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Monthly Global Tropical Cyclone Summary January 1998
[Summaries and Track Data] [Prepared by Gary Padgett]
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Monthly Global Tropical Cyclone Summary January 1998 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
JANUARY, 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
--> Two extremely intense cyclones roam Southwest Pacific
--> Long-lived cyclone roams Coral Sea for over three weeks
--> Cyclone brings severe flooding to northern Australia
***********************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for January: No tropical cyclones
***********************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for January: No tropical cyclones
***********************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for January: No tropical cyclones
***********************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for January: No tropical cyclones
***********************************************************************
SOUTH INDIAN OCEAN (SIO) - South Indian Ocean West of Longitude 90E
Activity for January: 1 tropical cyclone of gale intensity **
** - based on warnings from Joint Typhoon Warning Center, Guam
Tropical Cyclone 13-S 18-23 January
-------------------------------------
Information on this system is based solely on warnings issued by
the Joint Typhoon Warning Center (JTWC) on Guam. The author is unaware
of any warnings issued by the Meteorological Service of Madagascar, who
has official WMO warning responsibility for the South Indian Ocean west
of longitude 55E. Based on the 1-min average wind values reported by
JTWC, this system was at best a minimal tropical storm. All other
factors being equal, the 10-min average wind utilized by the Southern
Hemisphere centers would have been reported as less than gale force.
When the first warning by JTWC was issued at 0000 UTC on 18 Jan,
the center of the cyclone was inland over the Zambezia Province of
Mozambique, about 30 nm from the coast. Some ships were reporting
gales within about 120 nm of the center. The system was initially
forecast to move south-southwestward along the Mozambique coastline
and slowly intensify, but it drifted farther inland on 18 Jan. By
18/1200 UTC winds had decreased to 30 kts. At 0900 UTC on 18 Jan
Quelimane, on the coast of Mozambique and about 60 nm from the center
of the system, reported peak gusts of only 24 kts.
On 19 Jan the LOW turned more to the south, bringing the center
nearer the coast and allowing some very slight strengthening. Winds
were reported back at 35 kts by 0000 UTC. Some synoptic observations
from inland stations of winds in the 20-25 kt range indicated the
likely presence of 30-35 kt winds offshore. The cyclone skirted the
Mozambique coastline until 20/1200 UTC, when it turned to an east-
southeasterly course and moved into the Mozambique Channel. Although
the center was over the open water, the system did not intensify
significantly due to increasing vertical shear. At 0000 UTC on 23 Jan
the final warning by JTWC was issued, downgrading the system to a
depression just south of the southern tip of Madagascar.
The only information located by the author regarding any effects
of this storm was on Earthweek's website (http://www.earthweek.com>).
Torrential rains in Mozambique and Malawi reportedly destroyed crops
and swamped many villages. No figures regarding any loss of life
were available.
***********************************************************************
AUSTRALIAN REGION (AUS) - From Longitude 90E Eastward to Longitude 160E
Activity for January: 1 tropical depression
1 tropical cyclone of storm intensity
2 tropical cyclones of hurricane intensity
NOTE: Some of the information presented below was obtained from the
January Tropical Diagnostic Statement, prepared by the RSMC Darwin.
A special thanks to Sam Cleland for sending it to me, as well as for
providing some details of the disastrous flooding around the town of
Katherine. Also, some of the information about the Katherine flood
was forwarded to me by a personal pen-pal, Graham Lees of Perth.
Tropical Depression (formerly TC Sid - 08S) 3-11 January
----------------------------------------------------------
Tropical Cyclone Sid had made landfall along the southern coast of
the Gulf of Carpentaria in late December. The remnants meandered
around the eastern portion of the Northern Territory for several days.
By 0600 UTC on 3 Jan the LOW center had emerged back over the western
Gulf near the southeastern end of Groote Eylandt about 45 nm east-
southeast of Alyangula. The Darwin TCWC commenced issuing advices
on the LOW which was forecast to possibly regain cyclone strength
within the next day or two. The depression drifted eastward over the
next couple of days but did not strengthen significantly. The last
advice was issued at 04/0600 UTC placing the LOW's center about 150
nm north of Mornington Island. Scatterometer data at 04/1330 UTC
indicated the presence of 25-30 kt winds over the water. A report
from Mornington Island at 0300 UTC on 5 Jan indicated sustained winds
of only 13 kts with gusts to 22 kts. The LOW center was located
generally to the northeast of the island at this time.
By 0000 UTC on 7 Jan the system was showing some organization once
more, so Darwin resumed issuing advices. At 07/0000 UTC the depression
was located about 50 nm northeast of Mornington Island. Over the next
18 hrs the center drifted generally in a southeasterly direction but
did not re-intensify as forecast. The last warning, issued at 1800
UTC, located the center of the LOW about 70 nm east of Mornington
Island. The remnant circulation subsequently drifted eastward onto
the Queensland coast along the southeastern Gulf of Carpentaria, and
thence southeastward across Queensland to near the eastern coast.
Bulletins were issued by the Brisbane office on 10 and 11 Jan for
the remnants of Sid which were located just inland from the coast.
The LOW remained quasi-stationary for a couple of days in the region
just north of Townsville. The warnings called for the possibility
of 35-45 kt winds within 100 nm of the coast between Lucinda and Bowen,
mainly in the southern semi-circle. An active monsoon trough
extending north-northeastward from the LOW brought very heavy rainfall
to the region. Flooding was reported along the Tully, Herbert, Upper
Burdekin, and Haughton Rivers. Townsville recorded 549 mm of rain in
the 24-hr period ending at 9 AM on the 11th, with another 245 mm
falling during the next two days.
Since the center of the LOW remained inland and moved very little
during the two-day period, no track is given for this portion of Sid's
life in the accompanying track file. The LOW was quasi-stationary in
the vicinity of 18.7S, 146.5E with the lowest central pressure during
this period reported at 998 mb.
Tropical Cyclone Katrina (TC-12P) 1-25 January
------------------------------------------------
Tropical Cyclone Katrina, while not as intense as the two concurrent
cyclones Ron and Susan farther east, certainly became the longest-lived
cyclone of the Southern Hemisphere season so far, wandering along on a
contorted track for over three weeks across the Coral Sea and South
Pacific. Cyclones of this duration, however, are not all that rare in
the South Pacific area. Just last March Tropical Cyclone Justin was
in existence from 3-25 March, generally meandering in the same area as
Katrina. Even slightly longer was Tropical Cyclone Rewa which lasted
from 28 Dec, 1993, until 22 Jan, 1994. Rewa became an intense cyclone
with winds well in excess of 100 kts, weakened and all but dissipated,
then staged a comeback and regained its former intensity. (For the
record, this information on Rewa was obtained from the former Weekly
Tropical Cyclone Summaries authored by Jack Beven.)
The first depression advisory was issued at 1800 UTC on New Year's
Day, locating the developing system about 340 nm east-northeast of
Cairns and 425 nm southeast of Port Moresby, Papua New Guinea. Katrina
was named at 03/0000 UTC while moving slowly on an east-northeasterly
course. A wind report of 31 kts from Lihou Reef at 02/2330 prompted
JTWC to begin issuing warnings on the system at this time. Katrina's
maximum 10-min average sustained winds had reached 45 kts by 4 Jan,
as reported in the warnings issued by the Brisbane TCWC. Further
intensification was halted for several days due to the low-level inflow
being dominated by the extremely intense Susan located about 1000 nm
to the east.
By the 7th Susan was moving farther south and Katrina began to
intensify steadily. At 1800 UTC on 6 Jan the storm passed 325 nm to
the north of the Chesterfield Islands. Around 07/0000 UTC Katrina
crossed longitude 160E into the Fiji area of warning responsibility.
Ever since its inception Katrina had been moving on a slow east-
northeasterly course. At 0600 UTC on 7 Jan the cyclone was centered
about 50 nm southeast of Rennel Island, the southernmost of the Solomon
Islands. This proved to be the northernmost point of Katrina's track.
The storm turned initially to the east-southeast, then more to the
southeast as it slowly increased to hurricane strength.
Katrina was becoming more of a threat to Vanuatu on 9 Jan when it
abruptly halted about 200 nm west-northwest of Vila at 1200 UTC and
reversed its direction to a westerly course due to the development of
a high pressure area directly to its south. Around this time the
storm reached its first peak intensity of 80 kts (10-min avg). During
its initial hurricane phase Katrina was a rather compact system. A
slow weakening trend set in as Katrina began to move slowly to the
west-northwest. The storm passed about 150 nm south of Rennel Island
at 1200 UTC on 11 Jan, and crossed back into the Brisbane area six hrs
later at a point about 55 nm south of the point where it crossed 160E
on its eastbound journey. Katrina was moving to the northwest at this
time, but then turned to a westerly course which it maintained until
the 15th.
At 1800 UTC on 14 Jan Katrina was a minimal hurricane located about
325 nm east-northeast of Cooktown on the Queensland coast. On the 15th
the storm began to move on a general south-southwesterly course toward
Australia. Peak intensity of 90 kts, with an estimated central
pressure of 940 mb, was attained around 1800 UTC about 250 nm east-
northeast of Cooktown. After this Katrina began to weaken rather
rapidly and its forward motion slowed. The storm described a tight
loop on 17-18 Jan about 175-200 nm east-southeast of Cooktown. Holmes
Reef reported 50-kt sustained winds at 18/0300 UTC, and it was noted
that convection and organization had increased once more. After
completing the loop Katrina moved east for about 12 hrs, then set out
on an east-southeasterly course for the next three days. During this
time Katrina briefly reached hurricane strength once more.
The southeastward motion came to a halt at 21/1800 UTC about 275 nm
east-northeast of Rockhampton. By this time Katrina was experiencing
considerable vertical shear and had weakened to well below hurricane
force. The storm began to move on a northerly course, turning to more
of a northwesterly course on 23 Jan. Winds had dropped below gale
force by 24/1200 UTC, and the last advice at 0600 UTC on 25 Jan located
the weak system about 250 nm east of Townsville. This location was
also about 250 nm south of Katrina's point of origin. The remnant LOW
drifted slowly northwestward over the next several days with convection
occasionally flaring up. Satellite classifications were issued
sporadically on into the first week of February, with the last one
noted by the author placing the weak system in the vicinity of the Cape
York Peninsula.
One fatality was reported in Vanuatu when a man fishing from a reef
was swept away by the rough seas. In the Solomon Islands, 200 homes
were destroyed on southern Guadalcanal and 450 homes destroyed on the
islands of Rennel and Bellona to the south as Katrina brushed by.
Tropical Cyclone Les (TC-14P) 23 Jan-->
-----------------------------------------
A weak tropical LOW had moved westward over the Cape York Peninsula
in late January and showed signs of development after emerging into the
Gulf of Carpentaria. The system was assisted in its development by a
brief surge in the northwest monsoon and a tightening pressure gradient
due to a high pressure area forming in the Great Australian Bight.
The first warning issued by the Darwin TCWC at 1200 UTC on 23 Jan
placed the LOW about 175 nm northeast of Mornington Island with 25-kt
sustained winds. The depression moved steadily westward and
intensified, becoming Tropical Cyclone Les at 0000 UTC on 24 Jan in
the central Gulf. By 1630 UTC the cyclone was centered about 50 nm
east-southeast of Alyangula with central sustained winds estimated at
55 kts (10-min avg). Gusts to hurricane force were being experienced
along the east coast of Groote Eylandt. Les continued westward,
crossing the southern portion of Groote Eylandt, and making landfall
around 25/0000 UTC on the eastern Gulf coast of the Northern Territory.
Peak gusts were estimated near 75 kts as Les made landfall.
Winds diminished to below gale force after the center had moved
inland, and the weakened Les spent the next three-and-a-half days
moving slowly westward over Arnhem Land. Around 0000 UTC on 26 Jan the
LOW passed near the town of Katherine where very severe flooding was
experienced. By 27/2100 UTC the center was nearing the coast about
175 nm south of Darwin and showing some signs of rejuvenation. The
center moved offshore into the Joseph Bonaparte Gulf around 1800 UTC
on 28 Jan and organization began to slowly improve. Les moved
westward across the gulf and winds had increased to 40 kts just as the
center moved back inland again around 1200 UTC on 29 Jan. Some of
the gale force winds reported during this period were monsoon gales
well away from the center of the circulation.
The cyclone turned to a west-southwesterly course for the next
couple of days and skirted the coast with the center remaining just
inland from the Timor Sea. Even though the center of Les was overland,
the proximity to the ocean allowed the system to maintain good
organization and to strengthen some. Outflow was good and a large area
of convection accompanied the storm. With the center inland the area
of gale force winds was mostly confined to the northern semicircle.
A ship near 13.6S, 127.6E on 29 Jan (exact time unknown) reported winds
to 40 kts, and on 30 Jan gales with gusts to 55 kts were being reported
along the North Kimberley coast between Wyndham and Kuri Bay.
By 31/0600 UTC the center of Les was located about 100 nm northeast
of Broome. At this point the cyclone turned to a more southwesterly
course which took it farther inland. At 0000 UTC on 1 Feb winds had
dropped to 30 kts and the weakening cyclone was then about 50 nm south-
southwest of Broome. (This based upon official warnings from Perth--
JTWC kept the overland system at minimal gale force for another day
or so.)
Before being named as a cyclone the pre-Les system dropped 50-100 mm
of rain on the Cape York Peninsula, and after Les had moved inland over
Arnhem Land, rainfalls of from 100 to 385 mm were recorded. The main
guage at Katherine recorded 220.8 mm for the 24 hrs ending at 9AM on
the 26th, and 159.8 mm during the next 24 hrs. The total rainfall at
Katherine for the month of January was 913.8 mm, making it the wettest
January in 124 years of record. The annual average is 969 mm, while
the January average is 235.5 mm.
Flooding in and around the town of Katherine, often called the
"Jewel of the Northern Territory", was particularly severe. Many
houses were completely under water and the water rose to the rooflines
in the downtown area. The Katherine River rose to its highest level
on record of 20.4 metres---about 17 metres higher than normal. The
Australian government declared Katherine a disaster area, and the
entire town will have to be rebuilt. At least one death was
reported, and there could have been others. Quite a number of the
semi-homeless aborigines had their camps washed away.
Tropical Cyclone Tiffany (TC-15S) 24-31 January
-------------------------------------------------
Advisories were begun on a new tropical LOW by the Perth TCWC at
0000 UTC on 24 Jan placing the center about 100 nm northeast of Broome.
This system was of land origin and had drifted westward over the ocean.
A brief surge of southeasterly flow aided in the intensification of the
system, and Tiffany was christened at 25/0600 UTC about 100 nm west-
northwest of Broome. Tiffany was a small system and intensified
rapidly on the 26th with satellite estimates increasing 35 kts in a
12-hr period. Hurricane force was reached at 1200 UTC about 125 nm
north of Port Hedland. Peak intensity of 100 kts and 930 mb central
pressure was reached around 27/0000 UTC when Tiffany was centered about
100 nm north of Roebourne. (JTWC reported the maximum sustained 1-min
wind at 120 kts. Adjusting this to its equivalent 10-min avg yields
105 kts, which is in very good agreement with Perth's intensity.)
Tiffany maintained 100-kt winds for 18-24 hrs before beginning to
weaken. The cyclone continued on a general west-southwesterly course
which took it farther away from the Australian coastline. By 29/0600
UTC winds had dropped below hurricane force. Perth issued the last
warning at 0600 UTC on 30 Jan locating the weakening cyclone about
500 nm west-northwest of Onslow. JTWC issued another couple of
warnings with the system being downgraded to a depression at 0000 UTC
on 31 Jan.
Although Tiffany was quite intense and moved fairly close to the
Western Australian coastline, it was a small, compact system and its
effects on Australia were minimal.
***********************************************************************
SOUTHWEST PACIFIC (SWP) - South Pacific Ocean East of Longitude 160E
Activity for January: 2 tropical depressions
1 tropical cyclone of gale intensity
1 tropical cyclone of storm intensity
3 tropical cyclones of hurricane intensity
NOTE: A special thanks as always to Mark Kersemakers of the Fiji
Meteorological Service and to Steve Ready of the Meteorological Service
of New Zealand for passing along information regarding damage and
casualties caused by South Pacific cyclones. Most of the information
on the effects of Ron came from a report by Paea Havea, Chief Officer
of the Tonga Meteorological Service.
Tropical Cyclone Ron (TC-10P) 1-9 January
-------------------------------------------
Tropical Cyclone Ron, along with its twin, Susan, were the two most
intense cyclones to form in the South Pacific in recent years. Both
generated estimated 10-min average maximum sustained winds of 125 kts
(equivalent to 144 kts 1-min average) with attendant minimum central
pressure estimated at 900 mb. The last tropical cyclone to possibly
reach this intensity was Tropical Cyclone Hina in March of 1985.
The first depression bulletin on the pre-Ron system was issued at
01/0600 UTC with the system centered about 450 nm northeast of Samoa.
The depression drifted slowly on a west-southwesterly course for the
next four days, reaching tropical cyclone intensity at 0000 UTC on
2 Jan about 350 nm northeast of Samoa. As a storm Ron passed very near
Swains Island around 03/0000 UTC. Intensification proceeded at a
fairly rapid rate after that. Peak intensity of 125 kts was reached
at 0600 UTC on 5 Jan with Ron centered about 225 nm north-northwest of
Apia in Western Samoa. The cyclone maintained this strength for about
36 hrs. After 1200 UTC on the 5th Ron turned to a south-southwesterly
course for about 18 hrs, then began to move in a south-southeasterly
direction. Around 06/1800 UTC the cyclone, with maximum winds still
estimated to be near 110 kts, passed very close to the island of
Niuafo'ou, where considerable destruction occurred. At 1800 UTC
Niuafo'ou reported sustained winds of 60 kts with a presure of 983.7
mb. The lowest pressure from the island during Ron's passage was
972.4 mb with maximum winds from 65-80 kts, but these winds were
estimated. Ron was a very compact cyclone--at 05/0000 UTC Wallis
Island, then located about 95 nm southeast of the center, reported
10-min average winds of only 17 kts with gusts to 32 kts. The Nadi
discussion at 06/0800 UTC mentioned that based on winds reported by
Niuafo'ou, Ron may have had an even smaller gale radius and stronger
winds near the center than had been thought.
After passing Niuafo'ou Ron began to weaken steadily as it started
to accelerate to the southeast. The storm passed over 400 nm south of
Samoa around 0000 UTC on 8 Jan with maximum winds estimated at 85 kts.
After this Ron began to move quickly to the southeast as it rapidly
weakened, and the system had merged with Tropical Cyclone Susan by
09/0000 UTC.
The greatest damage from Tropical Cyclone Ron occurred on the Tongan
island of Niuafo'ou (population 735). About 67% of the buildings were
either damaged or destroyed (many of these were Tongan fales--thatched
houses). Agricultural losses were also severe--from 80-90% of coconut
and breadfruit trees were damaged, and losses for native food crops
such as taro, kape, manioc, and bananas were estimated at 95%. _The
Tonga Chronicle_ reported that it would take about five years to bring
crop production back to pre-cyclone levels. The estimated cost for
rehabilitation (houses, food, water, etc) is placed at approximately
$1.1 million in Tongan dollars. Fortunately no deaths were reported.
Damage was also reported on the Tongan islands of Niuatoputapu,
Tafahi, and Vava'u but was generally not as severe as on Niuafo'ou.
No reports of damage have been received from Swains Island (which is
part of American Samoa) or from Wallis Island (a French territory).
Tropical Cyclone Susan (TC-11P) 3-9 January
---------------------------------------------
Tropical Cyclone Susan developed from a disturbance which had
actually been tracked since around 20 December. The disturbance was
first noted several hundred miles northeast of Samoa. Over the next
two weeks the system drifted very slowly west-southwestward. Nadi had
issued a couple of bulletins on the system on 20 and 21 Dec, and again
from 24-26 Dec when the system became better organized; however, on
both occasions convection decreased and the system weakened. During
this time neither NPMOC nor JTWC issued depression warnings, although
Dvorak bulletins were issued sporadically on the LOW.
Finally at 0000 UTC on 3 Jan, Nadi resumed issuing depression
bulletins on the system which was then located west of Rotuma, and
Susan was named just 6 hrs later with the center placed about 450 nm
north of Fiji. Susan intensified rapidly, and only 18 hrs after being
named the storm had reached hurricane force. Tropical Cyclone Susan
initially moved slowly westward, then turned to a west-southwesterly
course. By 04/1200 UTC Susan was moving southwest, and after 1800 UTC
on 5 Jan, made a turn to the south-southeast. On the afternoon of
the 5th the storm came within about 225 nm of Vila, Vanuatu. Susan by
this time had reached its peak itensity of 125 kts sustained winds and
900 mb estimated central pressure. The cyclone posed a severe threat
to Vanuatu, but fortunately changed course in time to spare the islands
a direct hit.
After turning away from Vanuatu Susan began to track toward the
southeast at a faster rate of speed. Peak intensity was maintained
for about 36 hrs--until after 1200 UTC on 6 Jan. On 7 and 8 Jan Susan
passed closed enough to Fiji to cause some gales in the westernmost
islands of the group. The center passed about 200 nm south-southwest
of Nadi around 07/1800 UTC with winds still near 110 kts. At 2100 UTC
on the 7th a ship at 20.1S, 172.7E (about 250 nm west-northwest of the
center) reported winds of 50 kts. Susan appeared to have concentric
eyes on at least a couple of occasions.
After passing by Fiji Susan accelerated greatly on a southeasterly
course across the South Pacific. Cyclone Ron had merged with the
system by 09/0000 UTC and Susan was becoming extratropical by 0600 UTC
about 725 nm east-northeast of Auckland, New Zealand. Winds remained
well above hurricane force as Susan made the transition to a vigorous
extratropical cyclone.
Overall, damage from Tropical Cyclone Susan was minor. High seas
inundated Talaulia village on Kadavu, Fiji, and partly destroyed some
beachfront buildings, roads, jetties, and bridges on the island. On
Beqa Island damage from high seas/swells was also experienced. In
the town of Lautoka, on Viti Levu, roofs were blown off some shops.
This damage was believed to have been caused by a tornado which formed
in one of the outer rain bands as it crossed the shoreline. One death
was reported on Ambrym Island, Vanuatu, when a woman was struck and
killed by a falling coconut palm.
Tropical Cyclone Katrina (TC-12P) 7-11 January
------------------------------------------------
Tropical Cyclone Katrina, a long-lived cyclone which roamed the
Coral Sea and South Pacific for over three weeks, formed on 1 Jan west
of 160E in the Brisbane TCWC's area of responsibility. While Katrina
spent most of its long life in the Australian Region, it did cross 160E
and was in the Southwest Pacific Basin from 7 to 11 Jan, where it posed
a threat to Vanuatu on 8 and 9 Jan. The full report on this cyclone
can be found in the portion of this summary covering the Australian
Region.
Tropical Cyclone Tui (TC-16P) 25-27 January
---------------------------------------------
Tropical Cyclone Tui was a short-lived cyclone whose winds did not
exceed gale intensity. The system passed over the eastern part of
the island of Savai'i in Western Samoa, causing relatively minor damage
but unfortunately causing one death. A young boy was electrocuted when
he stepped into a puddle of water that contained a live downed power
line. Maximum sustained winds (10-min) in Savai'i were estimated near
40 kts gusting to 60 kts.
The depression from which Tui developed was first sighted about
225 nm northwest of Apia, Western Samoa around 0000 UTC on 25 Jan. The
system moved slowly on a south-southeasterly course for most of its
life. Tropical Cyclone Tui was christened at 25/2100 UTC about 50 nm
northwest of Apia. Tui passed over the eastern part of Savai'i early
on 26 Jan (UTC). At 26/0000 UTC the center was very near the AWS at
Asau (13.4S, 172.3W). A minimum pressure of 991 mb was reported but
winds were light.
After crossing Western Samoa Tui intensified slightly, reaching a
peak intensity of 45 kts around 1800 UTC on 26 Jan when located about
75 nm south-southwest of Pago Pago, American Samoa. Thereafter, Tui
remained quasi-stationary just to the south of the Samoan islands and
weakened, being downgraded to a depression by 27/1200 UTC.
Tropical Cyclone Ursula (TC-17P) 29 Jan-->
--------------------------------------------
An advisory was issued on a new, developing depression at 0600 UTC
on 30 Jan, locating the system about 125 nm north-northwest of Tahiti.
The system was moving slowly to the southeast. By 30/1800 UTC gale
intensity had been reached and the cyclone was named Ursula. At the
time it was named, Ursula was located about 150 nm northeast of Tahiti.
Over the next few days Tropical Cyclone Ursula moved on a southeasterly
course which took it through the middle of the Tuamotu Archipelago.
The storm passed well east of Tahiti and seemed to move generally to
the southwest of and parallel to the main chain of islands in the
Tuamotu group.
Ursula's forward motion increased considerably on 31 Jan, and by
0000 UTC on 1 Feb the storm was located far to the southeast of Tahiti
and about 500 nm west-northwest of Pitcairn Island. Maximum 10-min avg
winds had increased to an estimated 55 kts by this time. Surprisingly,
NPMOC at Pearl Harbor never issued any warnings on this system until
0600 UTC on 1 Feb, when their first warning classifed Ursula as a
hurricane.
Very few tropical cyclones move as far east in the South Pacific as
did Ursula. The greater than normal tropical cyclone activity in this
area in recent months can likely be attributed to the warmer SSTs and
especially lower atmospheric pressures in the region due to the current
warm phase of ENSO. The author at this point has not received any
damage reports from the areas through which Ursula passed. If any do
become available they will be reported in the February summary.
Two Tropical Depressions 31 January-->
----------------------------------------
Two new depressions formed on 31 January: the first one was about
125 nm northwest of Apia, Western Samoa, at 0600 UTC; and the first
bulletin on the second at 1200 UTC located it about 250 nm east-
southeast of Manihiki Atoll in the Northern Cooks. The second and
easternmost depression was upgraded to Tropical Cyclone Veli at 0000
UTC on 1 Feb, and the depression north of Samoa became Tropical Cyclone
Wes six hours later. The reports on these cyclones will be contained
in the February summary.
***********************************************************************
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
January as an example: jan98.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 January summary is the fourth 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.
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
***********************************************************************
***********************************************************************
|
Document: summ9801.htm
Updated: 18th March 2008 |
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