 hours. The storm at this time was
located approximately 335 nm west-northwest of Diego Garcia, moving
slowly southwestward at 3 kts. Abaimba's organization was improving
somewhat, and the system was forecast to move into a more favorable
environment of increased outflow and reduced vertical shear.
However, Abaimba continued to present a very poorly-organized
appearance in satellite imagery. MFR dropped the MSW to 25 kts at
1200 UTC, although the bulletin noted that stronger winds were likely
occurring in isolated spots in the southwestern semicircle. At 1800 UTC
JTWC once more dropped the intensity to 30 kts, but still forecast the
system to recover and undergo some modest strengthening. At 0600 UTC
on 4 October MFR and JTWC decreased their MSW estimates to 20 kts and
25 kts, respectively. The JTWC warning indicated that CI estimates
were 25 and 30 kts, and the agency's forecast still called for Abaimba
to re-intensify to tropical storm strength. This optimistic forecast
failed to verify, however, and MFR issued their final bulletin on
the system at 1200 UTC. JTWC likewise issued their final warning on
the dissipating system at 1800 UTC, placing the center about 460 nm
west of Diego Garcia and moving west-northwestward at 6 kts. All deep
convection associated with the LLCC had dissipated during the previous
twelve hours.
C. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Tropical
Storm Abaimba.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for September: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for September: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for September: No tropical cyclones
*************************************************************************
EXTRA FEATURE
In order to shorten the amount of typing in preparing the narrative
material, I have been in the habit of freely using abbreviations and
acronyms. I have tried to define most of these with the first usage
in a given summary, but I may have missed one now and then. Most of
these are probably understood by a majority of readers but perhaps a
few aren't clear to some. To remedy this I developed a Glossary of
Abbreviations and Acronyms which I first included in the July, 1998
summary. I don't normally include the Glossary in most months in
order to help keep them from being too long. If anyone would like to
receive a copy of the Glossary, please e-mail me and I'll be happy
to send them a copy.
*************************************************************************
AUTHOR'S NOTE: This summary should be considered a very preliminary
overview of the tropical cyclones that occur in each month. The cyclone
tracks (provided separately) will generally be based upon operational
warnings issued by the various tropical cyclone warning centers. The
information contained therein may differ somewhat from the tracking and
intensity information obtained from a "best-track" file which is based
on a detailed post-seasonal analysis of all available data. Information
on where to find official "best-track" files from the various warning
centers will be passed along from time to time.
The track files are not being sent via e-mail. They can be retrieved
from the archive sites listed below. (Note: I do have a limited e-mail
distribution list for the track files. If anyone wishes to receive
these via e-mail, please send me a message.)
Both the summaries and the track files are standard text files
created in DOS editor. Download to disk and use a viewer such as
Notepad or DOS editor to view the files.
The first summary in this series covered the month of October,
1997. Back issues can be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Michael Pitt, and
Chris Landsea):
http://australiasevereweather.com/cyclones/>
http://www.typhoon2000.ph>
http://mpittweather.com>
ftp:// ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/>
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.met-office.gov.uk/sec2/sec2cyclone/sec2cyclone.html>
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the complete Annual Tropical
Cyclone Report (ATCR) for 2002 (2001-2002 season for the Southern
Hemisphere). ATCRs for earlier years are available also.
The URL is: http://199.10.200.33/jtwc.html>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2002 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2002 Atlantic
and Eastern North Pacific cyclones are now available, as well as
track charts and reports on storms from earlier years.
The URL is: 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]
Huang Chunliang: (Assistance with Western Northwest Pacific, South
China Sea)
E-mail: [email protected]
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: [email protected]
*************************************************************************
*************************************************************************
|
Document: summ0309.htm
Updated: 26th October 2006 |
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