[Index]
Monthly Global Tropical Cyclone Summary February 1998
[Summaries and Track Data] [Prepared by Gary Padgett]
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Monthly Global Tropical Cyclone Summary February 1998 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
FEBRUARY, 1998
(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.)
HIGHLIGHTS
--> A fairly active month but storms generally remain at sea
--> South Indian Ocean comes alive
***********************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for February: No tropical cyclones
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NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for February: No tropical cyclones
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NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for February: No tropical cyclones
***********************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for February: No tropical cyclones
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SOUTH INDIAN OCEAN (SIO) - South Indian Ocean West of Longitude 90E
Activity for February: 4 tropical cyclones of gale intensity **
1 tropical cyclone of hurricane intensity
** - two of these classified only by JTWC, Guam
NOTE: The only sources of information on South Indian cyclones I have
available for the time being are the warnings issued by JTWC. All the
winds reported in the narrative are 1-min average maximum sustained
winds.
Tropical Cyclone Anacelle (TC-20S) 8-14 February
--------------------------------------------------
Although JTWC had previously classified two tropical cyclones in
the South Indian Ocean basin (01-S in July and 13-S in January),
Anacelle was the first actual named cyclone in the basin this season.
The first JTWC warning on the cyclone was issued at 0600 UTC on 8 Feb
with the center about 275 nm northeast of St. Brandon Island. The
storm intensified slowly for a couple of days as it drifted generally
in a westerly direction. On the 9th Anacelle turned to a southerly
course, and its forward motion increased as it steadily strengthened.
At 10/1200 UTC Anacelle passed very near St. Brandon with maximum
sustained winds estimated at 90 kts. Continuing to move to the south,
Anacelle reached a peak intensity of 115 kts at 1200 UTC on 11 Feb
when centered about 100 nm east-southeast of Mauritius. After
passing Mauritius the cyclone turned to the southeast and began to
accelerate toward mid-latitudes. Winds had dropped below hurricane
force by 13/1200 UTC, and the cyclone had become extratropical 24 hrs
later near 41S, 84E.
I have been unsuccessful in obtaining any reports from any of the
islands in the South Indian Ocean that may have been affected by
Anacelle, especially St. Brandon and Mauritius. If anyone has any
information about the effects of this cyclone, including damage and
casualty figures as well as meteorological reports, I would be very
grateful if they would send the information to me so that I can
include it in a future summary.
Tropical Cyclone 21-S 9-10 February
-------------------------------------
A tropical disturbance drifted from near the coast of Mozambique to
near the southern tip of Madagascar in early February. Early on 9 Feb
scatterometer data indicated an area of 35-kt winds within 60 nm of the
low-level circulation center. Therefore, JTWC initiated warnings on
Tropical Cyclone 21-S at 0600 UTC on 9 Feb. The system was located
at this time about 225 nm south of Tulear on the southwest coast of
Madagascar. TC-21S formed in a high vertical shear environment and
did not strengthen any further. The weak cyclone moved off to the
south-southeast and had weakened to a depression by 0000 UTC, 10 Feb.
Tropical Cyclone Beltane (TC-23S) 17-18 February
--------------------------------------------------
The active pattern in the Mozambique Channel continued into mid-
February as another tropical disturbance began to strengthen on the
16th. Convection began to organize very rapidly, transforming the
system from a relatively weak disturbance into a significant tropical
cyclone. By 0600 UTC the developing cyclone was located about 150 nm
northwest of Tulear, Madagascar, with 35-kt winds. Beltane moved
south-southeast to near the southern tip of Madagascar by 17/1800 UTC
with winds reaching a peak intensity of 40 kts late on the 16th. By
early on 18 Feb all the deep convection had been sheared from near the
center and the weakening low-level circulation began to move back
toward the northwest. The last JTWC warning, issued at 18/1800 UTC,
placed the weakening cyclone in the Mozambique Channel about 100 nm
west-southwest of its point of origin.
Tropical Cyclone Victor/Cindy (TC-22S) 10-19 February
-------------------------------------------------------
The weakening Tropical Cyclone Victor crossed 90E into the Mauritius
area of warning responsibility shortly after 0000 UTC on 16 Feb. In
accordance with a long-standing practice the system was re-named Cindy.
(See the portion of this summary covering the Australian Region for
information on the earlier portion of this cyclone's history. Victor
was actually a re-development of the extremely long-lived Tropical
Cyclone Katrina, which roamed the Coral Sea for over three weeks in
January.)
Tropical Cyclone Cindy was a minimal tropical cyclone with winds of
only 35 kts when it was re-named about 1800 nm east of Mauritius. The
system continued on a general westerly track for a couple of days, and
then turned to a southerly course and accelerated. The storm had
merged with a front and lost tropical characteristics by 19/0000 UTC
about 1150 nm east-southeast of La Reunion, more than 50 days after
the pre-Katrina tropical LOW was first analyzed.
Tropical Cyclone 24-S 16-19 February
--------------------------------------
The first warning on Tropical Cyclone 24-S was issued by JTWC at
1200 UTC on 16 Feb, locating the center about 500 nm east of La
Reunion with 35-kt winds. The system initially moved to the south-
southwest, turning to the southeast after 1200 UTC on the 17th, and
finally accelerating eastward on 18 Feb. Vertical shear and cooler sea
surface temperatures prevented this system from intensifying further
as a tropical cyclone. Winds were increased to 45 kts in the warning
issued at 18/1200 UTC to account for the tendency of systems undergoing
extratropical transition to intensify due to faster forward motion.
The final warning at 0000 UTC on 19 Feb, which located the center
about 1000 nm east-southeast of La Reunion, indicated that the cyclone
was expected to merge with a cold front during the forecast period.
***********************************************************************
AUSTRALIAN REGION (AUS) - From Longitude 90E Eastward to Longitude 160E
Activity for February: 1 weakening tropical depression
1 tropical cyclone of gale intensity
1 tropical cyclone of hurricane intensity
Much of the information presented below on Tropical Cyclones Victor
and May was taken directly from the Darwin Tropical Diagnostic State-
ment for February. A special thanks to Sam Cleland for sending it
to me. Unless otherwise noted, references to sustained winds imply
a 10-minute average wind.
Tropical Cyclone Les (TC-14P) 23 January-2 February
-----------------------------------------------------
As the month of February opened, former Tropical Cyclone Les was a
weakening depression overland in Western Australia about 65 nm south-
southeast of Broome. The Perth TCWC issued the last advice at 0000
UTC on 1 Feb but JTWC kept the system at minimal gale intensity for
another day, primarily because of a very well-organized cloud pattern
which, over water at least, would have suggested 35-kt winds (1-min
avg). However, by 02/0000 UTC Guam issued the last warning, downgrading
the system to a weakening depression over the Great Sandy Desert about
200 nm south-southeast of Broome.
Back in January extremely heavy rainfall related to Tropical Cyclone
Les had led to disastrous flooding in the Northern Territory near the
town of Katherine. For more information on this, see the summary for
January, 1998.
Tropical Cyclone Victor (TC-22S) 10-16 February
-------------------------------------------------
Tropical Cyclone Victor was a re-development of the residual LOW
which had been former Tropical Cyclone Katrina in January. The low-
pressure area that developed into Katrina was first analyzed on Darwin
RSMC charts in the southwest Pacific on 31 Dec. It was named Katrina
on 2 Jan and remained at tropical cyclone intensity for more than three
weeks, wandering along on a complicated, looping track. For a
description of Katrina's life, see the summary for January, 1998.
After weakening below tropical cyclone intensity, the residual LOW
remained identifiable as it passed over the northern Cape York
Peninsula and across the northern extremity of the Gulf of Carpentaria.
It crossed the Top End of the Northern Territory, then moved into the
northern Kimberley region of Western Australia, and finally into the
Indian Ocean. On 8 Feb a surface observation from Troughton Island
reported winds of 20-27 kts with gusts to 35 kts and a pressure of
1009-1010 mb. Once the system had cleared the coast and was over the
open waters its convection and vertical structure as well as its upper
outflow improved, and it was named Victor by the Perth TCWC on 10 Feb
at 1200 UTC. The center was then located about 300 nm north of Port
Hedland, Western Australia. Also on the 10th a warning from JTWC
alluded to a ship report of 40-kt winds, but the time and location
weren't given.
Victor continued to strengthen for a couple of days, reaching a peak
intensity of 70 kts by 13/0600 UTC. This is a 10-min average wind,
and Guam's maximum 1-min average wind of 90 kts is in reasonable
agreement--slightly on the high side. After this the cyclone was
approached by an upper mid-latitude trough. Outflow diminished and
the system weakened quickly. By 0000 UTC on the 15th most of the
deep convection had dissipated, revealing an extremely well-wrapped
low-level cloud center. Victor maintained an almost straight-line
west-southwest track from the Gulf of Carpentaria into the central
South Indian Ocean. Shortly after 0000 UTC on 16 Feb the weakening
minimal cyclone crossed 90E into the Mauritius/La Reunion area of
warning responsibility and was renamed Cindy. See the portion of
this summary covering the South Indian Ocean basin for the final
chapter in the life of what can be referred to as Tropical Cyclone
Katrina/Victor/Cindy.
Tropical Cyclone May (TC-25P) 25-26 February
----------------------------------------------
A low-pressure system was observed in the Arafura Sea near the Gulf
of Carpentaria on 21 Feb. A surge in the northwesterly monsoon flow
into this system heralded the re-emergence of active monsoon conditions
over northern Australia. Initially, the system was not well organized
and drifted into the Gulf of Carpentaria over the next few days. A
HIGH that persisted in the Tasman Sea from the 23rd to the 25th
increased low-level southeasterly flow south of the system, thereby
increasing its vorticity. The first advice on the developing LOW was
issued at 0300 UTC on 25 Feb, locating the center roughly 150 nm east-
southeast of Groote Eylandt.
Outflow became better established and May was named at 1800 UTC.
Northwesterly flow increased and May followed a slow southward track,
making landfall near Mornington Island on the 26th with maximum
sustained winds of 40 kts and an estimated central pressure of 990
mb. The mid-level circulation of May was slow-moving after this time
and did later move back over the Gulf but never became re-organized
sufficiently to regain tropical cyclone intensity. Information
obtained by the author at website http://nic.fb4.noaa.gov/products/
analysis_monitoring/GLOB_CLIM/current.html> indicated that Tropical
Cyclone May produced rainfall measuring from 100-350 mm on the Cape
York Peninsula, primarily in the western sections.
***********************************************************************
SOUTHWEST PACIFIC (SWP) - South Pacific Ocean East of Longitude 160E
Activity for February: 3 tropical depressions
1 tropical cyclone of gale intensity
2 tropical cyclones of storm intensity
A special thanks to Mark Kersemakers of the Fiji Tropical Cyclone
Warning Centre at Nadi for sending along some information on this
month's cyclones. Unless otherwise stated, any references to
sustained winds imply a 10-minute average wind.
Tropical Cyclone Ursula (TC-17P) 29 January-2 February
--------------------------------------------------------
Tropical Cyclone Ursula had begun on 29 Jan to the north of Tahiti
and had moved southeastward through the Tuamotu Archipelago on 30-31
Jan. On 31 Jan Ursula had reached a peak intensity of 55 kts and had
accelerated to the southeast. At 0000 UTC on 1 Feb the cyclone was
located about 500 nm west-northwest of Pitcairn Island and was moving
rapidly southeastward. Warning responsibility was handed to the
Wellington office after Ursula crossed the 25th parallel at 01/0600
UTC.
By 0000 UTC on 2 Feb Ursula was located about 300 nm south of
Pitcairn and was beginning to lose tropical characteristics. The storm
was declared extratropical six hours later and the last warning was
issued at 02/1200 UTC, locating the cyclone about 700 nm southeast of
Pitcairn and roughly the same distance southwest of Easter Island.
Very few tropical cyclones move as far east in the South Pacific as
Tropical Cyclone Ursula. To date I have received no reports of any
damage or casualties caused by Ursula. If any do become available
I will include them in a future summary.
Tropical Cyclone Veli (TC-18P) 31 January-3 February
------------------------------------------------------
Tropical Cyclone Veli came right on the heels of Ursula and passed
through the same area as the former cyclone. A tropical depression
had formed on 31 Jan about 250 nm east-southeast of Manihiki Atoll in
the Northern Cooks. The system began moving east-southeastward and
the first warning on Veli was issued by the Nadi Warning Centre at
0000 UTC on 1 Feb, placing the center about 300 nm northwest of Tahiti
with 35-kt winds. Veli continued moving in a general southeasterly
direction, passing about 125 nm north-northeast of Tahiti around 1200
UTC on 1 Feb. Peak intensity of 55 kts was first attained at 0000
UTC on 2 Feb when the cyclone was located about 200 nm east-southeast
of Tahiti. At 02/1200 UTC station WMO 91945 (19.8S, 145.0W) reported
a wind of 20 kts and a pressure of 998 mb. Veli at this time was
centered about 40 nm to the west-northwest. At 2100 UTC an NPMOC
warning mentioned that scatterometer data indicated an intensity of
45 kts.
Like Ursula, Tropical Cyclone Veli passed through the Tuamotus,
keeping to the southwest of and parallel to the main chain of islands.
However, unlike the earlier cyclone, Veli did not get caught up in the
westerlies and race off to the southeast. The system slowed its
forward motion when located near 144W and drifted slowly southward
while weakening. The last warning at 03/1800 UTC, downgrading Veli to
a depression, placed the center about 500 nm southeast of Tahiti.
As is the case with Ursula, to date I have received no reports of
any damage of casualties resulting from Tropical Cyclone Veli. If any
do become available they will be included in a future summary.
Tropical Cyclone Wes (TC-19P) 31 January-5 February
-----------------------------------------------------
The depression from which Tropical Cyclone Wes developed was first
located about 125 nm northwest of Apia, Western Samoa, at 0600 UTC on
31 Jan. The depression drifted slowly eastward and strengthened,
becoming Tropical Cyclone Wes at 0600 UTC on 1 Feb about 200 nm north-
east of Pago Pago, American Samoa. Wes initially continued moving on
an easterly course, passing about 50 nm south of Nassau Island at
01/1800 UTC. At 0600 UTC on 2 Feb the cyclone was re-located to a
position very near Suwarrow Atoll. Maximum sustained winds had by
this time increased to their peak value of 45 kts.
After this point Wes began to move on a slow course generally in a
southeasterly direction. At 03/0600 UTC the system was centered about
225 nm northeast of Palmerston Island. By 0000 UTC on 4 Feb the
weakening cyclone had become quasi-stationary near the Southern Cooks
roughly 100 nm northeast of Aitutaki Atoll. Wes was downgraded to a
tropical depression at 1200 UTC on 4 Feb and the last warning was
issued at 05/0000 UTC.
Mark Kersemakers of the Fiji TCWC has informed me that there is a
distinct possibility that Wes was a re-development of Tropical Cyclone
Tui which passed over Samoa in late January. After Tui had weakened,
the remnants remained in the general region of Samoa. Some other weak
low-pressure areas developed and it became difficult to keep track
of the Tui remnants. Because of the uncertainty it was decided to
treat Wes as a separate cyclone.
Tropical Depression 11-15 February
------------------------------------
A developing disturbance was classified as a tropical depression at
0000 UTC on 11 Feb about 100 nm north-northwest of Suwarrow Atoll in
the Northern Cooks. Over the next couple of days this system drifted
very, very slowly westward. By 13/1200 UTC the depression was only
190 nm southwest of its initial position. At 1800 UTC the center was
re-located about 70 nm to the east--about 100 nm south-southeast of
Nassau Island. The system drifted perhaps very slightly eastward but
remained in the same general area for another two days. The last
disturbance advisory, at 0600 UTC on 15 Feb, placed the depression
about 60 nm east of Suwarrow Atoll or about 125 nm southeast of its
point of origin.
From 1800 UTC on 3 Feb through 04/1800 UTC the advisories from Nadi
indicated that some gales were occurring in the southern quadrant but
the system was never classified as a tropical cyclone. According to
Mark Kersemakers, whether or not the gales were present is debatable.
No warnings on this system were issued by NPMOC at Pearl Harbor so
there is no cyclone number.
Tropical Depression 28 February--->
-------------------------------------
Two tropical depressions formed in the South Pacific on the last day
of February. The westernmost system was located about 270 nm east-
southeast of Honiara on Guadalcanal at 0600 UTC, or just west of Santa
Cruz Island. Initially, convective organization improved rapidly and
the depression was given a good chance of developing into a tropical
cyclone. During the day the depression drifted very slowly to the
southeast but showed no further signs of strengthening. As this system
continued operating into the first 2 or 3 days of March, it will be
mentioned again in next month's summary. No warnings were issued by
JTWC on this depression so there is no cyclone number.
Tropical Depression 28 February-1 March
-----------------------------------------
The other depression to form on 28 Feb was first located about 300
nm north-northwest of Tahiti, or roughly 150 nm north of Bora Bora and
Maupiti. This weak depression drifted slowly westward and did not
develop any further. The last advisory, at 0000 UTC on 1 Mar, placed
the system 150 nm west of its initial location near 13S, 154W. As
with the depression in mid-month, NPMOC did not issue any warnings on
this system so there is no cyclone number.
***********************************************************************
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
in the following manner:
(a) FTP to: hrd-type42.nhc.noaa.gov [140.90.176.206]
(b) Login as: anonymous
(c) For a password use your e-mail address
(d) The files will be named with an obvious nomenclature--using
February as an example: feb98.tracks
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 February summary is the fifth cyclone summary in this series;
the first one covering the month of October, 1997. If anyone did
not receive any of the previous summaries, they may be downloaded
from the aforementioned FTP site at HRD. The summary files are
catalogued with the nomenclature: oct97.sum, for example.
Back issues can also be obtained from the following website
(courtesy of Michael Bath):
http://australiansevereweather.com/cyclones/>
The preliminary storm reports for all the 1997 Atlantic and Eastern
North Pacific tropical cyclones are available on the Tropical
Prediction Center's website: http://www.nhc.noaa.gov> . These
reports include the analyzed best-track for each cyclone. The staff
of JTWC is also working on an on-line version of their Annual Tropical
Cyclone Report for 1997. It is still under construction, but the
best-track files are already available for 1997 Northwestern Pacific
and North Indian Ocean cyclones. The URL is:
http://www.npmocw.navy.mil/npmocw/prods/jtwc.html>
Prepared by: Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327
***********************************************************************
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|
Document: summ9802.htm
Updated: 18th March 2008 |
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