[Index]
Monthly Global Tropical Cyclone Summary February 2003
[Summaries and Track Data] [Prepared by Gary Padgett]
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Cyclones
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Monthly Global Tropical Cyclone Summary February 2003 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
FEBRUARY, 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.)
*************************************************************************
FEBRUARY HIGHLIGHTS
--> Twin tropical cyclones in Southwest Indian--one brushes Mauritius
--> First named Australian cyclones of season form
--> Very intense cyclone forms in Southeast Pacific
--> Damaging tropical cyclone strikes Mozambique
*************************************************************************
***** Feature of the Month for February *****
SOUTHERN HEMISPHERE TROPICAL CYCLONE STATISTICS
-----------------------------------------------
For this month's feature I am highlighting a compilation of various
statistics on Southern Hemisphere tropical cyclones (TCs) prepared by
Patrick Hoareau of Rennes, France. These can be accessed on Michael
Bath's website:
http://australiasevereweather.com/cyclones/stats.htm>
One caveat is in order: Patrick based his work entirely on JTWC's
Best Track database, so this should be kept in mind when comparing his
statistics with those of the official WMO warning centres or any other
such study.
Several different types of charts or categories of charts are
available, and I have detailed these below:
(1) Monthly distribution of all tropical cyclones
This chart covers the period 1969/1970 through the 2001/2002 season,
and lists the number of TCs (including depressions) for which JTWC
issued warnings by month. The most active season was 1996/1997 when
38 TCs developed; the two least active seasons were 1987/1988 and
2000/2001 when only 21 TCs were tracked by JTWC. The single most
active month was January, 1975, when 14 TCs were charted.
(2) Distribution of tropical cyclones at maximum intensity
This chart covers from the 1982/1983 season to the present and lists
the seasonal totals of TCs reaching a 1-minute average MSW of
35 kts, 65 kts, 100 kts, 120 kts, and 130 kts. The peak number of
intense TCs (MSW of 100 kts or greater) was 11, and was reached in
1991/1992 and in 1993/1994.
NOTE: The current total (as of 08 April) for the 2002/2003 season
is also 11, thus tying the two seasons referenced above. The
intense TCs so far this season have been Zoe, Ami, Beni, Dovi, Erica
and Eseta in the South Pacific Ocean; and Gerry, Fiona, Japhet,
Kalunde and Inigo in the South Indian Ocean. Five of these
systems (Zoe, Dovi, Erica, Kalunde and Inigo) reached JTWC's "super
typhoon" intensity of 130 kts, and Beni came very close (125 kts).
(3) Distribution of tropical cyclones at maximum intensity in the
Southern Indian Ocean
This chart is similar to (2) but covers the South Indian Ocean,
i.e., from the African coast to longitude 135E.
(4) Distribution of tropical cyclones at maximum intensity in the
South Pacific Ocean
Identical to (3) except for the region 135E eastwards to the
South American coast.
(5) Start date and end date of tropical cyclone seasons
This interesting chart contains information on TC seasons for the
period 1984/1985 through 2001/2002. Items tabulated include the
starting date of the season, number of early season TCs (forming
before 1 January), end of season dates, overall number of TCs,
and the number of warnings issued (by JTWC). The earliest starting
seasons were those of 1989/1990 and 1996/1997 which began on
10 July. The latest ending season was 1986/1987 which ended on
27 June. The largest number of early season TCs was 13 during the
1996/1997 season.
(6) Mean number of hurricane/typhoon intensity tropical cyclones
by month
(7) Strongest tropical cyclones
This chart is based on the period 1980/1981 through 2001/2002 and
lists all the TCs which reached a MSW of 120 kts per JTWC's
analysis. The most intense for the entire Southern Hemisphere was
Tropical Cyclone Agnielle in the South Indian Ocean in November,
1995, which was analysed to have peaked at 150 kts. The most
intense TC for the South Pacific listed is Tropical Cyclone Ron in
January, 1998, which peaked at 145 kts. The only other TC which
reached 145 kts was Tropical Cyclone Geralda in January, 1994.
NOTE: If the operational intensity of 155 kts for the recent
Tropical Cyclone Zoe stands in post-storm analysis, Zoe will become
the new record-holder for the Southern Hemisphere and the South
Pacific. Tropical Cyclone Ron, however, still holds the record for
the most intense TC east of the Dateline in the South Pacific.
(8) Strongest tropical cyclones by month
(9) Average early and late season tropical cyclones by basin
(10) Average genesis, peak intensity and cyclolysis (death) by basin
This section consists of a series of annual charts covering the
period 1982/1983 through 2000/2001 and gives the average number of
formations, peak intensities, and dissipations occurring in six
"basins", probably more aptly called "sub-basins":
(a) Africa to 70E
(b) 70E - 100E
(c) 100E - 135E
(d) 135E - 180
(e) 180 - 150W
(f) 150W to South America
(11) Best track summary
For the period 1993/1994 through 2000/2001, this gives the average
number of synoptic times (6-hourly data points) with the MSW in
various intensity ranges, e.g., tropical storm, hurricane, etc.
(12) Best tracks for individual seasons
Annual charts for 1993/1994 through 2000/2001, listing each TC with
similar information as in item (11).
I referred to Patrick's statistics in a monthly feature last year
(May) when I highlighted some of my friends TC-related websites.
Hopefully this more detailed description of Patrick's work will
encourage interested persons to visit Michael's great website and
explore Patrick's charts as well as some of the wealth of additional
information Michael has made available.
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for February: No tropical cyclones
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for February: No tropical cyclones
*************************************************************************
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
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for February: 1 moderate tropical storm
1 tropical cyclone
2 intense tropical cyclones
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Southwest Indian Ocean tropical cyclones are the warnings issued by
the Tropical Cyclone Warning Centre on La Reunion Island, part of
Meteo France (MFR), and the Regional Specialised Meteorological Centre
for the basin. However, tropical cyclones in this region are named
by the sub-regional warning centres on Mauritius and Madagascar with
longitude 55E being the demarcation line between their respective
areas of warning responsibility. The La Reunion centre only advises
these agencies regarding the intensity of tropical systems. References
to sustained winds imply a 10-minute averaging period unless otherwise
stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from MFR's coordinates by usually
40-50 nm or more. The JTWC warnings are also the source of the
1-minute average maximum sustained wind values included in the
tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Southwest Indian Ocean Tropical Activity for February
-----------------------------------------------------
The South Indian Ocean west of 90E was quite active during the month
of February. Four named systems developed; three reached tropical
cyclone (i.e., hurricane) intensity, and of these three, two became
intense tropical cyclones (10-min mean wind greater than or equal to
90 kts). Tropical Cyclones Gerry and Hape and Tropical Storm Isha all
formed at about the same time with all three following easterly or
southeasterly trajectories. Gerry reached the intense cyclone threshold
of 90 kts right at the time it made its closest approach to Mauritius,
passing about 65 nm east of the northern tip of the island. Hape and
Isha were further east and had no effect on land. Late in the month,
intense Tropical Cyclone Japhet formed in the Mozambique Channel and
eventually made landfall in Mozambique as a fairly strong cyclone,
equivalent to a Category 2 hurricane on the Saffir/Simpson scale.
Reports on all four systems follow.
TROPICAL CYCLONE GERRY
(MFR-10 / TC-16S)
8 - 17 February
------------------------------------------
Gerry: contributed by Kenya
A. Storm Origins
----------------
What would become the first intense cyclone of the 2002-2003 season
in the Southwest Indian Ocean had its beginnings in an area of convection
which developed on 7 February about 320 nm north-northwest of Mauritius.
Animated multi-spectral satellite imagery indicated persistent convection
associated with a weak LLCC. An upper-air analysis revealed favorable
diffluence and weak vertical shear over the disturbance. JTWC rated the
potential for development as fair. MFR initiated bulletins on Tropical
Disturbance 10 at 08/0600 UTC and JTWC issued a TCFA at 0630 UTC.
Convective organization near the LLCC had improved and a 200-mb analysis
indicated continued favorable conditions aloft.
JTWC issued the first warning on TC-16S at 1800 UTC. The center was
located approximately 350 nm north-northwest of Mauritius, and the MSW
(1-min avg) was estimated at 30 kts. MFR upgraded the system to a
30-kt depression at 0000 UTC on 9 February. The depression was drifting
slowly northward or north-northwestward and was then located about
400 nm north-northwest of Mauritius. JTWC relocated the center farther
north at 09/0600 UTC based on recent visible and SSM/I imagery and upped
the MSW (1-min avg) to 35 kts. By 1800 UTC the system had reached a
point 490 nm north-northwest of Mauritius and was moving northwestward
at 5 kts. The LLCC remained broad and partially-exposed with the deep
convection located to the west of the center.
B. Track and Intensity History
------------------------------
At 0600 UTC on 10 February JTWC increased the estimated MSW (1-min
avg) to 45 kts, and MFR upped the 10-min avg intensity to 35 kts. The
Meteorological Services of Mauritius named the system Tropical Storm
Gerry, located approximately 550 nm north-northwest of Mauritius. Gerry
began tracking slowly toward the south-southeast and by 11/0600 UTC was
located about 450 nm north-northwest of Mauritius. The storm had not
strengthened significantly with the intensity being reported at 40 kts.
(JTWC was estimating 60-kts 1-min avg at the time). There is a
possibility that Gerry was experiencing some interaction with Tropical
Storm Hape about 600 nm to the southwest. Gerry began to strengthen
later on the 11th as it continued trekking south-southeastward in the
direction of Mauritius, and at 1200 UTC on 12 February, MFR upgraded
the storm to tropical cyclone (i.e., hurricane) status with 65-kt winds
when it was located approximately 225 nm northwest of Mauritius. (JTWC's
previous warning at 12/0600 UTC had reported 55 kts, but at 1800 UTC the
MSW was jumped up to 75 kts, based on CI estimates of 77 kts.)
During the next 12 hours the tropical cyclone intensified rather
rapidly as it neared Mauritius. MFR increased the intensity to 90 kts
at 13/0600 UTC, making Gerry the first intense tropical cyclone of the
season. (JTWC's estimated 1-min avg MSW was 105 kts, roughly equal to
MFR's 10-min avg estimate.) The cyclone at this time was near its
closest point of approach to Mauritius, being centered about 65 nm east-
northeast of Cap Malheureux (the northern tip of the island). Intense
Tropical Cyclone Gerry displayed a well-defined eye, and an upper-air
analysis indicated favorable outflow in all quadrants. Storm-force winds
extended outward 50 nm from the center while gales reached outward around
90 nm in the southern semicircle and 120 nm to the north. (JTWC's gale
radii were about 30-40 nm larger than MFR's.) Very fortunately for
Mauritius, Gerry's motion became more east-southeasterly as it neared the
island. This kept the more dangerous left semicircle further away from
Mauritius and resulted in the storm's just brushing the island rather
than striking directly--something which had appeared very possible
24 hours earlier. The MSW estimates of 90 and 105 kts from MFR and
JTWC, respectively, represent the peak intensity for Tropical Cyclone
Gerry, and the minimum CP estimated by MFR was 940 mb.
Gerry weakened rather quickly after passing Mauritius. By 13/1800
UTC, although the storm was still intense, deep convection was beginning
to erode in the northern portion of the banding eye feature. By 14/1200
UTC, only 24 hours after reaching peak intensity, MFR downgraded Gerry
to a 60-kt tropical storm, and JTWC lowered their 1-min avg MSW estimate
from 100 kts at 14/0000 UTC to 75 kts at 1200 UTC (based on CI estimates
of 65 and 77 kts). Gerry was located 420 nm southeast of Mauritius, or
about 300 nm south of Rodrigues, moving southeastward at 8 kts. Animated
satellite imagery revealed an exposed LLCC decoupled approximately 30 nm
northwest of the deeper convection.
By 15/0000 UTC Gerry was moving quickly southeastward at 17 kts. The
broad LLCC was devoid of convection, and a weak cold front appeared to
have developed and was extending north and west of the system. A more
well-defined area of clouds to the east of Gerry was analyzed to be a
moderate warm front with warm air advection. An upper-level analysis
indicated an upper-level jet south of the system with an associated
gradient of increasing vertical shear. JTWC issued their final warning
on Gerry at 15/1200 UTC with the system located about 700 nm southeast of
Mauritius, moving southeastward at 6 kts. An earlier QuikScat pass had
revealed a broad area of gale-force winds and MFR continued to estimate
the intensity at 40 kts through 1800 UTC. At 16/0000 UTC Gerry was
downgraded to a depression, although some spots of gale-force winds were
still occurring well south and east of the center. The system was
declared extratropical at 16/1200 UTC when located about 650 nm southeast
of Rodrigues. MFR issued the final gale warning on the extratropical
depression at 1200 UTC on 17 February.
C. Meteorological Observations
------------------------------
At 1800 UTC on 11 February the center of Gerry lay approximately
65 nm west-northwest of Tromelin Island (15.9S, 54.5E). The island
reported a sustained wind (10-min avg) of 35 kts with a peak gust of
51 kts at that hour. The peak gust for the storm of 60 kts and minimum
SLP of 986 mb occurred at 2100 UTC.
The peak wind gust recorded on Mauritius was 78 kts at Ft. William,
near Port Louis. Gusts of 55-70 kts were common over the northern end
of the island. Thomas Birger recorded a minimum SLP of 989.9 mb at
his home. Some of the higher 24-hour rainfall amounts include 139.2 mm
at Mare aux Vacoas, 130.6 mm at Vacoas, and 129.8 mm at Trou aux Cerfs.
Tropical Cyclone Gerry caused some very high seas in northern Mauritius.
Local inhabitants stated that the seas were more furious than those
caused by Tropical Cyclone Hollanda in 1994 and Tropical Cyclone Dina
in 2002. According to Thomas Birger, the seas kicked up by Gerry were
the most spectacular seen in Mauritius since those resulting from
Tropical Cyclone Gervaise in 1975 and Tropical Cyclone Alix in 1960.
(A special thanks to Karl Hoarau and Thomas Birger for sending me
the above information.)
D. Damage and Casualties
------------------------
There was only one fatality attributed to Tropical Cyclone Gerry
in Mauritius--a doctor who was electrocuted during the storm. Even
though parts of the island experienced hurricane-force wind gusts,
damage was negligible according to Jean Marc de Maroussem, who lives
in Mauritius.
(Report written by Gary Padgett)
TROPICAL CYCLONE HAPE
(MFR-11 / TC-17S)
9 - 16 February
-----------------------------------------
Hape: contributed by Lesotho
A. Storm Origins
----------------
Tropical Cyclone Hape was more or less a twin of Tropical Cyclone
Gerry which was operating farther west. MFR initiated bulletins on
Tropical Disturbance 11 at 0600 UTC on 9 February, located roughly
500 nm southwest of Diego Garcia. Around 1800 UTC animated enhanced
infrared and visible imagery revealed a small LLCC associated with
persistent deep convection. A 200-mb analysis indicated favorable
outflow aloft and JTWC rated the potential for development as fair.
The disturbance drifted westward for the next day or so, gradually
improving in organization. MFR upgraded the system to tropical
depression status at 0600 UTC on the 10th, locating the center about
650 nm southwest of Diego Garcia. JTWC issued a TCFA at 0530 UTC,
but placed the center farther north at a position approximately 580 nm
southwest of Diego Garcia. By 1800 UTC the center was located about
460 nm east-northeast of Mauritius, moving southward at 11 kts. JTWC
issued the first warning on TC-17S, estimating the MSW (1-min avg) at
40 kts, based on CI estimates of 35 and 45 kts. A 10/1741 UTC SSM/I
pass had depicted a well-defined circulation with a band of deep
convection in the northern semicircle.
B. Track and Intensity History
------------------------------
At 0600 UTC on 11 February the Meteorological Services of Mauritius
named the depression Tropical Storm Hape, located approximately 450 nm
east-northeast of Mauritius or about 200 nm north-northeast of Rodrigues.
MFR estimated the MSW (10-min avg) at 35 kts while JTWC upped the 1-min
avg MSW to 45 kts, based on CI estimates of 35 and 45 kts. An 11/0427
UTC SSM/I pass had suggested the formation of an eye, but the CDO had
subsequently begun to weaken. Hape was trekking south-southeastward at
11 kts, and this motion was forecast to continue for the next 48 hours
as the system was guided by a near-equatorial ridge to the north-
northeast. Once having reaching tropical storm status, Hape began to
intensify rapidly. Only six hours later MFR upped the intensity to
60 kts, and at 1800 UTC JTWC estimated the MSW (1-min avg) at 75 kts
based on CI estimates of 65 and 77 kts. An 11/1726 UTC SSM/I pass
depicted a 13-nm diameter eye with a deep convective band extending into
the eastern and northern quadrants. Animated water vapor imagery
depicted poleward outflow being enhanced by a passing trough to the
southeast.
MFR upgraded Hape to tropical cyclone (i.e., hurricane) status at
12/0000 UTC when the system was centered approximately 250 nm northeast
of Rodrigues. Six hours later Hape reached its peak intensity of
70 kts (80 kts per JTWC) with the CP estimated at 965 mb. Hape's track
had become more east-southeasterly by late on the 11th, and by the time
it reached peak intensity the cyclone was moving east-northeastward at
15 kts as it tracked toward a weakness in the near-equatorial ridge to
the north. By 1800 UTC Hape had begun to weaken slightly with MFR and
JTWC lowering their respective intensity estimates to 65 and 75 kts.
Interestingly, at 13/0600 UTC JTWC bumped their 1-min avg MSW estimate
back to 80 kts while MFR lowered the intensity to 55 kts. By 1800 UTC
on the 13th Hape was located about 450 nm south of Diego Garcia and
moving eastward at 6 kts. JTWC maintained the 80-kt intensity (based
on CI estimates of 77 and 90 kts) while MFR raised their 10-min avg MSW
estimate back to 60 kts.
Hape's intensity had come down to 50 kts (65 kts per JTWC) by 0600 UTC
on 14 February and the storm had begun tracking southeastward at 7 kts
under the influence of a building subtropical ridge to the east-
northeast of the system. Recent microwave imagery revealed that while
the LLCC was still well-defined, deep convection had dissipated over the
center. Animated water vapor imagery indicated that the outflow pattern
over Hape had become unfavorable due to interaction with Tropical Cyclone
Gerry, then located about 800 nm to the southwest. Satellite CI
estimates remained at 65 kts through 1800 UTC and MFR bumped the MSW up
slightly to 60 kts while JTWC lowered their 1-min avg intensity estimate
to 60 kts. The storm began to weaken rapidly thereafter. JTWC issued
their final warning on Hape at 0600 UTC on the 15th, lowering the MSW
to 35 kts and placing the center approximately 800 nm south-southeast of
Diego Garcia, moving southeastward at 23 kts. The LLCC by this time
had become completely exposed. MFR downgraded Hape to depression status
at 15/1800 UTC and issued their final bulletin at 16/0000 UTC, locating
the dissipating system almost 1300 nm southwest of the Cocos Islands.
C. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Tropical
Cyclone Hape.
(Report written by Gary Padgett)
TROPICAL STORM ISHA
(MFR-12 / TC-18S)
11 - 14 February
---------------------------------------
Isha: contributed by the Seychelles
The origins of Tropical Storm Isha are shrouded in somewhat of a
mystery. I am missing a couple of the daily STWOs from JTWC which would
probably shed a little light on the pre-warning disturbance which became
the ephemeral Isha. There was a tropical LOW in the vicinity of the
Cocos Islands for which Perth wrote gale warnings on 4-6 February. This
system may have drifted westward and latter re-intensified. However,
there was widespread disturbed weather and areas of convection in the
monsoon trough in the Southeast Indian Ocean during early February, so
Isha could well have developed from a surface circulation other than
the Australian LOW. JTWC issued the first warning on TC-18S at 0000 UTC
on 11 February with an initial MSW (1-min avg) of 30 kts. The system
was located about 650 nm southwest of the Cocos Islands and moving
southwestward at 11 kts. Satellite imagery indicated that the system's
organization had improved during the past 12 hours.
MFR initiated bulletins on Tropical Disturbance 12 at 11/1200 UTC.
The LOW was then located about 720 nm southeast of Diego Garcia and had
turned to a slow south-southeasterly track. At 12/0000 UTC the system
was located approximately 800 nm southeast of Diego Garcia and moving
east-southeastward at 8 kts. A general southeasterly track was fore-
cast to continue under the influence of a low to mid-level near-
equatorial ridge to the north. JTWC increased the MSW (1-min avg) to
40 kts, based on CI estimates of 35 and 45 kts, and at 0600 UTC MFR
upgraded the disturbance to a 30-kt tropical depression. The intensity
remained static for another 24 hours as an upper-level ridge passing
over the system seemed to be hindering development.
JTWC upped the MSW to 45 kts at 13/0000 UTC. Some of the computer
models suggested that TC-18S had interacted briefly with Tropical
Cyclone Hape. The environment had become more conducive to
strengthening by early on the 13th with a favorable outflow pattern and
weak vertical shear. At 13/0600 UTC MFR upgraded the system to Tropical
Storm Isha, located about 825 nm west-southwest of the Cocos Islands
and moving southeastward at around 10 kts. Isha's tenure as a tropical
storm (per MFR) was very brief--at 1200 UTC the storm was downgraded to
a depression. Animated water vapor imagery revealed that Isha had
weakened due to the entrainment of cool, dry air and the development of
unfavorable shear associated with a mid-latitude LOW to the south.
The weakening tropical system was forecast to continue tracking south-
southeastward under the steering influence of a low to mid-level ridge
to the east. MFR issued their final bulletin at 13/1800 UTC, downgrading
the depression to a 25-kt LOW. JTWC had maintained the 45-kt intensity
at 1200 UTC, but issued the final warning at 14/0000 UTC. The MSW
was dropped to 35 kts (1-min avg), based on CI estimates of 30-35 kts.
Enhanced infrared imagery depicted little remaining convection due to
the cool, dry air and unfavorable vertical shear. The center was
difficult to locate, but was estimated to be about 850 nm southwest of
the Cocos Islands.
No damage or casualties are known to have resulted from Tropical
Storm Isha.
(Report written by Gary Padgett)
TROPICAL CYCLONE JAPHET
(MFR-13 / TC-19S)
25 February - 3 March
-------------------------------------------
Japhet: contributed by Malawi
A. Storm Origins
----------------
Tropical Cyclone Japhet was the second tropical cyclone of the 2002-
2003 season to reach intense status (10-min avg MSW of 90 kts), and
only the sixth storm over the past 24 seasons to attain intense tropical
cyclone status in the Mozambique Channel. MFR issued the first bulletin
on Tropical Disturbance 13 at 1200 UTC on 25 February, locating a weak
25-kt center a little less than 100 nm west-southwest of Tulear on the
southwestern coast of Madagascar. At 2100 UTC JTWC issued a TCFA for
the system due to improving conditions for development. Animated
infrared imagery, a 25/1419 UTC TRMM pass, and a 25/1742 UTC SSM/I pass
indicated that a spiral cloud pattern was beginning to form, and a
25/1454 UTC QuikScat pass indicated better consolidation of the LLCC
than had been noted 12 hours previously. An upper-air analysis indicated
weak vertical shear and weak to moderate diffluence.
JTWC issued the first warning on TC-19S at 26/0000 UTC and MFR
upgraded the system to tropical depression status at 0600 UTC. The
center was located approximately 200 nm west-northwest of Tulear and
moving westward very slowly at only 2 kts. The system was forecast to
track westward through 36 hours, steered by a mid-level ridge to the
southwest, then turn poleward as the ridge moved eastward. JTWC upped
the MSW (1-min avg) to 35 kts at 1200 UTC, and at 1800 UTC the Meteor-
ological Services of Madagascar named the depression Tropical Storm
Japhet. Japhet was located about 265 nm west-northwest of Tulear and
its forward motion had almost halted and become erratic.
B. Track and Intensity History
------------------------------
At 0000 UTC on 27 February Tropical Storm Japhet was located about
230 nm east of Mozambique and moving west-northwestward at 4 kts. By
1200 UTC the storm had taken an abrupt turn toward the south-southwest
toward a weakness in the ridge lying to the south. The storm had been
steadily intensifying and the MSW was up to 55 kts. The intensification
continued and JTWC upped the intensity to 75 kts (1-min avg) at 0000 UTC
on the 28th, based on CI estimates of 65 and 77 kts. Japhet at this time
was about 130 nm east of the Mozambican coast and moving south-southwest
at 8 kts. At 0600 UTC MFR officially upgraded Japhet to tropical
cyclone (i.e., hurricane) status with the MSW estimated at 70 kts. By
1800 UTC the intensity had climbed to 90 kts, making Japhet the second
intense tropical cyclone of the season in the Southwest Indian Ocean.
At 0000 UTC on 1 March MFR and JTWC increased the intensity estimates
to 95 and 115 kts, respectively. The cyclone was then drifting southward
over the Mozambique Channel and still deepening. Japhet's peak
intensity was reached at 0600 UTC when the MSW reached 100 kts (10-min
avg), agreeing very well with JTWC's peak 1-min avg MSW of 115 kts. The
minimum CP estimated by MFR was 927 mb. Storm-force winds extended out
from the center about 70 nm, and gales reached outward 100 nm to the
north and 120 nm to the south. Japhet was essentially stationary at this
time, but a mid-level ridge over South Africa was forecast to strengthen
and eventually force the storm northward or northwestward.
By 0000 UTC on 2 March Tropical Cyclone Japhet's center was about
85 nm off the Mozambican coast and moving northwestward at 5 kts. The
storm had weakened slightly to 90 kts (105 kts per JTWC), and continued
weakening was forecast as Japhet approached the coast as a result of dry
air entrainment and less favorable poleward outflow. At 1200 UTC the
cyclone was just off the coast with both warning centers reporting the
intensity at 85 kts. By 1800 UTC Japhet was located just offshore about
80 nm south-southeast of Beira, Mozambique, and just about ready to move
inland. Tropical Cyclone Japhet made landfall at approximately 1930 UTC
just south of Vilanculos, Mozambique, with a MSW of around 80 kts (10-min
avg). Three hours before landfall Vilanculos reported a sustained wind
of 40 kts, gusting to 57 kts.
Japhet made landfall in Mozambique moving on a northwesterly track.
After moving ashore the weakening storm began to move in a more westerly
direction. At 1200 UTC on 3 March the center was located approximately
240 km northwest of Vilanculos, moving westward at 6 kts. This was the
final warning from JTWC, estimating the intensity at 55 kts--seemingly
a little high for a system which had been inland for almost 18 hours.
MFR's 1200 UTC warning reported the MSW at 35 kts, and that agency
issued its final bulletin on Japhet six hours later. That bulletin
noted that squally weather continued to affect waters in the southeastern
sector up to 400 km from the center.
C. Meteorological Observations
------------------------------
As noted above, Vilanculos, Mozambique, reported a sustained wind of
40 kts, gusting to 57 kts, around 02/1630 UTC. The only other report
I have available was from Ile Europa (22.3S, 40.3E) on 26 February during
the formative stages of Japhet. At 26/1200 UTC the storm was centered
approximately 70 nm northwest of the island, which reported sustained
east-southeast winds of 50 kts (10-min avg) and a MSLP of 1000 mb.
The respective MSW estimates from MFR and JTWC at that hour were 30 kts
and 35 kts. Such a strong wind 70 nm from the center does not seem
indicative of the strength of the circulation near the center, but rather
likely related to a strong gradient on the periphery of the storm due to
a strong HIGH passing to the south. (A thanks to Patrick Hoareau for
sending me the Ile Europa observation.)
D. Damage and Casualties
------------------------
Tropical Cyclone Japhet became another in a series of natural
disasters to inflict misery on the nation of Mozambique. As of 11 March
the death toll from the cyclone stood at 19 with most deaths due to
flooding. About 23,000 persons were rendered homeless in and around
the city of Vilanculos in Inhambane Province where Japhet initially
made landfall. Later, thousands more were displaced, losing their homes,
personal belongings, crops and livestock as the Save River, which flows
out of Zimbabwe, burst its banks and flooded towns and villages. In
Vilanculos about 95% of the brick houses had their roofs ripped off or
experienced damage to windows and doors. Water and electricity supplies
and telecommunications were also interrupted and several schools were
partially destroyed. Many roads in Inhambane and Manica Provinces were
either blocked by uprooted palms or else flooded.
Several articles on the effects of Tropical Cyclone Japhet in
Mozambique can be found at the following URL:
http://www.reliefweb.int/w/rwb.nsf/vLND>
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for February: 1 tropical LOW
1 tropical cyclone of gale intensity
1 severe tropical cyclone (hurricane)
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northwest Australia/Southeast Indian Ocean tropical cyclones are
the warnings and advices issued by the Tropical Cyclone Warning
Centres at Perth, Western Australia, and Darwin, Northern Territory.
References to sustained winds imply a 10-minute averaging period
unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Northwest Australia/Southeast Indian Ocean
Tropical Activity for February
------------------------------------------
Two tropical cyclones formed in waters off Western Australia during
February. The first, Fiona, was the first tropical cyclone of the
current season to be actually named by any of the Australian TCWCs,
although an unnamed system in January was determined in post-analysis
to have reached tropical cyclone status twice during its history. Fiona
became an intense tropical cyclone (10-min avg MSW 90 kts or greater)
but remained over the open waters of the Southeast Indian Ocean and
did not affect any land areas. Near the end of the month a much weaker
Tropical Cyclone Graham formed north of the Port Hedland area and moved
inland about 160 km southwest of Broome on the 28th.
A couple of other tropical LOWs deserve some mention. The first
formed approximately 125 nm northeast of the Cocos Islands on the 4th.
Gale warnings were issued by Perth for a couple of days in anticipation
that the system would strengthen, but there are no indications from
the text of the warnings that any actual gales, central or peripheral,
were observed. The LOW moved slowly westward and the final bulletin
from Perth at 0400 UTC on the 6th placed it about 200 nm west-northwest
of Cocos. There is a possibility that this system was the progenitor
of Tropical Storm Isha which formed west of 90E on 11 February. Another
weak tropical LOW was noted in the Perth Tropical Weather Outlooks on
the 24th and 25th of February. This system was located about 270 nm
southwest of Christmas Island on the 24th and was initially assessed to
have a moderate chance of developing into a tropical cyclone, but the
system subsequently weakened after the 25th.
SEVERE TROPICAL CYCLONE FIONA
(TC-14S)
4 - 13 February
-------------------------------------------------
A. Storm Origins
----------------
An area of convection developed and persisted on 3 February about
575 nm north-northwest of Port Hedland, Western Australia. Animated
multi-spectral imagery showed poorly-defined convection near a weak
LLCC, and a 200-mb analysis revealed good outflow over the disturbance.
The system drifted slowly westward on the 4th without much change in
organization until around 2000 UTC, when animated infrared imagery showed
an increase in convection near the LLCC. JTWC correspondingly upgraded
the potential for development to fair. An upper-level analysis showed
good diffluence and weak to moderate vertical shear. At 2200 UTC the
Perth TCWC issued the first gale warning on the developing tropical LOW,
placing the center approximately 625 nm north-northwest of Onslow in
Western Australia. JTWC issued a TCFA at 0500 UTC on 5 February, and
at 0700 UTC Perth named the system Tropical Cyclone Fiona, then located
approximately 350 nm east-southeast of Christmas Island. Fiona was
tracking westward with the MSW estimated at 40 kts (10-min avg).
B. Track and Intensity History
------------------------------
JTWC issued their first warning on Fiona (TC-14S) at 1200 UTC on
5 February, estimating the 1-min avg MSW at 35 kts. CIMSS data indicated
good outflow aloft and a weak vertical shear environment, so conditions
appeared favorable for Fiona to strengthen significantly. The cyclone
was forecast to track generally westward under the steering influence
of a ridge to the south. Fiona intensified steadily--at 06/1200 UTC
both JTWC and Perth were estimating the intensity at 55 kts. The remarks
in the JTWC warning well illustrate the vagaries of cyclone intensity
estimation by remote sensing. At that hour the CI estimates available
to JTWC ranged from 35 to 65 kts.
Fiona continued moving west-southwestward as it strengthened. Perth
upgraded the storm to severe tropical cyclone (hurricane) status at
0400 UTC on 7 February when located approximately 125 nm southeast of
Christmas Island. (At 1200 UTC JTWC also upgraded Fiona to hurricane
intensity with 75-kt winds 1-min avg.) A 07/2320 UTC SSM/I pass depicted
an eye embedded within partial concentric convective bands. Perth upped
the intensity to 100 kts at 08/0400 UTC and to the peak intensity of
105 kts at 1000 UTC. Gales reached outward 125 nm from the 16-nm
diameter eye while the radius of 50-kt winds was estimated at 45 nm.
The minimum CP estimated by Perth was 930 mb. At the time of its peak
intensity, Fiona was located roughly 300 nm east-southeast of the Cocos
Islands, moving west-southwestward at 10 kts. (JTWC's peak 1-min avg MSW
for Fiona was 100 kts, somewhat less than the 120 kts implied by Perth's
105-kt 10-min avg intensity.)
By 09/0000 UTC Fiona was located about 260 nm southeast of Cocos,
temporarily moving toward the southwest at 11 kts. Recent microwave
imagery showed some drier air to the south of the cyclone. By 1000 UTC
Perth had brought the intensity down to 90 kts (JTWC was still reporting
100 kts 1-min avg MSW). Deep convection had weakened somewhat and the
eye had become cloud-filled. Cooler air associated with a migratory
high-pressure system was apparently affecting the system. Perth reduced
the MSW to 80 kts at 09/1600 UTC where it remained pegged for over
24 hours. Animated enhanced infrared and microwave imagery around 0000
UTC on the 10th revealed that a 25-nm irregular eye had reformed, but
animated water vapor imagery showed cooler and drier air beginning to
wrap into the cyclone from the south. At 1200 UTC Fiona's center was
located about 350 nm southwest of the Cocos Islands, moving westward
at 8 kts.
Fiona began to turn southwestward as it neared the 90th meridian.
A deepening shortwave trough was forecast to weaken the subtropical ridge
to the south of the cyclone. At 1000 UTC on 11 February Fiona was
located approximately 500 nm southwest of Cocos, moving slowly south-
westward with deep convection weakening. Perth's and JTWC's estimated
MSW values at that hour were 75 and 80 kts, respectively. By 12/0400
UTC Fiona had weakened to below hurricane intensity. The storm by this
time was about 600 nm southwest of Cocos and moving due southward at
around 8 kts. Tropical Cyclone Fiona recurved along the 91st meridian
between 1600 and 2200 UTC on the 11th and thence began moving south-
southeastward. The storm began to weaken rapidly as the 12th progressed,
and by 13/0000 UTC had lost all its associated deep convection with
the LLCC decoupling from the mid-level circulation. JTWC issued their
final warning at 13/0000 UTC, and Perth followed suit with their final
warning at 0400 UTC placing the center about 650 nm south-southwest of
the Cocos Islands.
According to an e-mail received from Carl Smith, much of the moisture
from Fiona and Tropical Storm Isha west of 90E was sucked into a trough
associated with a frontal system and transported east-southeastward.
Fiona's remnant eventually passed south of southwestern Western Australia
before recurving into the Great Australian Bight, and the residual LOW
from Isha cut across the southwestern corner of the continent to meet
it. The whole disorganized mess then moved northeastward overland
through South Australia and New South Wales and up the coast into
Queensland and the southern Coral Sea. All this influx of moisture
could have been a factor in the formation of Tropical Cyclone Erica
there in early March.
C. Rainfall in Eastern Australia
--------------------------------
The Eyre Peninsula and Adelaide recorded more rain in 24 hours than
they had in the previous two years. The New South Wales outback then
experienced a good soaking, causing major flooding events in several
towns, including Tamworth. The central New South Wales coast next
experienced major flooding which closed the Pacific Highway, and finally
the heavy rains reached the Gold Coast of Queensland. Carl stated that
Stephens (where he lives) had had over 240 mm of rain within a 24-hour
period. Over 100 houses along the Gold Coast were damaged due to the
torrential rains and attendant flash flooding and landslips. (A special
thanks to Carl for sending me the above information.)
D. Damage and Casualties
------------------------
There are no known casualties or damage resulting from the tropical
cyclone stage of Fiona's life.
(Report written by Gary Padgett)
TROPICAL CYCLONE GRAHAM
(TC-20S)
26 February - 1 March
-------------------------------------------
A. Storm Origins
----------------
JTWC issued a STWO at 0400 UTC on 23 February, noting that a
persistent area of convection which had been located over land for the
previous week had reached a position near the northwestern coast of
Australia. A surface circulation was located approximately 210 nm east-
northeast of Port Hedland. The LLCC was still over land, but the
primary associated convection had moved over open water. A 200-mb
analysis indicated that the disturbance was equatorward of a ridge axis
under easterly vertical shear. The development potential was rated as
fair, but was downgraded to poor on the 24th based on a less-organized
appearance in satellite imagery.
Around 2100 UTC on 25 February the LOW was located approximately
160 nm north of Port Hedland. Animated visible imagery depicted sporadic
weak convection in the vicinity, and a 25/0947 UTC QuikScat pass
indicated a broad LLCC with the strongest winds on the equatorward side
in a band along latitude 16S. The system was beneath moderate easterly
vertical shear and the potential for development was still rated as poor.
The Perth TCWC began issuing gale warnings on the LOW at 0100 UTC on the
26th, the center of the LOW then being located about 225 nm north-
northeast of Port Hedland. West to northwest winds of 35-40 kts were
occurring in the monsoon trough well north of the center of the LOW.
The system remained quasi-stationary on the 26th while slowly becoming
better organized. JTWC issued a TCFA at 27/0230 UTC--animated visible
imagery showed improving organization of the deep convection near the
LLCC while QuikScat data revealed enhanced westerly winds equatorward of
the LLCC. An upper-air analysis indicated that vertical shear had
diminished while outflow remained good. At 0700 UTC on 27 February the
Perth TCWC upgraded the LOW to Tropical Cyclone Graham with 45-kt winds
(10-min avg), located approximately 200 nm northeast of Port Hedland.
B. Track and Intensity History
------------------------------
JTWC issued their first warning on Graham (TC-20S) at 1800 UTC on
the 27th but only estimated the MSW (1-min avg) at 30 kts. The system
was forecast to drift southeastward under the steering influence of a
weak mid-level ridge to the north. By 0600 UTC on the 28th Graham's
center was located about 180 nm northeast of Port Hedland, moving
southeastward at only 3 kts. JTWC had upped the intensity to 35 kts
while Perth had lowered their 10-min avg MSW estimate slightly to
40 kts, although this was increased back to 45 kts six hours later.
Tropical Cyclone Graham's center crossed the Western Australian
coastline near the 80 Mile Beach at approximately 28/1400 UTC. Synoptic
data in the vicinity indicated sustained winds of 38 kts (presumably
a 10-min avg). By 1600 UTC the weakening Graham was inland about
165 km south-southwest of Broome. The system continued to weaken and
the final bulletin from Perth was issued at 0400 UTC on 1 March. JTWC
likewise issued their final warning on Graham at 01/0600 UTC.
C. Meteorological Observations
------------------------------
The following table lists a few 24-hour rainfall totals associated
with Graham which exceeded 100 mm:
Station Period Amount
--------------------------------------------------------------
Derby 26 Feb/0100 UTC - 27 Feb/0100 UTC 157 mm
Curtin RAAF 26 Feb/0100 UTC - 27 Feb/0100 UTC 148 mm
Dampier Downs 27 Feb/0100 UTC - 28 Feb/0100 UTC 131 mm
Shelamar 28 Feb/0100 UTC - 01 Mar/0100 UTC 142 mm
Warrawagine 28 Feb/0100 UTC - 01 Mar/0100 UTC 115 mm
Telfer 28 Feb/0100 UTC - 01 Mar/0100 UTC 175 mm
The highest sustained wind observation apparently was SSE/45 kts from
Mandora at 28 Feb/0200 UTC. Broome reported W/29 kts, gusting to 40 kts,
at 01 Mar/0100 UTC. Port Hedland's highest wind was SSE/28 kts, gusting
to 40 kts, at 01 Mar/0300 UTC, while West Roebuck recorded west winds of
21 kts, gusting to 40 kts, at 28 Feb/1700 UTC. And finally, Telfer
reported sustained winds of SE/38 kts, gusting to 48 kts, at 28 Feb/1800
UTC. (A special thanks to Matthew Saxby for sending me the above
observations.)
D. Damage and Casualties
------------------------
I have learned of no casualties or significant damage resulting from
Tropical Cyclone Graham.
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for February: 1 tropical cyclone **
1 hybrid LOW
** - Remnants of Tropical Cyclone Beni from east of 160E briefly
re-intensified off the Queensland coast in early February. Beni
was covered in the January summary.
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northeast Australia/Coral Sea tropical cyclones are the warnings
and advices issued by the Tropical Cyclone Warning Centres at
Brisbane, Queensland, and Darwin, Northern Territory, and on very
infrequent occasions, by the centre at Port Moresby, Papua New
Guinea. References to sustained winds imply a 10-minute averaging
period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Northeast Australia/Coral Sea
Tropical Activity for February
------------------------------
As the month of February opened, the weak remnant LOW of former
intense Tropical Cyclone Beni was moving westward across the southern
Coral Sea. A band of gales of 40-45 kts began to develop well south
of the center and the Brisbane TCWC began issuing gale warnings. Early
on the 4th it appeared that the system might be turning into an intense,
vertically-stacked hybrid just off the Queensland coast. So the system
was re-upgraded to Tropical Cyclone Beni for a 12-hour period on
4 February, but the vertical shear increased and proved to be too much
for Beni to overcome and the low-level center became decoupled from the
gales. The full history of Tropical Cyclone Beni, including its brief
redevelopment in Australian waters, can be found in the January tropical
cyclone summary.
The only other system for which Brisbane issued warnings in February
was a LOW which formed just off the Queensland coast near Townsville on
the 26th. This system never developed any organized convective clouds
near its center and was more of a hybrid LOW than a tropical system.
Nonetheless, the system deepened some on the 28th, requiring the issuance
of gale warnings. At 28/0000 UTC the LOW was centered approximately
250 nm east of Rockhampton, moving south-southeastward. Gales of
35-40 kts had developed by 1200 UTC and continued on into the early
hours of 1 March. The final gale warning, issued at 0430 on 1 March,
indicated that winds had dropped below gale force with the system then
located about 300 nm east-northeast of Brisbane, still moving south-
eastward.
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for February: 2 tropical depressions **
1 tropical cyclone of hurricane intensity
** - One of these was not designated with the normal numbering system
employed by Nadi for tropical depressions and may have been
considered more of a hybrid or subtropical system.
Sources of Information
----------------------
The primary sources of tracking and intensity information for
South Pacific tropical cyclones are the warnings and advisories
issued by the Tropical Cyclone Warning Centres at Nadi, Fiji (for
waters north of latitude 25S), and Wellington, New Zealand (for
waters south of latitude 25S). References to sustained winds imply
a 10-minute averaging period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Southern Hemisphere
centres' coordinates by usually 40-50 nm or more. The JTWC warnings
are also the source of the 1-minute average maximum sustained wind
values included in the tracks file. Additionally, information
describing details of satellite imagery and atmospheric circulation
features included in the narratives is often gleaned from the JTWC
warnings.
South Pacific Tropical Activity for February
--------------------------------------------
In contrast to January, when three tropical cyclones formed--two of
them intense, February was much quieter with only one named cyclone.
That system, Tropical Cyclone Dovi, became a very intense storm well
east of the Dateline, but fortunately did not seriously affect any
island communities. There were a few other systems which need to be
mentioned, however. A long-lived weak system during the first week of
February was designated as Tropical Depression 08F by the Nadi TCWC.
The system was first identified as a tropical disturbance on 30 January
when located about 200 nm north of American Samoa. The system remained
quasi-stationary for a few days, but on 3 February was relocated several
hundred miles to the south to a position about 175 nm east-southeast of
Pago Pago, American Samoa. The LOW drifted slowly eastward for a couple
of days, but on the 5th was relocated once more back to the west to a
position just southwest of Samoa. Prior to this the system had been
referred to as only a tropical disturbance, but at 05/0600 UTC Nadi
upgraded it to tropical depression status. TD-08F subsequently moved
slowly westward and by the 9th had weakened a couple hundred miles north
of Fiji. Based on the Fiji Tropical Disturbance Summaries, sustained
winds in this system likely did not exceed 15 kts.
Another rather long-lived system was designated as Tropical
Disturbance 10F by Fiji, but was never referred to as a tropical
depression. This system was first identified well north of Fiji, west
of Niulakita and north of Rotuma, on the 15th. The LOW drifted generally
westward and was last mentioned on the 21st when located in the Solomon
Island chain north of the Santa Cruz Islands. A final system referenced
in the Nadi Tropical Disturbance Summaries formed on the 18th about
350 nm east-northeast of Rarotonga in the Southern Cook Islands. This
system was referred to simply as a LOW initially; then, beginning on
20 February, was labeled Depression L1. Given its latitude (20S) and
the unusual designation, it seems likely that this system was not a
purely tropical LOW but more of a hybrid. The system moved southeast-
ward and was last mentioned at 2100 UTC on the 21st when located about
475 nm south-southeast of Tahiti. (Note: Tracks for Depression L1 and
Tropical Depression 08F were included in the February cyclone tracks
file, but not for Tropical Disturbance 10F.)
The following report on intense Tropical Cyclone Dovi was written
by Simon Clarke of Cleveland, Queensland. A special thanks to Simon
for his assistance.
TROPICAL CYCLONE DOVI
(TD-09F / TC-15P)
5 - 12 February
-----------------------------------------
A. Storm Origins
----------------
Dovi was the sixth tropical cyclone of the 2002/2003 South Pacific
Tropical Cyclone Season and, following the trend set by Zoe and Beni,
was to become yet another very intense storm. Tropical Cyclone Dovi
was one of the most intense cyclones on record in the South Pacific
east of the Dateline, exceeded in recent years only by Tropical Cyclone
Ron in January, 1998.
Dovi was first identified as a quasi-stationary circulation centre
located within the South Pacific Convergence Zone in the vicinity of
the Northern Cook Islands (approximately 460 nautical miles to the
east-northeast of Pago Pago, American Samoa). At the time, the system
was located in a favourable outflow environment to the east and north,
with improving outflow elsewhere, weak to moderate vertical wind
shear, and warm sea surface temperatures of approximately 30 C.
The circulation initially moved to the southeast at about 8 knots
while slowly showing signs of improved organization with convection
increasing and cooling around the LLCC. Development of the system was
to be fairly rapid, and at 2100 UTC on 5 February, Fiji upgraded the
system to Tropical Depression 09F. The central pressure of the
tropical depression quickly fell to 995 hPa, and within three hours
TD-09F was upgraded to tropical cyclone status and named Dovi. At this
time, the mid-level ridge to the east of the cyclone was steering the
storm on a southerly path.
B. Track and Intensity History
------------------------------
The mid-level ridge ultimately pushed Dovi onto a south-
southwesterly path which was sustained throughout much of its life.
Initially, Dovi was underneath the 250-hPa ridge axis with relatively
minimal shear and continuing high SSTs. With improving environmental
conditions, Dovi continued to steadily intensify as it moved toward the
southwest at approximately 8 knots. By late on 6 February the cyclone
had reached hurricane status.
Dovi continued to intensify at a fairly rapid rate as a 250-hPa
anticyclone to the west moved closer to the cyclone. By 07/2007 UTC
Dovi had developed a distinct eye. The peak intensity was reached
at 08/1800 UTC with Dovi located near 19.4S, 167.8W, or approximately
350 nautical miles south-southeast of Pago Pago. At this time Dovi's
central pressure was estimated at 920 hPa and the storm was producing
maximum 10-minute average winds of 110 knots close to its centre.
(Editor's Note: JTWC's peak 1-minute average MSW for Dovi was
130 knots--in good agreement with Nadi's estimate.)
The demise of Dovi was to commence as a consequence of increasing
vertical wind shear coupled with cooler SSTs. The storm was driven
toward the south along the western edge of the poleward-oriented mid-
level ridge and gradually lost its convective structure. By 1400 UTC
on 10 February, the convective tops had become sheared to the south-
east and the LLCC was displaced to the northwestern edge of the deep
convection. Outflow in the western and southern quadrants remained
good but was deteriorating elsewhere. Dovi had weakened to a 980 hPa
storm by this time with maximum 10-minute average winds of 55 knots.
Movement was to the south-southeast at 6 knots. Extratropical
transition was complete by 11/0138 UTC with the storm near 26.0S,
169.0W (or about 600 nautical miles southwest of Rarotonga). By this
time, the ridge building to the south began to steer the remains of the
storm slowly toward the south-southwest. The MetService based in
Wellington, New Zealand, continued to issue warnings for the gales
associated with the remnant of Dovi for a further 48 hours.
C. Meteorological Observations
------------------------------
I was almost ready to mail this summary when I received a report
on Dovi from Alipate Waqaicelua, Chief Forecaster at the Nadi TCWC.
There was not really anything new to include regarding the synoptic
history of Tropical Cyclone Dovi, but Alipate's report did include
one observation from Niue: "Niue only experienced strong winds (below
gale) and very rough seas. There was neither structural damage nor
loss of life. Damage to trees and vegetation was minor. The lowest
pressure recorded was at 09/0125 UTC with 992.9 hPa. Maximum gust
recorded was 35 knots at 08/2200 UTC and the maximum sustained wind
was 21 knots at 08/2200 UTC." (A thanks to Alipate for sending the
report.)
D. Damage and Casualties
------------------------
Tropical Cyclone Dovi spent its entire life at sea. Strong and
gusty winds and heavy swells were reported from the Southern Cook
Islands and Niue. Aside from damage to banana plantations on
Palmerston Island, no significant damage was reported.
(Report written by Simon Clarke)
*************************************************************************
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]
*************************************************************************
*************************************************************************
|
Document: summ0302.htm
Updated: 27th December 2006 |
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