[Index]
Monthly Global Tropical Cyclone Summary April 2003
[Summaries and Track Data] [Prepared by Gary Padgett]
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Monthly Global Tropical Cyclone Summary April 2003 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
APRIL, 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.)
*************************************************************************
APRIL HIGHLIGHTS
--> Very intense cyclone forms south of Indonesia--weakens before
making landfall in Western Australia
--> First Northwest Pacific super typhoon of the year forms
--> First April Atlantic tropical cyclone on record forms
*************************************************************************
***** Feature of the Month for April *****
WESTERN HEMISPHERE TROPICAL CYCLONE NAMES for 2003
Tropical cyclones in the Atlantic Ocean, Gulf of Mexico, and
Caribbean Sea are assigned names by the Tropical Prediction Center/
National Hurricane Center in Miami, Florida. A separate alphabetical
set of alternating male/female names is used each year with the name
of the first tropical storm beginning with the letter "A". Names are
repeated every six years. The names of hurricanes which cause a lot
of damage and/or fatalities are usually retired from the list with
another name of the same alphabetical rank and gender replacing it.
Following the 2002 season, the names Isidore and Lili were retired.
Isidore has been replaced with Ike, and Lili was initially replaced
with Laura, but since that name was previously used to name a tropical
storm in 1971, the decision has been made not to use Laura but rather
to choose another name at next year's WMO committee meeting.
EDITOR'S SOAPBOX: This rule that no pre-1979 (the year the current
Atlantic naming list was initiated) tropical cyclone name can be used
as a replacement name apparently is of very recent conception, and
personally to me is most objectionable and inconsistent. It essentially
makes every storm moniker utilized prior to 1979 a retired name. It
is also very inconsistent considering that of the names currently in
the six-year rotating Atlantic list, twelve were used prior to 1979--
some up to 4 or 5 times. And while on the subject of retiring tropical
cyclone names, there is another glaring inconsistency which even after
18 years should be addressed. In 1985 Hurricane Gloria struck the
Northeast U. S., causing around $900 million in losses and 4 fatalities.
Later, Hurricane Juan struck coastal Louisiana, claiming 12 lives and
causing massive flooding which resulted in $1.5 billion in damages.
Yet, Gloria was retired and Juan remains in the list! (End Soapbox)
The highest number of tropical storms named in one season in the
Atlantic was 19 during the very active 1995 season. The most active
Atlantic tropical cyclone season on record was 1933, in which 21 storms
were charted, but of course that season pre-dates the formal naming of
tropical cyclones. The active 1969 season is credited with 17 tropical
cyclones (plus one subtropical storm), but only 13 were actually named
operationally. Several of the systems began as hybrid/subtropical
storms and forecasters at the time were still debating how to classify
this type of storm system, and so they remained unnamed. A few years
later several tracks were added to the official Best Tracks database.
Two of these unnamed storms were hurricanes, thus giving 1969 a total
of 12 hurricanes--the current record for the Atlantic.
The list of names for 2003 is the same one used during the inactive
hurricane season of 1997 when only seven tropical cyclones were named.
This same set of names was also used during the fairly active 1985
season when six hurricanes made landfall along the United States
coastline: Bob, Danny, Elena, Gloria, Juan, and Kate.
TPC/NHC also has warning responsibility for the Eastern North
Pacific Ocean from the west coast of Mexico out to longitude 140W.
Six separate alphabetical sets of names are used for this basin in
the same manner as in the Atlantic. Initially, the Eastern Pacific
name sets contained only 21 names, omitting "Q" and "U" and ending
with the letter "W", as in the Atlantic. When the active 1985 season
threatened to exhaust the list, the names Xina, York and Zelda were
drafted to accommodate any additional storms which might develop.
(Hurricane Xina was named in late October, 1985.) The decision was
made sometime in the latter 1980s to extend the list with these three
names in odd-numbered years, and to add the names Xavier, Yolanda and
Zeke in even-numbered years (to preserve the alternating gender
scheme). During the Northeast Pacific's year of record activity in
1992, all 24 names were allotted to tropical cyclones forming east of
140W, ending with Tropical Storm Zeke in late October. Had more storms
developed, they would have been named with the letters of the Greek
alphabet (Alpha, Beta, etc), which is also the backup plan for the
Atlantic basin in case more than 21 tropical storms develop in a single
season.
The list for this year is the same one used in the active El Nino
season of 1997, when 17 storms were named, including the very intense
Hurricanes Guillermo and Linda. Also in 1997, Hurricane Pauline was
very destructive and deadly to the Acapulco area, and that name has
been retired, being replaced with Patricia in this year's set. The
name Kenna has been retired following the 2002 season and will be
replaced in the list for 2008 with Karina.
The Central Pacific Hurricane Center, located in Honolulu, has
tropical cyclone warning responsibility for that portion of the North
Pacific Ocean lying between longitudes 140W and 180. The majority of
the tropical storms and hurricanes seen in that region are visitors
from east of 140W, but on the average about one tropical storm forms
in the Central Pacific each year, and when this happens, the storm is
given a Hawaiian name. The list consists of four sets of twelve
names each, using only the letters of the Hawaiian alphabet. All the
names are used--the first storm to form in a given year is assigned
the next available name on the list. Three tropical storms were named
by CPHC in 2002: Alika, Ele, and Huko, the latter two crossing the
International Dateline to become typhoons in the Western North Pacific.
Names for 2003 are (** indicates name has already been assigned):
ATLANTIC EASTERN PACIFIC CENTRAL PACIFIC
----------------------- ----------------------- ---------------
Ana ** Larry Andres ** Marty Ioke
Bill Mindy Blanca Nora Kika
Claudette Nicholas Carlos Olaf Lana
Danny Odette Dolores Patricia Maka
Erika Peter Enrique Rick Neki
Fabian Rose Felicia Sandra Oleka
Grace Sam Guillermo Terry Peni
Henri Teresa Hilda Vivian Ulia
Isabel Victor Ignacio Waldo Wali
Juan Wanda Jimena Xina Ana
Kate Kevin York Ela
Linda Zelda Halola
ADDENDA TO PREVIOUS SUMMARIES
-----------------------------
(1) Tropical Cyclone Beni - January/February, 2003
Matthew Saxby of Queanbeyan, New South Wales, sent me some press
releases concerning the effects of the former Tropical Cyclone
Beni in Australia in early February. Most notable was the account
of a flash flood in the city of Tamworth, located in northwestern
New South Wales. More than 150 mm of rain fell in less than one
hour, sending a torrent of water out of the mountains above the
city. The wall of water picked up cars, pushing them along the
street, destroyed brick retaining walls, lifted pavement and
caused extensive damage to many homes. In the central business
area the drainage system was unable to cope and water entered
scores of shops, destroying merchandise. Water also entered many
homes when their guttering systems failed. Fortunately, the
torrential rain fell in a narrow strip and the flooding affected
only a limited area. The damage bill was estimated to be several
million dollars. (A thanks to Matthew for sending me the reports.)
(2) Super Typhoon Pongsona - December, 2002
Roger Edson has informed me that the National Weather Service
assessment of Pongsona is now available on the web. It can be
downloaded from an FTP site at:
http://www.nws.noaa.gov/om/> (File size is 2+ Mbytes)
(3) Typhoon Vamei - December, 2001
Michael Padua alerted me to an article discussing the formation of
the near-equatorial Typhoon Vamei near Singapore. The URL is:
http://www.jpl.nasa.gov/earth/features/typhoonvarmei.cfm>
(Note: The typhoon's name is misspelled in the link address
and in the article.)
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for April: 1 tropical storm
Atlantic Tropical Activity for April
------------------------------------
Prior to 2003 no tropical cyclone had ever been noted in the Atlantic
basin in April--the only month without any tropical cyclone activity.
That changed on 22 April when Subtropical Storm Ana was reclassified as
Tropical Storm Ana southeast of Bermuda. Currently, only one other
April subtropical storm is listed in the Atlantic Best Track database
(1992); however, the possibility exists that some additional such
system(s) could be added during the on-going reanalysis of the Atlantic
historical database. Once having created such a significant moment in
meteorological history, however, Ana scooted on rather uneventfully off
to the east, soon becoming extratropical. It is interesting to note that
almost all the out-of-season Atlantic tropical cyclones on record (at
least from December through April) have formed in the subtropics from
initially baroclinic systems. The last Atlantic tropical cyclone to form
outside the nominal June to November season was Hurricane Lili in
December, 1984, while the last pre-season storm was Tropical Storm Arlene
in May, 1981.
TROPICAL STORM ANA
(TC-01)
16 - 27 April
--------------------------------------
A. Introduction
---------------
Tropical Storm Ana was not all that much from a meteorological point
of view, but it was very significant climatologically. When named as a
subtropical storm by TPC/NHC at 0300 UTC on 21 April, it became only the
second subtropical storm currently on record for the month of April, the
other one occurring in April, 1992. This, however, is not particularly
all that significant given that the classification of subtropical storms
has not been applied consistently over the years since it was first
introduced to the public in 1972. There are quite a few April systems
during the intervening years which possibly qualify as subtropical
storms, and there is a possibility some of these will be added to the
official database during the ongoing re-analysis of Atlantic tropical
and subtropical cyclones.
Ana's real claim to fame is that it is the first tropical cyclone ever
noted in the Atlantic during the month of April. It is possible, and
even probable, that prior to the satellite era occasional short-lived
tropical storms formed somewhere in the vast Atlantic subtropics, but it
is highly likely that Ana is the first April tropical cyclone to form
since satellites began monitoring the oceans round the clock in the late
1960s. With the reclassification of Ana as a tropical storm on the
morning of 22 April, all months of the year have now seen at least one
Atlantic tropical storm or hurricane.
B. Storm Origins
----------------
Information for the pre-naming stage of Ana comes from a track and
comments sent to the author by David Roth, a meteorologist at the
Hydrometeorological Prediction Center in Camp Springs, Maryland. A
weak LOW had formed by 1200 UTC on 16 April about 265 nm southeast of
Miami. The system drifted generally eastward, being located about 400 nm
east-southeast of Miami by 17/0600 UTC. David's track relocates the LOW
to a position approximately 400 nm southwest of Bermuda at 1200 UTC. The
system was still quite weak with peak winds likely in the 15-20 kt range.
Early on the 18th moderate shallow convection was beginning to curl
around the LLCC and a ship reported 35-kt winds north of the center.
The LOW drifted very slowly in a general northerly direction on the
18th and 19th. At 19/1200 UTC the center was approximately 225 nm west-
northwest of Bermuda. Based on ship reports, David estimates that
maximum winds were near 25 kts around this time and through most of the
20th. However, Mark Lander stated that QuikScat data indicated winds
of around 50-55 kts on the 19th and 20th. According to David, the
LOW was never analyzed with a cold front on HPC charts, but probably
had fronts aloft, which is a characteristic of subtropical systems.
Even after Ana had been named by TPC/NHC, a warm front was nearby but
was draped slightly over the system instead of being linked into the
center. During the formative stages of Ana, a plume of tropical
moisture was tapped by the system, leading to significant flooding in
Puerto Rico.
C. Storm History
----------------
The LOW began to drift east-southeastward on 20 April, and by 0000 UTC
on the 21st was located approximately 100 nm southwest of Bermuda. Winds
had increased to 35 kts, and at 21/0300 UTC TPC/NHC issued the first
advisory on Subtropical Storm Ana. The initial storm discussion noted
that Ana was located under a significant upper-level trough so the
classification would be subtropical. TAFB had estimated winds of
35-40 kts with an ST classification while SAB assigned a T2.5 rating.
Recent QuikScat data indicated widespread 30-40 kt winds within 60-75 nm
of the center and peak winds as high as 55 kts. However, it was felt
that these could have been too high due to precipitation, so the MSW was
estimated at a more conservative 35 kts. A gale warning had been issued
for Bermuda during the afternoon of the 20th, and this was changed to
a tropical storm warning at the time Ana was named as a subtropical
storm.
Deep convection diminished somewhat during the night, but a small area
had reappeared near the center by the morning of the 21st. TAFB and SAB
had reversed their classifications with TAFB rating Ana at only T1.5
while SAB's analyst rendered an ST2.5 rating. The tropical storm warning
for Bermuda was discontinued during the morning after the storm had
passed to the south of the island, moving eastward. During the evening
of 21 April, Ana looked rather tropical. Both TAFB and SAB rated the
storm at T2.5 at 22/0000 UTC, and a TRMM overpass around 21/2330 UTC
suggested that an eye might be forming. However, by advisory time (0300
UTC) the convection had become less organized, and an AMSU pass at 2200
UTC did not show a warm core, so Ana remained subtropical. QuikScat
data suggested that the cyclone might have strengthened slightly.
At 22/0900 UTC a ship reported winds of 44 kts from a position 50 nm
south of the center, and AMSU data was by now showing a slightly warm
core near the surface and aloft. Based on the evidence of a warm core
and the ship report, which suggested a fairly small radius of maximum
winds, Ana was reclassified as a tropical storm in the 1500 UTC advisory,
the first April Atlantic tropical storm on record. The cyclone was
located roughly 400 nm east-southeast of Bermuda, moving eastward at
about 14 kts with the MSW estimated at 45 kts. The storm continued
sailing eastward rather uneventfully across the central Atlantic. The
MSW was decreased to 40 kts at 23/0300 UTC--satellite intensity estimates
from SAB, AFWA, and TAFB were 45, 35, and 30 kts, respectively.
By 0900 UTC the low-level cloud center had become less defined. Deep
convection was sheared well to the east-northeast of the center with
little or no evidence of banding features. The 1500 UTC discussion
noted that the deep convection structure no longer looked tropical with
all of the deep convection well north and east of the center without
any curvature. Dvorak estimates were below 35 kts and a 2200 UTC Quik-
Scat pass showed no winds above 30 kts. However, at 0300 UTC a ship
had reported 41-kt winds about 110 nm southeast of the center, so the
MSW remained at 40 kts.
The intensity was reduced to 35 kts at 2100 UTC. A burst of deep
convection had recently been noted just northeast of the LLCC, so Ana
was maintained as a tropical storm for one more advisory cycle. By
0300 UTC on 24 April satellite imagery indicated that it was becoming
difficult to separate the convection and circulation of Ana from a
nearby frontal zone. The latest QuikScat pass had shown 35-kt winds
north of the center primarily within the frontal zone and winds of only
20-25 kts to the south. The storm was becoming extratropical so the
24/0300 UTC advisory was the final one from TPC/NHC. Ana was then
located approximately 1025 nm west-southwest of the westernmost Azores.
The remnant extratropical LOW continued moving eastward, gradually
turning more to the northeast. The LOW passed about 325 nm south of
the northwestern Azores around 1800 UTC on 26 April and was located
roughly 400 nm east-northeast of the Azores by 27/1200 UTC.
As the extratropical remnants of Ana passed through the Azores early
on the 27th, Ponta Delgada reported 22 mm of rain between 0000 and 0600
UTC. The LOW moved northeastward toward the British Isles and deepened
to 982 mb, crossing the Irish Sea and Scotland on the 28th. The remnants
of Ana brought some much needed rain to the UK after a length dry spell.
(Thanks to Kevin Boyle for sending me this tidbit of information.)
D. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Tropical
Storm Ana.
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for April: No tropical cyclones
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for April: 1 super typhoon
Northwest Pacific Tropical Cyclone Activity for April
-----------------------------------------------------
The only tropical cyclone to form in April in the Northwest Pacific
basin turned out to be the first April super typhoon in six years, and
ultimately became one of the longest-lived Northwest Pacific tropical
cyclones on record. The cyclone trekked from its region of formation
near Pohnpei on 9 April to a recurvature east of the Philippines,
eventually making landfall on Kyushu on the 25th. The extratropical
remnants of Kujira continued northeastward and eastward, crossing the
Dateline on the 29th and were last mentioned on the 30th far to the
south of the western Aleutian Islands. Another remarkable feature of
Kujira was that it had three distinct peaks in intensity based on JTWC's
analysis.
The report on Kujira below was written by myself and Kevin Boyle with
significant contributions by Huang Chunliang. A special thanks to Kevin
and Chunliang for their assistance.
SUPER TYPHOON KUJIRA
(TC-02W / TY 0302 / AMANG)
9 - 30 April
----------------------------------------------
Kujira: contributed by Japan, is the Japanese word for 'whale'
Amang: PAGASA name, is a Filipino male nickname
A. Storm Origins
----------------
An area of convection developed in early April--around 0600 UTC on
7 April it was located approximately 400 nm southeast of Chuuk. Micro-
wave and animated multi-spectral imagery revealed disorganized cycling
deep convection over a broad surface trough while a 200-mb analysis
indicated weak diffluence aloft with marginal vertical shear. The
disturbance shifted eastward and on the 8th was located roughly 250 nm
south-southwest of Pohnpei. The system was still poorly-organized, but
as the 8th progressed convection continued to consolidate east of the
region of troughing. A 08/1924 UTC SSM/I pass indicated developing
banding deep convection in the southeastern quadrant, and an upper-air
analysis revealed favorable diffluence aloft with weak to marginal shear.
At 2200 UTC JTWC issued a TCFA for the LLCC located about 250 nm south-
southeast of Pohnpei.
B. Storm History
----------------
The first JTWC warning on Tropical Depression 02W was issued at 0000
UTC on 9 April, placing the center about 230 nm south-southeast of
Pohnpei. Only six hours later the depression was upgraded to tropical
storm status, moving northwestward at 4 kts. Satellite-derived intensity
estimates were 35 kts, and the system exhibited improved banding in the
southwestern quadrant with persistent convection. An upper-air analysis
indicated good cross-equatorial outflow with moderate diffluence and
weak vertical shear. (JMA classified the system as a depression at
09/1200 UTC but did not upgrade until 11/0000 UTC.) JTWC upped the MSW
to 40 kts at 1800 UTC--the storm was then centered approximately 125 nm
southeast of Pohnpei and moving slowly north-northwestward at 7 kts. The
LLCC was still slightly exposed to the east of the deep convection.
Tropical Storm 02W did not intensify significantly on the 10th and
11th as it moved generally northwestward, turning more to the west-
northwest on the 11th. A QuikScat pass around 10/1200 UTC depicted
winds of 40 kts associated with the LLCC. At 11/0000 UTC TS-02W was
centered approximately 100 nm north of Pohnpei, moving west-northwestward
at 7 kts. At this juncture JMA upgraded the system to tropical storm
status, assigning the name Kujira. (NMCC also upgraded the system to
tropical storm status and initiated warnings at 0000 UTC.) By 1800 UTC
Kujira had begun tracking westward as the subtropical ridge to its north
built in response to a mid-latitude trough from the Asian mainland moving
up the backside of the ridge. The LLCC was no longer exposed, and Kujira
seemed set to begin some significant intensification.
By 12/0000 UTC Kujira's outflow had improved considerably and JTWC
upped the MSW to 55 kts. At 0600 UTC the storm was located about 200 nm
north-northeast of Chuuk, moving westward at 10 kts. A 12/1133 UTC TRMM
image revealed that Kujira had developed well-defined banding features
on both the equatorward and poleward sides. With CI estimates ranging
from 45 to 65 kts at 1200 UTC, JTWC opted to let the MSW remain at
55 kts. However, at 1800 UTC Kujira was upgraded to a 65-kt typhoon (by
JTWC) when located 175 nm north of Chuuk. A banding eye feature had
developed with well-defined radial outflow over the system. The MSW was
further increased to 75 kts at 13/1200 UTC and to 90 kts at 14/0000 UTC,
based on CI estimates of 77 and 90 kts. (Also at 14/0000 UTC, JMA
upgraded Kujira to typhoon status; NMCC had done so at 13/1800 UTC.)
The typhoon was located about 235 nm southeast of Guam, still trekking
westward. A 25-nm eye was evident in multi-spectral and SSM/I imagery.
By 14/0600 UTC the eyewall appeared better developed and the intensity
was upped to 100 kts with Kujira then centered approximately 200 nm
south-southeast of Guam. The storm's heading had by this time become
west-northwesterly as it tracked toward a developing weakness in the
subtropical ridge over Luzon, the weakness being enhanced by an
approaching shortwave trough located over eastern China. The intensity
was increased to 110 kts at 1200 UTC and further to 120 kts at 1800 UTC,
based on CI estimates of 102 and 115 kts. Kujira was then located about
140 nm south-southwest of Guam and sported a 29-nm eye with a closed
eyewall.
A TRMM pass at 14/2109 UTC indicated possible concentric eyewalls.
The intense typhoon continued west-northwestward on 15 April, slowly
strengthening. JTWC upped the MSW to 125 kts at 15/0000 UTC, based on
CI estimates of 115 and 127 kts. At 1800 UTC Kujira was located about
375 nm west-southwest of Guam, or approximately 190 nm north of Yap,
moving west-northwestward at 12 kts. Dvorak intensity estimates had
reached 127 and 140 kts, so JTWC increased the MSW to 130 kts, making
Kujira the year's first super typhoon. (It was also the first typhoon
of 2003.) JMA's and NMCC's intensity estimates at the time were 85 kts
and 120 kts (10-min avg), respectively. Enhanced infrared imagery
indicated that the system was forming concentric eyewalls. Super Typhoon
Kujira reached its peak intensity of 135 kts at 16/0000 UTC when located
approximately 215 nm north-northwest of Yap.
At 0000 UTC on 16 April Super Typhoon Kujira was moving west-
northwestward at 13 kts at its peak intensity of 135 kts, gusting to
165 kts. (NMCC's and JMA's peak 10-min avg MSW estimates were 120 kts
and 90 kts, respectively, while the minimum CP estimated by JMA was
930 mb.) Kujira was an average-sized system with 100-kt winds
extending 35 nm from the center, storm-force winds up to 80 nm (85 nm
in the northeast sector), and gales as far out as 175 nm in the north-
east and northwest quadrants and 130 nm to the southwest and southeast.
The MSW began to drop at 16/1200 UTC as the typhoon crossed 135E and
into PAGASA's AOR. PAGASA initiated bulletins at this time, assigning
their internal name, Amang, and setting the initial intensity at 90 kts
(10-min avg).
By 17/0000 UTC, the MSW had fallen to 105 kts, the eye had
disappeared, and the system had begun to interact with a mid-latitude
zone. Also, dry air from the northwest was being entrained into the
southwest quadrant. Kujira/Amang was by now moving on a more westerly
track under the steering influence of the subtropical ridge to the north-
west. This westward heading helped to keep the majority of the vertical
wind shear (as evidenced on the CIMSS Wind Shear Products) north of the
system for the near term. By 18/0000 UTC, Kujira/Amang had moved to a
position approximately 560 nm east of Manila. Despite the negative
effects of dry air entrainment and some shearing over the northern
portion of the system, the MSW unexpectedly increased to 115 kts, and by
0600 UTC had reached a secondary peak of 125 kts. (During this time,
PAGASA raised their MSW from 65 kts to 80 kts while NMCC and JMA kept
their intensities constant at 90 kts and 85 kts, respectively.)
Kujira/Amang was, at this time, exhibiting a well-defined 14-nm diameter
geometric eye, as seen on multi-spectral, enhanced infrared and micro-
wave imagery. SSM/I imagery at 18/0929 UTC indicated that Kujira was
possibly beginning a concentric eyewall cycle.
Water vapor imagery at 0000 UTC on 19 April showed that the longwave
trough had exited the Western Pacific but that the polar outflow was
being inhibited. Kujira/Amang had begun to weaken again as it turned
northwestward in response to a weakness in the subtropical ridge. The
MSW had dropped to 85 kts by 20/0000 UTC, and microwave imagery showed
signs of erosion in the southern eyewall. However, outflow conditions
again improved, and six hours later Kujira began a third
re-intensification phase with the MSW reaching 100 kts by 20/1200 UTC.
(JMA increased their intensity by 5 kts to 80 kts while NMCC upped
theirs from 80 kts to 90 kts. PAGASA held the MSW at 70 kts. (All the
MSW values from the Asian TCWCs represent a 10-min averaging period.)
At 0000 UTC on 21 April Kujira/Amang was located approximately 425 nm
south-southeast of Taipei, Taiwan, tracking northwestward at 6 kts.
HKO began monitoring the cyclone through the issuance of advisories at
this time. The maximum sustained winds were still blowing at 100 kts,
although cloud tops were warming slightly in satellite images. A
weakening trend followed (this time for good!) and the 20 nm cloud-
filled, irregular eye weakened and had disappeared by 21/1200 UTC. At
1800 UTC, Kujira was downgraded to a 60-kt tropical storm.
The next day, at 0000 UTC on 22 April, Kujira was moving north-
northwestward approximately 315 nm south-southeast of Taipei, Taiwan
(JTWC 20.1N, 123.3E; JMA 20.2N, 124.4E) with an estimated MSW of 55 kts.
The deep convection at this time was sheared approximately 25 nm to the
northeast of the fully-exposed LLCC. The system had turned northward by
22/1800 UTC, squeezing into the weakness between one ridge centered to
the northeast and another located in the South China Sea. Meanwhile,
the forward speed had slowed to a 2-kt crawl.
Movement became more erratic early on the 23rd as Kujira wobbled
first to the west then west-southwestward before grinding to a halt
near 21.0N, 122.5E (or approximately 250 nm south-southeast of Taipei,
Taiwan) at 0600 UTC. (Steering currents were now at lower-levels, i.e.,
850-mb and below.) Despite its status as a minimal tropical storm,
moderate wind shear environment, and the effects of sub-26 C SSTs,
satellite representation of the system was quite impressive. The LLCC
moved back under the deep convection with well-marked spiral-banding
features.
Late on the 23rd, Kujira began to drift slowly northward, then
north-northeastward by 24/0000 UTC. After making its closest approach
to Taipei (190 nm to the south-southeast), the tropical storm began to
accelerate away from the island of Taiwan. Its forward speed had
increased to 24 kts by 24/1800 UTC, and despite the increasingly hostile
environment, Kujira maintained its deep convection and intensity.
(PAGASA and HKO both ceased issuing bulletins at 24/1200 UTC and
24/1800 UTC, respectively, as Kujira/Amang departed their AORs.)
The north-northeast translational speed had increased to 37 kts by
25/0600 UTC as Kujira, now located in the warm sector of a mid-latitude
LOW, was making landfall on the Japanese island of Kyushu near Ushibuka.
This is the earliest recorded case of a tropical cyclone making landfall
in Japan. JTWC issued the last advisory--Warning #66--at 25/0600 UTC,
the system then being considered extratropical. (JTWC also downgraded
Kujira to a tropical depression on this final warning while JMA had
downgraded the cyclone three hours earlier.) JMA continued to monitor
Kujira during its extratropical stage until the end of the month when
the LOW had crossed the International Dateline.
In terms of the number of warnings issued, the long-lived Kujira was
thirteen short of the longest-lived Western Pacific tropical cyclone on
record, Typhoon Rita of 1972, and three shy of Typhoon Opal (1967). A
total of 67,66 and 61 warnings were required for Super Typhoon Wayne
(1986), Typhoon Tess (1972) and Typhoon Nat (1991), respectively.
C. Meteorological Observations
------------------------------
(1) Karl Hoarau passed along the following surface observations in
association with Kujira. (A thanks to Karl for sending the
information.) At 0900 UTC, 25 April, station WMO 47815 recorded
a pressure of 999.8 hPa. This was just after the passage of the
center near the station. Ishigakijima (WMO 47918) recorded a SLP
of 1000.5 hPa with a 10-min avg wind of 30 kts at 24/0900 UTC.
The maximum gust was not reported.
(2) Huang Chunliang has sent an extensive amount of information from
a Taiwanese station and from several Japanese stations. (A thanks
to Chunliang for sending along the observations.)
Station Lan Yu, Taiwan (WMO 46762/59567, 22.03N, 121.55E, Alt 325 m)
experienced a rather extensive period of gale-force winds on 22, 23,
and 24 April. (All the winds given for this station represent 10-min
avg sustained winds.) At 22/0400 UTC Lan Yu reported NNE winds of
39.5 kts with a SLP of 972.8 hPa. Then, beginning at 0700 UTC, the
station experienced winds near or exceeding gale force through
22/2200 UTC, peaking at 50.2 kts at 22/1400 UTC. The minimum SLP
during this period was 970.4 hPa at 22/2100 UTC.
Another period of gale-force winds had commenced by 23/1300 UTC and
continued through 23/2000 UTC, peaking at 62.2 kts with a minimum
SLP of 965.0 hPa at 23/1800 UTC. The strong winds during both these
periods were from the NE and NNE. After several hours of relatively
light winds, the winds picked up again and approached gale force
from the W and WSW around 24/1200 UTC.
(Chunliang's Note: This part of the report was distilled, translated
and edited from the raw data on the official web pages of the Central
Weather Bureau of Taiwan (Chinese version). The URL is:
http://www.cwb.gov.tw/V4/index.htm>
(3) Chunliang has also sent some observations from Japanese stations.
The only significant 24-hourly rainfall amount was from Okinawa.
Station Tarama (JMA 93061, 24.67N, 124.70E, Alt 16 m) recorded
342 mm on 24 April, although I am not sure of the exact applicable
time period.
Only two stations were listed which experienced 10-min avg maximum
sustained winds exceeding gale force. Station Ishigakijima on
Okinawa (WMO 47918, 24.33N, 124.17W, Alt 6 m) recorded a peak MSW
of 37.5 kts from the south at 1000 UTC on 24 April with a minimum SLP
of 996.9 hPa. Tarama (JMA 93061) measured SSE winds of 38.9 kts at
24/1200 UTC. Aburatsu, Miyazaki (WMO 47835, 31.57N, 131.42E, Alt 3m)
recorded SSW winds of 32 kts at 24/1700 UTC.
Several stations recorded peak gusts exceeding gale force with a few
exceeding storm force and one of hurricane intensity. Peak gusts
exceeding 48 kts (24.6 m/sec) include:
Ishigakijima, Okinawa WMO 47918 Alt 6 m Peak Gust = 76.2 kts
Akune, Kagoshima WMO 47823 Alt 40 m Peak Gust = 58.1 kts
Makurazaki, Kagoshima WMO 47831 Alt 30 m Peak Gust = 51.7 kts
Tanegashima, Kagoshima WMO 47837 Alt 17 m Peak Gust = 49.4 kts
Yakushima, Kagoshima WMO 47836 Alt 36 m Peak Gust = 53.1 kts
Aburatsu, Miyazaki WMO 47835 Alt 3 m Peak Gust = 48.0 kts
(Chunliang's Note: This part of the report was distilled, translated
and edited from the raw data on the official web pages of the JMA
(Japanese version). The URL is:
http://www.jma.go.jp/>
D. Damage and Casualties
------------------------
Kujira was the first named April tropical cyclone of the past 25 years
that affected Taiwan, i.e., required local warnings released by CWB. The
only four named April storms that CWB issued warnings on since 1958 have
been Karen (1960), Violet (1967), Olive (1978) and Kujira (2003).
Like its three predecessors, Kujira did not bring significant damage
to the territory. The local media did not report any casualties, though
the airports in Lan Yu and Green Island had to be closed for two or three
days due to the strong winds.
(Report written by Gary Padgett and Kevin Boyle with significant
contributions by Huang Chunliang)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for April: No tropical cyclones
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for April: 1 subtropical cyclone
Southwest Indian Ocean Tropical Activity for April
--------------------------------------------------
No officially recognized tropical cyclones formed during April in the
Southwest Indian Ocean; however, there was one named subtropical system
(Luma) which attained cyclone (hurricane) intensity. MFR issued warnings
on Subtropical Depression Luma, but none were issued by JTWC. Several
meteorologists in the tropical cyclone community were of the opinion that
Luma did attain nominal tropical characteristics. The following report
on Luma was largely written by Dr. Karl Hoarau of Cergy-Pontoise
University in Paris--a special thanks to Karl for writing the summary.
SUBTROPICAL CYCLONE LUMA
(MFR-15)
6 - 12 April
--------------------------------------------
Luma: contributed by Swaziland
A. Introduction
---------------
Subtropical Cyclone Luma was an unusual system which formed in the
southern Mozambique Channel, remaining in the same general area off the
southwestern coast of Madagascar for several days as a weak system, then
accelerating very rapidly off to the east-southeast as it intensified.
The system was referred to as a "subtropical depression" in warnings
from the La Reunion TCWC (MFR), but since it did attain cyclone (i.e.,
hurricane) intensity, I have referred to it as a "subtropical cyclone"
in the title line above. (In most regions of the world, the term
"depression" signifies a system with peak winds less than gale force.)
During the time Luma was active, there was a goodly amount of e-mail
traffic from meteorologists around the world discussing the nature of the
system. Several were of the opinion that Luma had completely made the
transition into a tropical system by 10 April, and SAB assigned Dvorak
tropical T-numbers (as opposed to subtropical ST ratings) consistently
from 0830 UTC on the 8th until the system became fully extratropical
on the 11th, reaching a peak of T4.5/4.5 (77 kts) at 11/0830 UTC.
MFR initiated warnings on the intensifying disturbance at 1200 UTC
on 10 April, estimating the MSW at 40 kts (10-min avg). Responsibility
for naming systems west of 55E rests with the Meteorological Services
of Madagascar, and the storm was apparently not named until 0600 UTC
on 11 April. By this time winds were at hurricane intensity and Luma
was racing east-southeastward at 40 kts.
JTWC mentioned the disturbance in their STWO's on 8 and 9 April,
assigning a fair development potential at 08/1300 UTC, and remarking
that the LLCC was developing tropical characteristics. However, the
potential for development was downgraded to poor at 09/1800 UTC, and the
remarks indicated that in the opinion of the analyst, the system was
beginning to show signs of extratropical transition. JTWC did not issue
any warnings on Luma and the system was not mentioned in the STWO's
after 10/1800 UTC.
Due to the interest in this system concerning its classification, I
asked Dr. Karl Hoarau to perform an analysis of Luma and to give me his
opinion. I also asked him to prepare a track for the pre-warning
portion of Luma's history. Karl responded by preparing a track for the
entire lifecycle of the storm as well as by writing a rather detailed
report based on his personal analysis.
I have included Karl's report below with only minor editing. Karl
was of the opinion that Luma had indeed become a predominantly tropical
cyclone by 0000 UTC on 10 April, reaching a peak intensity of 75 kts
(1-min avg) at 0600 UTC on the 11th. (This agrees very well with MFR's
estimated peak 10-min avg MSW of 65 kts.) I have chosen to let Karl's
terminology (i.e., Tropical Cyclone Luma) stand as he wrote it, but this
should not be understood as implying any criticism of MFR. Nature
produces a spectrum of cyclone types, and the boundaries between the
various classes are not sharply-defined, so there is an inherent degree
of subjectivity involved in deciding whether to classify a particular
system as a tropical or subtropical cyclone. The good thing is that
warnings were issued, warning mariners of a small, intense marine
cyclone. In the author's personal opinion, having a name assigned was
the important thing to grab attention, indicating that Luma posed a
significant threat to shipping interests, whether it was called
subtropical or tropical.
The remainder of this summary consists of Karl's report--a special
thanks to Karl for preparing it and sending it to me.
B. Synoptic History
-------------------
On the afternoon of 6 April, a low-level circulation center with
associated curved bands formed near the southwestern coast of Madagascar
near 25.4S, 41.5E, or roughly 150 nm southwest of Tulear. Through the
morning of the 9th the LLCC was completely or partly-exposed and the
convection did not produce a warming in the upper troposphere near the
center of the disturbance. Moreover, QuikScat data indicated maximum
sustained winds of 30 knots on the 8th at 1800 UTC, but these winds
were not located near the center. These observations suggest that the
system was a subtropical depression during this phase.
After initially tracking in a northwesterly direction under the
influence of the subtropical ridge, the disturbance completed a loop
early on 8th. Then, the depression moved south-southwestward at 5 knots
before turning east-southeastward at an increased rate of speed which
reached 32 knots on the 11th south of 30S. Meanwhile, the depression
became a subtropical storm on the 9th around 1800 UTC, based on QuikScat
data showing winds of 35 knots. A transition to a more tropical-like
system began around this time as new deep convection built over the LLCC
and began to produce a warming in the upper troposphere. By 0000 UTC
on 10 April the subtropical storm had become a tropical storm of 45 knots
located approximately 200 nm south of Tulear.
The storm intensified further and the 37 GHz image from the 10/0939
UTC TRMM pass showed an eye while the 85 GHz image indicated the
formation of a partial eyewall. Luma was estimated to have reached
cyclone (hurricane) intensity of 65 knots by 0000 UTC on the 11th and
the maximum intensity of 75 knots was reached six hours later. The
storm by this time was located over 600 nm south-southwest of Reunion
Island. This tropical cyclone displayed an Off White eye (-4.6C at
0500 UTC) embedded in a Medium Gray ring of convection in enhanced infra-
red imagery. The coldest cloud top temperature was -62 C. The Dvorak
analysis gave a T-number of 4.5 from 0100 until 0900 UTC on the 11th.
The 85 GHz image from the 11/0514 UTC DMSP F15 pass showed a small eye
inside a closed eyewall. The intensification of Luma occurred in a
weakly sheared environment. The CIMSS charts indicated west-
southwesterly winds of 40 knots between 350 hPa and 150 hPa. As the
winds in the low and mid-troposphere were around 30 knots, the relative
vertical wind shear was about 10 knots. After 0900 UTC on the 11th,
Luma began to weaken with the increasing shear and at 1200 UTC, the eye
was no longer visible. Finally, Luma merged with a cold front during
the night of 11 April. The final warning from MFR at 12/0000 UTC placed
the extratropical gale center over 1200 nm south-southeast of Rodrigues
Island.
C. On the Origin and Character of This Storm
--------------------------------------------
As mentioned above, there is no doubt about the subtropical origin of
Luma. And on 7 April at 1200 UTC, the depression had a huge cyclonic
circulation between 35E-50E and 20S-35S. But during the evening of the
9th, the circulation shrank while the convection become deeper and the
overall pattern looked more tropical. Moreover, Derrick Herndon from the
CIMSS pointed out that the AMSU data showed that Luma had undergone a
transition into a tropical system. Derrick stated that the lowest Sea
Level Pressure deduced from the AMSU data was 980 hPa on the morning of
the 11th. As Tropical Cyclone Luma had higher-than-normal surrounding
pressures (1010-1012 hPa instead of the usual 1006-1008 hPa ), the SLP
of 980 hPa matched well-enough with the intensity of 75 kts analysed
from the EIR satellite pictures. In fact, on the 11th at 0600 UTC when
Luma was estimated to have reached its maximum intensity, the cyclone
near 32.4S, 55.9E was located between two subtropical ridges, the first
one (1020 hPa) situated around 33S, 35E, and the second one (1022 hPa)
around 30S, 75E.
Before the evening of the 11th, Tropical Cyclone Luma was not
associated with a cold front. The band of clouds north of the center
was a spiral band and could not be taken as a cold front. These clouds
passed over the southern tip of Madagascar, and the Fort Dauphin (WMO
67161) and Tulear (WMO 67197) stations did not indicate any variations
in the dew point. All the data reported here shows that Luma was a
tropical cyclone which reached its maximum intensity of 75 kts over a
SST of 24.5-25 C. But this is not an exceptional feature in other
basins, especially in the Atlantic. A remarkable feature is that Luma
was in an intensifying stage south of 30S. And it is quite unusual, too,
that a cyclone reached an intensity of T4.5 at that latitude in the
Southern Hemisphere.
D. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from this
marine cyclone.
(Report written by Karl Hoarau with introduction by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for April: 1 severe tropical cyclone (hurricane)
Northwest Australia/Southeast Indian Ocean
Tropical Activity for April
------------------------------------------
During almost every tropical cyclone season, waters off the Western
Australian coast in the Timor Sea will see at least one very intense
tropical cyclone. The 2002/2003 season was no exception, although it
was getting late in the season before intense Tropical Cyclone Inigo
made its appearance. Fortunately for Western Australia, Inigo weakened
to below cyclone levels before finally limping ashore in Australia's
great western state. Thus, the 2002/2003 season was the first since the
1997/1998 season which did not see an intense tropical cyclone make land-
fall somewhere along the Western Australian coastline. Intense cyclones
making landfall in Western Australia during the past four seasons were:
1998-1999 Thelma, Vance
1999-2000 John, Rosita
2000-2001 Sam
2001-2002 Chris
However, torrential rains during Inigo's formative stages brought deadly
and destructive flooding to some of the Indonesian islands.
SEVERE TROPICAL CYCLONE INIGO
(TC-26S)
1 - 8 April
-------------------------------------------------
A. Storm Origins
----------------
The daily Tropical Weather Outlook issued by the Darwin TCWC on
27 March noted that a weak 1008-mb tropical LOW was situated near the
southern coast of Irian Jaya. The next day the LOW was located in the
Arafura Sea north of the Northern Territory and moving westward. The
potential for development into a tropical cyclone was assessed as
moderate after a couple of days. By the 29th the LOW was in the Banda
Sea north of Jamdena, still moving westward. The STWO issued by JTWC
at 1800 UTC noted that scattered deep convection was present around the
weak LLCC, although somewhat disorganized. An upper-air analysis
indicated favorable outflow aloft.
On 30 March the disturbance was northeast of East Timor and had turned
to a southwesterly track. JTWC upgraded the development potential to
fair--organization was improving and the LLCC was tracking toward a
region of improved upper-level outflow. The southwesterly motion
continued on the 31st with the LOW crossing the Indonesian islands in
the vicinity of western Timor and eastern Flores. At 1400 UTC JTWC
issued a TCFA. Increased spiral banding was evident as the system
approached an upper-level ridge axis with weak vertical shear and
enhanced poleward outflow.
On 1 April the tropical LOW moved across Sumba Island. The first
gale warning from Perth at 1000 UTC placed the center approximately
475 nm north-northwest of Broome, or over southeastern Sumba Island.
JTWC issued their first warning on TC-26S at 1200 UTC. The MSW was
estimated at 35 kts (1-min avg), and the system was then moving west-
southwestward at 7 kts as it was steered by a low to mid-level ridge
to the south.
B. Track and Intensity History
------------------------------
Perth upgraded the LOW to Tropical Cyclone Inigo at 0000 UTC on
2 April. Inigo's center was located about 450 nm northwest of Broome,
or 60 nm southwest of Sumba Island. The intensity was estimated at
40 kts, and JTWC's 1-min avg MSW was 45 kts. Inigo was moving south-
westward at 6 kts and steadily becoming better organized. By 1200 UTC
the cyclone had reached a position about 115 nm southwest of Sumba
Island with both Perth and JTWC estimating the MSW at 55 kts. A SSM/I
pass at 02/2334 UTC indicated that Inigo had developed a 25-nm diameter
eye, and CI estimates had reached 77 and 90 kts. JTWC upped the MSW
(1-min avg) to 80 kts at 03/0000 UTC, and in their next warning at
0400 UTC, Perth increased the intensity to 70 kts, thus upgrading Inigo
to severe tropical cyclone (hurricane) status. The cyclone at this time
was located almost 200 nm southwest of Sumba Island.
Severe Tropical Cyclone Inigo continued moving slowly toward the
west-southwest on 3 April while rapidly intensifying. JTWC upped the
MSW (1-min avg) to 115 kts at 1200 UTC, and at 2200 UTC Inigo reached
its peak intensity of 120 kts (10-min avg) as estimated by the Perth
TCWC. JTWC increased the MSW to their peak value of 140 kts at 0000 UTC
on the 4th. In the 0400 UTC warning Perth dropped the estimated CP to
the very low value of 900 mb. The very intense Inigo was then located
approximately 550 nm north of Onslow, moving slowly in a general south-
westerly direction. Gales extended outward from the center about
130 nm while the radius of 50-kt winds was estimated at 65 nm. Around
0000 UTC on 5 April Inigo sported an 18-nm diameter symmetrical eye.
Inigo maintained its peak intensity of 120 kts through 05/1000 UTC, at
which time Perth lowered the MSW to 110 kts. (JTWC had begun decreasing
the intensity at 05/0000 UTC and was estimating the MSW (1-min avg) to be
120 kts at 0600 UTC.) The cyclone was forecast to recurve into a weak-
ness in the subtropical ridge to the south brought about by a passing
mid-latitude trough. By 1200 UTC the eye had become cloud-filled, and
the 1800 UTC JTWC warning noted that the eye had become a banding-type
eye. The storm was by then moving slowly southward, and Inigo reached
the westernmost point of its trajectory around 2200 UTC when it was
centered approximately 425 nm north-northwest of Onslow. Perth and JTWC
were estimating the intensity at 90 and 100 kts, respectively, at this
juncture.
On 6 April Tropical Cyclone Inigo moved very slowly southward and
gradually turned to a south-southeasterly track as it slowly weakened.
At 1800 UTC the storm was located about 350 nm north of Learmonth, moving
south-southeastward at 8 kts, and the winds had come down to around
80 kts. Continued weakening was forecast due to dry air entrainment and
increasing vertical shear. Visible imagery around 0600 UTC on 7 April
revealed that the deep convection was sheared east of the LLCC. Both
Perth and JTWC were estimating the intensity at 65 kts at this time.
By 07/1200 UTC Inigo's center was located about 250 nm west-northwest of
Port Hedland and moving southeastward at 11 kts. At 1600 UTC Inigo was
located roughly 200 nm west-northwest of Port Hedland and the MSW had
further dropped to 55 kts. Deep convection continued to accelerate
southeastward ahead of the LLCC in the face of increasing shear.
Tropical Cyclone Inigo collapsed rapidly as it neared the Western
Australian coastline. Satellite imagery around 08/0000 UTC revealed
a fully-exposed LLCC. Perth issued their final gale warning at 0400 UTC
with the MSW estimated at 40 kts. The final public advice was issued
one hour later, downgrading the system to an ex-cyclone. At 0600 UTC
Inigo was just offshore approximately 40 nm east of Barrow Island and
ready to make landfall about 50 nm west of Karratha. JTWC estimated
the 1-min avg MSW at landfall to be 35 kts, which would correspond to a
10-min avg wind of around 30 kts. By 1200 UTC the system was inland and
dissipating as the remnant LOW scooted southeastward at 18 kts.
Barrow Island recorded 50 mm of rainfall in the 24 hours ending at
08/0100 UTC, and Yalleen and Yarraloola each measured 30 mm during the
same period. Mardie recorded 159 mm in the 24 hours ending at 0100 UTC
on 9 April with all of this falling during a 6-hour period. (These
rainfall observations were sent by Matthew Saxby--a thanks to Matthew
for passing them along.)
C. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Inigo after it
had been named as a tropical cyclone--it had all but collapsed prior to
making landfall in Western Australia. However, as the tropical LOW
precursor of Inigo crossed the Indonesian islands, torrential rains fell
which triggered destructive landslides and flooding. At least 50 persons
perished: 10 in the East Flores district, 31 in the Ende district on
Flores Island, and 9 in the Sikka district on Besar Island. As of
8 April more than 100 persons were still reported as missing.
In the Sikka district the total losses were estimated at approximately
$3.3 million (USD), of which $664,000 (USD) were agricultural losses.
Over 1300 homes were destroyed with 4800 damaged. The island's infra-
structure was hard hit with significant damage to water irrigation
systems, roads and bridges. In the East Flores district, 121 homes were
destroyed with approximately 500 damaged. Roads and electrical power
lines were damaged as well as sanitation and drainage pipe systems. In
the Ende district considerable damage was sustained to roads, buildings
and schools. In addition, many crops and cattle were swept away.
Additional reports on the Indonesian landslides can be found at the
following URL:
http://www.reliefweb.int/w/rwb.nsf/vLND>
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for April: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for April: 1 tropical cyclone of gale intensity
South Pacific Tropical Activity for April
-----------------------------------------
Three tropical disturbances were assigned numbers by the Nadi TCWC
during April. Two of these were weak and never accorded tropical
depression status. Tropical Disturbance 14F was located near the islands
of Espiritu Santo and Malekula in northwestern Vanuatu around 0600 UTC
on 7 April. The LOW was embedded in a monsoon trough, and although at
the time was located in a weakly-sheared environment, it was forecast to
track southeastward into a region of stronger vertical shear. Twenty-
four hours later the system had trekked fairly quickly southeastward and
was located near Matthew Island east of New Caledonia. Deep convection
was displaced east of the center and SSTs were cooling.
Tropical Disturbance 15F was a weak system which was mentioned in the
Tropical Disturbance Summaries from Nadi only on 13 April. This system
developed southwest of Samoa and moved southward at the same time that
Tropical Cyclone Fili (16F) was developing to the northwest. Convection
associated with 15F was poorly-organized and located several degrees to
the north of the LLCC. The only named cyclone was Fili, which was a very
short-lived system. A short report on Fili follows.
TROPICAL CYCLONE FILI
(TD-16F / TC-27P)
13 - 15 April
-----------------------------------------
The great South Pacific tropical cyclone season of 2002/2003, which
produced a record six intense tropical cyclones (1-min avg MSW 100 kts
or greater), ended on a rather quiet note (barring the very unlikely
development of a June tropical cyclone). A STWO issued by JTWC at
0000 UTC on 13 April noted the development of an area of convection
which had developed approximately 200 nm northeast of Fiji. There
were some indications of cyclonic turning of the convection, and an
upper-level analysis indicated favorable divergence aloft but with
marginal vertical shear over the region. Nadi also began mentioning
the disturbance in their tropical disturbance summaries on the 13th.
(Editor's Note: Regarding the first sentence in the above paragraph--
the unlikely development of a June tropical cyclone did happen with
the formation of Tropical Cyclone Gina during the first week in June.
Gina became a fairly strong hurricane, and brings the 2002/2003 total
for the South Pacific basin to 10 tropical cyclones (including one
visitor from the Australian Region) with 7 of hurricane intensity.)
JTWC upgraded the potential for development to fair at 13/1600 UTC,
and a TCFA was issued at 2330 UTC. Convection had continued to organize,
and a TUTT cell to the southwest was helping to enhance the upper-level
divergence. At 14/0000 UTC Fiji classified the disturbance as Tropical
Depression 16F and noted that some peripheral gales were occurring with
the system. At 0600 UTC JTWC issued their first and only warning on
TC-27P, locating the center approximately 360 nm east-northeast of
Suva, Fiji, and moving east-southeastward at 17 kts. It was expected
that the system would merge with an upper-level LOW to the southwest
and become extratropical during the next 12 hours.
Convective organization, however, improved overnight, and by 1200 UTC
SAB was assigning a Dvorak rating of T3.0/3.0, implying winds of 45 kts.
Nadi named the system Tropical Cyclone Fili at 1800 UTC, located roughly
200 nm east-northeast of Tongatabu and moving southeastward at 20 kts.
Convection was holding steady with the main band wrapping around the
LLCC. At 15/0000 UTC the Nadi TCWC also rated the cyclone as T3.0 and
upped the MSW (10-min avg) to 45 kts. Fili was by this time accelerating
into strengthening northwesterly shear downwind of an upper-level trough
and racing southward at 35 kts.
The 15/0000 UTC warning was the final one from Fiji as the system
entered Wellington's AOR shortly afterward. At 15/0600 UTC the final
tropical cyclone warning on Fili, issued by the Wellington office,
placed the center approximately 500 nm southeast of Tongatabu and
moving south-southwestward at 30 kts. The intensity was increased to
50 kts, possibly to take into account the rapid translational speed.
By 1200 UTC Fili had merged with a cold front and was a weakening
extratropical gale center.
No damage or casualties are known to have resulted from Tropical
Cyclone Fili.
(Report written by Gary Padgett)
*************************************************************************
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> OR http://64.235.42.210>
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 2001 (2000-2001 season for the Southern
Hemisphere). ATCRs for earlier years are available also. Recently
added was the report for the Southern Hemisphere 2001-2002 season.
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, preliminary 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
John Wallace (Eastern North Pacific, North Indian Ocean, Western
Gulf of Mexico)
E-mail: [email protected]
Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South
China Sea)
E-mail: [email protected]
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: [email protected]
*************************************************************************
*************************************************************************
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Document: summ0304.htm
Updated: 27th December 2006 |
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