[Index]
Monthly Global Tropical Cyclone Summary March 2000
[Summaries and Track Data] [Prepared by Gary Padgett]
| Tropical
Cyclones
[Index] |
Monthly Global Tropical Cyclone Summary March 2000 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
MARCH, 2000
(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.)
***********************************************************************
MARCH HIGHLIGHTS
--> Tropical Cyclone Steve almost circumnavigates Australia
--> South Pacific east of Dateline sees more activity
--> Another major South Indian Ocean cyclone develops
***********************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for March: No tropical cyclones
***********************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for March: No tropical cyclones
***********************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for March: No tropical cyclones
***********************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for March: 1 tropical depression **
** - No warnings were issued on this system by JTWC, but IMD at one
point referred to it as a cyclonic storm.
North Indian Ocean Activity for March
-------------------------------------
The only tropical cyclone activity in the Northern Hemisphere during
March occurred late in the month in the Bay of Bengal. Since the
narrative below gives fairly in-depth coverage of this system, there is
no point in being redundant here. In keeping with a practice I
initiated last year, I chose to designate the storm with a letter of
the Greek alphabet (in this case "Iota") since there is fairly strong
evidence there was an unnumbered/unnamed tropical system of gale force
for which no warnings were issued (at least in its latter stages) by
any warning agency. As noted below, I am indebted to Julian Heming
of the UK Meteorological Service for calling attention to this system,
and to Roger Edson of the University of Guam for performing an analysis
and providing a track for the cyclone.
Tropical Cyclone "Iota"
25 March - 1 April
-----------------------
One thing is certain--there was disturbed weather in the Bay of
Bengal during the closing days of March. Beyond that it isn't at all
certain just what went on. The Indian Meteorological Department (IMD)
carried the system as a depression for three days and referred to it
as a cyclonic storm (i.e., a tropical storm) on 30 Mar. JTWC never
issued any warnings but two Formation Alerts were issued at 0430 UTC
on both 29 and 30 Mar. There was some disagreement between the two
centers regarding the exact location, but both generally agreed that
the LLCC eventually turned north or north-northeastward. (It should
be pointed out that for the NWP basin only, JTWC normally initiates
tropical depression warnings when a system is analyzed to have a MSW
(1-min avg) of 25 kts, but in the other basins warnings are not
normally initiated until the system reaches 35 kts, or else has a very
high potential to reach tropical storm intensity within the next 36-48
hours. This system would likely have been carried as a tropical
depression in the NWP basin.)
But around mid-April Julian Heming of the UK Meteorological
Service send around a visible satellite picture taken at 0300 UTC on
1 Apr which showed what looked like a quite well-organized tropical
storm with possibly an eye making landfall on the southeastern coast
of India. Furthermore, this was exactly what the UK model had been
predicting would happen. Roger Edson of the University of Guam
performed an analysis of this system and concluded that it was a midget
tropical cyclone of possibly near-hurricane force, and that it was not
a new development but a redevelopment around the old LLCC from the
system being mentioned by IMD and JTWC a few days earlier.
Roger's track picks the system up the earliest (25/0000 UTC),
locating a weak center very deep in the tropics (4.0N, 88.5E) about
550 nm east-southeast of Colombo, Sri Lanka. JTWC first mentioned
the area in their daily STWO at 1800 UTC on 26 Mar, indicating that
an area of convection was located about 240 nm west-northwest of
Sumatra with a possible associated LLCC (as indicated by a recent
QuikScat pass). IMD first mentioned a low-pressure area at 0600 UTC
on the 27th, located about 625 nm east-northeast of Colombo. IMD's
coordinates show the system never getting further west than 88.0E
(at 29/0300 UTC) and then curving back to the north-northeast.
JTWC issued the first of two Formation Alerts at 29/0430 UTC, placing
the center near 10.6N, 87.8E. This is very near Roger's 29/0000 UTC
position of 10.5N, 87.5E.
JTWC's second Formation Alert at 30/0430 UTC placed the center near
14.1N, 89.5E. This location was about 90 nm to the south-southwest of
IMD's position at 0300 UTC in which they referred to the system as a
"cyclonic storm" (i.e., of gale force). However, this position is
nowhere near Roger's 30/0000 UTC coordinates of 11.5N, 85.5E. In an
e-mail to Julian Heming (which I received a copy of) Roger insists
that there was only one circulation in the NIO during the period in
question. He could follow it each day in the scatterometer data.
The convection eventually sheared off to the northeast, and apparently
JTWC and IMD assumed the LLCC went with it, but according to Roger,
the LLCC lagged behind around 10N, becoming elongated for awhile, then
reorganizing into a more well-defined circulation.
A sequence of satellite imagery was provided by Julian beginning at
31/0600 UTC (visible and infrared) and continuing with infrared imagery
through 1200 UTC on 1 Apr. At 31/0600 UTC a small convective cloud
mass was apparent off the southeastern Indian coast. At 31/0000 UTC
Roger's track assigns a MSW of 45 kts to the system which was located
about 225 nm east of Madras. The area of convection is seen
subsequently to move westward toward the coast of India. Convection
appeared to have weakened some at 1800 UTC but had flared back up by
2100 UTC. Roger believes the system reached a peak intensity of
around 60 kts at 0000 UTC on 1 Apr when it was centered about 100 nm
southeast of Madras. A visible image at 01/0300 UTC clearly shows
the system making landfall between Madras and Pondichery. The image
shows a "dimple" which Julian thought might represent an eye. Roger
feels that although the feature may have been an eye, he cannot
substantiate it.
By 0600 UTC the center was inland and beginning to weaken, and by
1200 UTC most of the deep convection had dissipated near the center,
although a swirl could still be discerned in the infrared imagery.
NOTE: Roger Edson points out that his analysis of this system was
not performed with the same degree of precision he normally used while
still a forecaster at JTWC. It was based on available scatterometer
data and TRMM, infrared, and visible satellite imagery, but these did
not constitute a complete set. The coordinates are given to the
nearest one-half degree of latitude and longitude. Also, Roger points
out that a good bit of his analysis was based upon the newer QuikScat
scatterometer which is not yet a "proven" sensor--i.e., it could have
a high or low bias.
A special thanks to Roger and to Julian Heming for the information
and satellite imagery they provided for this interesting system.
***********************************************************************
SOUTH INDIAN OCEAN (SIO) - South Indian Ocean West of Longitude 90E
Activity for March: 1 tropical disturbance
1 tropical depression
1 intense tropical cyclone
The primary sources of information upon which the narrative is based
are the warnings issued by the TCWC on La Reunion Island, associated
with Meteo France, and which is the RSMC for the South Indian Ocean
basin. However, cyclones in this region are named by the sub-regional
centres on Mauritius and Madagascar with longitude 55E as the dividing
line between their respective areas. La Reunion only advises these
centres regarding the intensity of tropical systems. References to
sustained winds should be understood as meaning a 10-min averaging
period unless otherwise stated. In the accompanying tracks file
some position comparisons have been made with JTWC's positions, and
warnings from JTWC were used as a source of 1-min avg MSW estimates.
Also, the comments about satellite imagery and other sources of data
such as SSM/I and TRMM were obtained for the most part from the JTWC
warnings.
South Indian Ocean Activity for March
-------------------------------------
As the month of March opened Tropical Storm Gloria was making
landfall in extreme northern Madagascar with the remnants drifting
across the island over the next several days. Rainfall from the
storm led to significant flooding with almost 150 lives lost. (See
the February summary for the history of Tropical Storm Gloria.)
Also, as the month began two more tropical systems were showing signs
of development farther east in the South Indian Ocean. The first of
these was a tropical depression which formed just west of 90E on
1 Mar. This system was referred to as Tropical Depression #9 by
MFR and as TC-17S by JTWC. MFR and JTWC both initiated bulletins on
the LOW on 1 Mar when it was located about 525 nm west of Cocos Island.
MFR upgraded the disturbance to a tropical depression (10-min avg MSW
< 27 kts) on 2 Mar at 0600 UTC. The depression drifted very slowly
generally westward and then southwestward over the next several days,
reaching a point about 700 nm southeast of Diego Garcia by 0000 UTC
on 5 Mar. The system was weakening and JTWC wrote its last warning,
and La Reunion downgraded it back to a tropical disturbance but
continued to follow it for another couple of days. The system reversed
its heading and moved slowly on an easterly track, briefly regaining
tropical depression status on 6 Mar but weakening again on the 7th.
MFR wrote their final bulletin at 1200 UTC with the weakening center
about 850 nm southeast of Diego Garcia. MSW estimates from both
warning centers did not exceed 30 kts for this depression.
Another system was designated as Tropical Disturbance #10 by La
Reunion on 2 and 3 Mar. This disturbance formed about 250 nm south-
southeast of Diego Garcia and remained quasi-stationary for most of
its short life with perhaps a slight southward drift. The highest
10-min avg MSW estimated by MFR was only 25 kts with perhaps some
winds reaching 30 kts locally well away from the center. A track
is given for this system in the accompanying tracks file since it
was assigned Dvorak numbers of T2.0 and would likely have been
considered a tropical depression in some other basins. JTWC never
issued any warnings or Formation Alerts on this LOW, although it was
given a Fair development potential at one point.
The major tropical development of the month in the Southwest Indian
basin was Tropical Cyclone Hudah which formed on 25 Mar just east of
the boundary with Perth's AOR. Since the rapidly developing system
was leaving their territory, Perth did not name the cyclone and it
was named Hudah as it crossed 90E into the Mauritius/La Reunion AOR.
By month's end Hudah had strengthened into an intense cyclone and was
drawing closer to northern Madagascar.
Tropical Cyclone Hudah (TC-21S / SIO #12)
24 March - 9 April
------------------------------------------
Intense Tropical Cyclone Hudah had many affinities with February's
great Tropical Cyclone Leon-Eline. Both formed in the Southeast
Indian Ocean in Perth's AOR, moved on fairly straight westerly tracks
across the entire South Indian, struck Madagascar as intense tropical
cyclones, weakened, then regained intensity in the Mozambique Channel
and made final landfalls in Mozambique. Hudah was smaller in areal
extent than Eline but was considerably more intense at its peak and
at its landfall in Madagascar. However, Hudah did not become as
intense in the Channel as Eline did and was weakening some when it
made landfall in northern Mozambique. These two cyclones represent
what could be regarded as the South Indian Ocean's counterpart to
the Atlantic's famous "Cape Verde hurricanes"--great storms which
form in the eastern reaches of the respective basins and manage to
travel on westerly courses for thousands of miles to wreak havoc on
islands and continents at the western sides of the oceans.
A Tropical Weather Outlook issued by JTWC on 22 Mar at 1800 UTC
noted that an area of convection had formed approximately 370 nm
southeast of Christmas Island. Animated satellite imagery showed
disorganized weak convection associated with a broad circulation
embedded in the monsoon trough. A CIMSS analysis revealed weak
vertical shear with good outflow aloft. The disturbance was given
a Fair development potential on 23 Mar as the LLCC appeared to be
better defined with persistent though still disorganized convection.
At 1800 UTC the LLCC was located roughly 240 nm south-southeast of
Cocos Island. Vertical shear had increased slightly but the potential
for development was still rated Fair.
JTWC issued a Formation Alert at 0030 UTC on 24 Mar. The system
was by then southwest of Cocos Island and moving west at 15 kts with
winds estimated at 20-25 kts. Moderate convection was building around
the LLCC with animated water vapor imagery indicating improved upper-
level outflow and decreasing vertical shear. At 1200 UTC JTWC issued
its first warning on TC-21S with the center located approximately
300 nm west-southwest of Cocos Island. Animated visible and infrared
imagery depicted a small system with an areal extent of 100 nm. A
CDO appeared to be developing over the LLCC with a banding feature
in the northwest quadrant. The 200-mb ridge axis was located just
south of the system.
The Perth TCWC had begun issuing warnings on the LOW at 24/1000 UTC.
As the system approached 90E early on 25 Mar it began to show signs
of rapid intensification. Dvorak ratings on the system from JTWC
increased from T=2.5 at 0351 UTC, to T=3.5 at 0620 UTC, and to T=4.5
at 1215 UTC. Perth also rated the storm at T=4.5 at 0830 UTC. JTWC
assigned a MSW (1-min avg) of 55 kts at 0600 UTC and 70 kts at 1200
UTC. 200-mb analysis indicated good divergence over the system with
the ridge axis just to the south. Perth, in its final warning,
indicated that the LOW had reached tropical cyclone intensity, but as
the system was about to leave their AOR, did not assign a name. The
developing storm was named Tropical Storm Hudah by the Mauritius
Meteorological Service as soon as it crossed 90E at a point almost
500 nm west-southwest of Cocos Island.
The radius of 50-kt winds was only 20 nm while gales extended out
90 nm to the south and 65 nm elsewhere (this information from JTWC's
warning). A small, cloud-filled eye was evident by 25/1200 UTC with
the eye half-enclosed by a deep convective wall in the northern
quadrant. By 1800 UTC the intensification trend had leveled off some
with cloud tops having warmed and the warm eye no longer evident.
There was good divergence still located over Hudah, however, and the
storm maintained its intensity of 55 kts (10-min avg) from Reunion
and 65 kts (1-min avg) from JTWC. A weak eye was apparent in a SSM/I
pass at 26/0338 UTC with a later pass indicating a convective band in
the northern quadrant. JTWC maintained Hudah's intensity at 65 kts
during the 26th while MFR (Reunion) increased their 10-min avg wind
estimate to 60 kts at 1200 UTC.
Hudah intensified on 27 Mar with satellite imagery revealing a
7-nm wide eye by 0600 UTC. MFR upgraded Hudah to a tropical cyclone
(hurricane) with 70-kt winds at 1200 UTC when the storm was centered
about 650 nm southeast of Diego Garcia. (JTWC's 1-min MSW estimate
had reached 80 kts at 0600 UTC.) By 1800 UTC Dvorak numbers were a
solid T5.0 and JTWC increased their MSW estimate to 90 kts. SSM/I
data indicated a well-developed symmetric eye with a significant
banding feature over the southern half of the cyclone. The deepest
convection was to be found in the western half of the eyewall. Hudah
was still a small cyclone with hurricane force winds confined to an
area within about 20 nm or less from the center. Gales likely did not
extend out any further than 90-100 nm from the eye to the south, and
lesser distances in the other quadrants.
Tropical Cyclone Hudah continued to move on a generally westward
course across the central South Indian Ocean, moving a little to the
west-southwest on 28-29 Mar before resuming a straight westerly track
on 30 Mar. The cyclone maintained good outflow with the upper-level
anticyclone intensifying a bit on 28 Mar. MFR increased the maximum
10-min avg wind estimate to 80 kts at 28/0000 UTC and to 85 kts by
0600 UTC on the 29th. JTWC reported the MSW (1-min avg) at 100 kts
at 28/1200 UTC but brought it back down to 90 kts twelve hours later.
Infrared and water vapor imagery revealed well-defined outflow channels
to the north and east of the LLCC with the most significant convective
band over the southern part of the system.
Hudah passed about 550 nm south of Diego Garcia at 29/0000 UTC. The
anticyclone aloft over the cyclone showed some signs of weakening and
enhanced infrared imagery on 30 Mar showed Hudah to be undergoing some
slight shearing from the southwest. MFR lowered the intensity to
70 kts at 30/1800 UTC while JTWC decreased the MSW estimate to 80 kts.
Hudah remained a small system with the radius of gales to the south
not much more than 100 nm. The storm passed about 150 nm to the north
of Rodrigues Island around 0600 UTC on 31 Mar, still moving to the
west. By the 31st the cyclone was showing some improved convective
organization along with a decrease in the shearing; consequently, the
maximum winds began to increase once more. JTWC upped their MSW
estimate to 100 kts at 1200 UTC with animated visible imagery revealing
a 20-nm diameter eye. Likewise, MFR increased the maximum 10-min avg
wind estimate to 100 kts in their 1800 UTC warning.
A TRMM pass at 31/2047 UTC depicted an intense, symmetric system
with a 24-nm wide cloud-free eye. SSM/I data showed the eyewall
completely surrounding the LLCC. Based on satellite intensity
estimates of 115 and 127 kts, JTWC increased their MSW estimate to
120 kts at 0000 UTC on 1 Apr when Hudah was centered approximately
225 nm northeast of Mauritius. So, as the month of April opened,
Tropical Cyclone Hudah was an already intense and still intensifying
storm moving steadily toward what would be a devastating strike on
northern Madagascar. The remainder of Hudah's history will be
covered in the April summary.
***********************************************************************
AUSTRALIAN REGION (AUG) - From Longitude 90E Eastward to Longitude 160E
Activity for March: 1 gale center (non-tropical)
3 tropical LOWs **
2 tropical cyclones ++
1 severe tropical cyclone (hurricane)
** - One of these was named Tropical Cyclone Tessi on 1 April and will
be covered in the April summary.
++ - One of these was Tropical Cyclone Steve which began in February.
The primary sources of information for Australian Region tropical
cyclones are the warnings and bulletins issued by the three TCWCs
at Perth, Darwin, and Brisbane. Information gleaned from JTWC's
warnings is used as a supplement for times when it was impossible to
obtain Australian bulletins and for comparison purposes. References
to sustained winds should be understood as being based on a 10-min
averaging period unless otherwise noted.
Matthew Saxby, a tropical cyclone enthusiast from Queanbeyan, New
South Wales, Australia, typed up the tracks for the cyclones and LOWs
in the Australian Region. Also, Carl Smith, another dedicated tropical
cyclone enthusiast from the Gold Coast of Queensland, sent a report he
had written for Tropical Cyclone Steve, and Lori Chappel of the Darwin
TCWC sent me a report on Cyclone Steve's passage through Darwin's
AOR. Most of the information on Steve presented below is based upon
these reports. A special thanks to Lori, Carl and Matthew for
sending the information to me.
A description of the Australian Cyclone Severity Scale can be found in
Chris Landsea's FAQ on HRD's website:
http://www.aoml.noaa.gov/hrd/tcfaq/tcfaqD.html#D2>
on Michael Bath's Australian Severe Weather site:
http://australiansevereweather.com/cyclones/history.htm>
or on the Australian Bureau of Meteorology's official website:
http://www.bom.gov.au/info/cyclone/>
Click on the link 'Cyclone Severity Categories'
Carl Smith has a website on which he has placed his full reports on
the various cyclones in the Australian Region this season, as well as
map animations which he has created for the storms. The URL is:
http://www.ace-net.com.au/~carls/current.htm>
Links to various reports and map animations can be found under the
link 'TC Reports & Map Animations'.
Australian Region Activity for March
------------------------------------
The Australian Region as a whole experienced a fairly active month
with regard to tropical cyclone activity. Only two cyclones were
named, but one holdover from February (Steve) continued active for
over a week into the month, and a tropical LOW off the Queensland coast
at the end of the month was named as Tropical Cyclone Tessi on 1 April.
There were also several tropical LOWs in the Queensland region which
failed to develop into cyclones. The first was a very short-lived LOW
on 3 Mar for which Brisbane issued only one warning. The only warning
(issued at 0600 UTC) located the LOW's center about 525 nm east of
Townsville and gales were forecast to develop, but six hours later the
gale warning was cancelled as the LOW had weakened. No track is given
for this system in the accompanying cyclone tracks file.
A second tropical LOW formed on 14 Mar about 600 nm east-northeast
of Cooktown. This LOW moved southwestward toward the Queensland coast
and was forecast to develop into a tropical cyclone, but the system
fell apart just before reaching the coast with the final shipping
warning placing the center about 100 nm east-southeast of Cairns at
0600 UTC on 16 Mar. Gales did occur in the southern semicircle
in the strong easterlies. A ship near 18.6S, 149.6E reported winds
to 35 kts at 16/0000 UTC. Willis Island (WMO 94299) reported winds
to gale force from 2000 to 2130 UTC on the 15th. A QuikScat pass
at 16/0851 UTC showed winds in the easterlies to 45 kts near the
coast south of 17S. On the mainland the Lucinda AWS (WMO 94295)
reported winds of 34 kts at 16/1316 UTC and Cardwell (WMO 94292)
recorded 35-kt winds at 16/2000 UTC. This LOW basically remained
as a trough in the easterlies with no significant westerly flow to
the north. It did bring some heavy rainfall amounts to Queensland
with 24-hour totals of 300 mm falling in the coastal region and
inland ranges near Townsville. The heavy rainfall led to one of the
highest floods on record at Giru (about 40 km south of Townsville).
(All of the winds given above are 10-min mean values. A special
thanks to Jeff Callaghan and Matthew Saxby for sending me observational
data on this system.)
During the last week of March another low-pressure system was the
subject of gale warnings from the Brisbane TCWC. This LOW formed at
higher latitudes and was not a tropical LOW--more of a hybrid system.
The first warning at 24/0500 UTC located the LOW about 265 nm north-
east of Brisbane. The system drifted southward, then north-
northwestward with the final shipping warning at 26/0600 UTC placing
the center about 340 nm east-southeast of Rockhampton. This LOW
displayed very little in the way of convective clouds and brought
almost no rain; however, a few reporting stations did report gale-
force winds on 25 and 26 March.
Tropical Cyclone Steve (TC-14P)
25 February - 12 March
--------------------------------
Tropical Cyclone Steve, although not particularly devastating,
was nonetheless one of the more remarkable Australian tropical
cyclones on record. It came about as close to circumnavigating
the continent as any cyclone has ever done. The parent LOW formed
in the Coral Sea on 25 Feb, was named as Tropical Cyclone Steve by
the Brisbane TCWC on 26 Feb, made a direct hit on Cairns, Queensland,
on 27 Feb, weakened over land, moved over the Gulf of Carpentaria
where it regained cyclone intensity on 29 Feb, and made a second
landfall near Bing Bong, Northern Territory, on 1 Mar. The cyclone
weakened back to a tropical LOW as it moved westward across the
southern "Top End" of the Northern Territory. (For a detailed
description of Steve's strike on Cairns and its history in the Gulf
of Carpentaria, please refer to the February summary.)
At 2230 UTC on 1 Mar the LOW was located about 100 km east of
Katherine, moving west-northwestward at 15 km/hr. CP was reported
at 996 mb with peak wind gusts near the centre of 30 kts. By 0730 UTC
on 2 Mar the system had moved to a position about 40 km south-southwest
of Katherine or about 300 km south-southeast of Darwin, moving to the
west at 15 km/hr. JTWC re-initiated warnings on the system at 1800
UTC on 2 Mar while the center was still inland, estimating the 1-min
MSW at 25 kts. The LOW had moved westward to near the head of the
Joseph Bonaparte Gulf by around 0000 UTC on 3 Mar. At 0130 UTC the
center was relocated (by Darwin) to a point over or very near the
southern extremity of the Gulf about 145 km east-northeast of Wyndham.
At this point the system turned to a west-southwesterly track which
kept the center over land for another 36 hours or so.
Warning responsibility was handed over to the Perth TCWC at around
1000 UTC on 3 Mar. A JTWC warning for 04/1800 UTC noted that the
center of the LOW was nearing the coast and that the Broome radar
indicated the heaviest convection was confined to the periphery of
the system. Moderate to heavy precipitation extended from Pender Bay
southeast to Derby and then southwest across Dampier Land to the coast
near Broome. By 0400 UTC on 5 Mar the center had emerged into the
Timor Sea and was showing signs of regeneration. Perth reclassified
the system as Tropical Cyclone Steve in a shipping warning issued at
the same time. The CP was reported as 988 mb and the maximum 10-min
avg winds estimated at 45 kts. Steve was the first system to become
a named cyclone by each of the three Australian TCWCs. At 1500 UTC
Steve was centered about 80 nm east-northeast of Port Hedland, tracking
west-southwestward at 9 kts with JTWC estimating the 1-min MSW at
55 kts--comparable to Perth's 10-min value of 45 kts. Animated
infrared imagery showed that deep convection was continuing to organise
and wrap around the LLCC with outflow over the system improving. An
upper-level anticyclone was beginning to develop over Steve and
vertical wind shear was low.
Steve continued moving slowly west-southwestward near the Pilbara
coast which hindered development. The cyclone reached Category 2
on the Australian Cyclone Severity Scale at 05/1900 UTC when located
about 55 nm north of Port Hedland or 125 nm northeast of Karratha.
The CP was down to 980 mb and maximum wind gusts were estimated at
65 kts. The storm continued to deepen and reached its lowest CP
of 975 mb at 05/2200 UTC. This pressure was maintained for about
24 hours as the cyclone moved slowly west-southwestward just off the
coast, being located about 20 nm north-northwest of Karratha at
06/0700 UTC. Steve remained stationary in this location until about
1100 UTC when it resumed its west-southwestward movement. The JTWC
warning at 0600 UTC on 6 Mar noted that multi-spectral satellite
imagery showed that the cyclone had continued to strengthen and had
developed a 105-nm diameter CDO. Animated radar imagery from Port
Hedland revealed that the strongest convection was from the south
through the northwest side of the storm. Perth's maximum 10-min avg
winds reached 60 kts at 0400 UTC--this was the peak for the cyclone's
history--and JTWC briefly estimated the 1-min MSW at 65 kts at 1200
UTC before lowering it to 55 kts six hours later.
Tropical Cyclone Steve crossed the Western Australian coast around
1800 UTC on 6 Mar about 75 nm (135 km) west-southwest of Karratha with
sustained winds near 55 kts. Peak gusts were estimated near 80 kts--a
Category 2 cyclone. According to a JTWC warning the LLCC was embedded
about 45 nm into the convection with animated radar imagery from Port
Hedland depicting an inner core of convection straddling the coast near
Dampier with the majority of the convection over water. Steve weakened
as it crossed over the northwestern corner of Western Australia,
passing about 15 nm southeast of Onslow around 06/2200 UTC. The storm
remained intact while over land and actually began to show some signs
of re-intensification before emerging into the Indian Ocean around
1400 UTC on 7 Mar about 80 nm (145 km) south-southwest of Exmouth or
about 105 nm (190 km) north of Carnarvon, moving slowly to the west-
southwest at 5 kts.
Steve's intensity held steady at 45 kts (per Perth's shipping
warnings) from 07/0400 UTC through 08/1600 UTC before beginning to
slowly weaken once more. JTWC increased their MSW estimate to 55 kts
for about 12 hours on 7 Mar but decreased it to 50 kts at 0600 UTC
on the 8th. The JTWC warning issued at that time indicated that
some of the convection was beginning to shear off to the east and that
animated radar imagery from Dampier showed that the LLCC was near the
tip of Cape Ronsard in the Geographe Channel. Animated water vapour
imagery continued to show good outflow aloft. The cyclone did not
advance very far into the Southeast Indian Ocean before it stalled and
slowly recurved to the east-southeast in advance of a shortwave trough
associated with a frontal system approaching southwestern Australia.
At 08/1200 UTC JTWC noted that convection had begun to weaken and
become more disorganised. Animated radar imagery from Carnarvon at
this time showed that the LLCC was situated over the northern end of
Bernier Island.
Perth cancelled the cyclone warnings and issued the last shipping
warning at 09/0400 UTC with Steve's center located about 45 nm south
of Carnarvon and 25 nm northeast of Denham. The weakening cyclone was
expected to cross the coast in Shark Bay during the afternoon. JTWC,
however, continued to issue warnings, increasing the MSW briefly to
50 kts at 1200 UTC. This was based upon current satellite intensity
estimates of 35 kts and 45 kts. Animated infrared imagery showed that
the convection had strengthened slightly over the previous six hours
and that a large, symmetrical area of convection 90 nm in diameter
was centered over the LLCC. The storm made landfall near Hamelin
around 1300 UTC. By this time most of the convection was overland
east and south of the LLCC.
Following landfall the weakening Steve continued southeastward
across Western Australia with convection remaining persistent near
the LLCC for several hours, but eventually westerly wind shear
increased and the system began to weaken rapidly. The remnant LOW
eventually moved out into the Great Australian Bight where it
produced gales along the coasts of Western Australia and South
Australia as an extratropical LOW before speeding off to the southeast.
It is also possible that some gales were experienced along the
southwestern coasts of Victoria and Tasmania which, if true, would
mean that every Australian state except New South Wales, plus the
Northern Territory, would have experienced gale-force winds with this
cyclone--hence the statement that Steve virtually circumnavigated the
continent. Steve is also the first known Australian cyclone to make
four distinct landfalls in the country.
The author has received no reports of damage connected with Steve's
two landfalls in Western Australia. But while Steve was crossing
the Northern Territory storm-force wind gusts occurred across the Top
End as the system maintained a strong mid-level circulation while it
moved inland. Oenpelli reported heavy rainfall with severe wind
squalls (recorded near 50 kts) around 2030 UTC on 1 Mar, causing trees
to be uprooted around the town. Also, on 2 Mar Bing Bong port (where
Steve had made landfall) reported winds as strong as those experienced
the previous day during the cyclone's landfall, and tides ran 1.5 m
higher than expected. Gales were observed through the Timor Sea
between 2 and 3 Mar, and storm-force gusts during the night of 2-3 Mar
in the Darwin area brought trees down.
As the tropical LOW moved across the base of the Top End widespread
flooding resulted in the Katherine, Daly and Victoria River regions.
Though rainfall amounts were not large, the catchments were already
saturated. Active monsoonal conditions across northern Australia
during February resulted in rainfall across the Top End and Kimberley
regions being much higher than average. Rainfall across the Victoria
River region from 9am (CST) on 29 Feb to 9am (CST) on 4 Mar was
between 200 and 400 mm. Similar totals were recorded in the Kimberley
region over the four days ending on 5 Mar. Many roads were cut by
the floodwaters and many communities had to be evacuated. Water levels
in the Katherine River came to within about 3 m of those experienced
in the 1998 floods but fortunately subsided without inundating the
town.
Severe Tropical Cyclone Norman (TC-16S)
28 February - 8 March
----------------------------------------
At 0100 UTC on 28 Feb BoM Perth issued a Tropical Cyclone Advice for
a tropical LOW which was located inland over the Kimberley region of
Western Australia. The LOW was centered about 285 km south of
Kalumburu or about 475 km east of Derby. The LOW was forecast to move
off the coast into the Timor Sea within the next 36 hours and possibly
develop into a tropical cyclone. The LOW continued to track to
the west and moved offshore on 29 Feb and began to show signs of
intensifying. JTWC issued a Formation Alert at 29/1600 UTC, estimating
winds in the system to be around 25-30 kts. Synoptic data indicated
the existence of a well-defined LLCC and microwave imagery revealed
an increase in the organization of deep convection. The center of
the LOW was located about 200 nm west of Broome at this time.
Perth named the LOW Tropical Cyclone Norman at 0100 UTC on 1 Mar
with 45-kt winds and centered about 125 nm north-northwest of Port
Hedland. (The first warning by JTWC was issued at 0600 UTC.) By
1800 UTC Norman had intensified significantly and both Perth and JTWC
were estimating the maximum winds at 55 kts. Cloud tops near the
center were -85 C and a well-defined CDO had formed. The cyclone
continued to strengthen and Norman had reached hurricane intensity
by 0400 UTC on 2 Mar with Perth assigning a maximum 10-min avg wind
estimate of 70 kts. Water vapour imagery indicated good outflow and
a SSM/I pass at 02/0112 UTC suggested the presence of a ragged
eyewall. Norman's center was located about 200 nm north-northwest
of Exmouth at this time and still moving westward away from the Western
Australian coastline. By 02/1800 UTC the storm had begun to move
west-southwestward at 14 kts and was still intensifying with excellent
outflow and a 10-nm diameter eye. Perth's and JTWC's respective
MSW estimates had increased to 75 kts (10-min) and 95 kts (1-min).
Severe Tropical Cyclone Norman continued to rapidly intensify and
reached its peak intensity around 0400 UTC on 3 Mar. Perth estimated
the maximum 10-min avg wind at 110 kts with an attendant CP of 920 mb,
and JTWC's peak MSW was 120 kts (based on satellite intensity estimates
of 115 and 130 kts). At its peak Norman sported a 25-nm diameter eye
with the radius of 100 kt winds (1-min MSW) estimated at 30 nm.
Winds to 50 kts extended out 110 nm to the south of the center and
75 nm elsewhere while gale-force winds covered a zone almost 350 nm
across. Norman's center was located about 425 nm west-northwest of
Exmouth at the time of peak intensity, moving westward at 14 kts.
By later in the day the winds had dropped slightly and the cyclone
had increased its forward motion to 18 kts. The eye measured 20 nm
in diameter and was still cloud-free.
Over the next few days Norman continued moving on a rather straight
westerly course as it gradually weakened. By 4 Mar 200-mb analysis
showed that the tropical cyclone was north of the subtropical ridge
axis and under some east-northeasterly flow aloft. CIMSS charts
indicated that Norman was under some weak vertical shear. By 1600 UTC
the center had become partly-exposed with associated convection
displaced 20 nm to the west-southwest of the LLCC. Perth's intensity
estimate had dropped to 75 kts while JTWC's MSW was down to 90 kts.
By 0400 UTC on 5 Mar Norman's winds had dropped further, and JTWC had
decreased their MSW estimate to minimal hurricane force (65 kts) while
Perth's 10-min avg value was down to 60 kts. A TRMM pass at 05/1663
UTC showed a relatively symmetric system with two banding features
positioned to the east and northwest of the center. Norman's former
rapid westward forward motion also had slowed down considerably as
the cyclone drifted slowly westward within a weakness in the
subtropical ridge.
Around 2200 UTC on 5 Mar Norman became quasi-stationary for several
hours approximately 575 nm southwest of Cocos Island, after which time
it turned rather abruptly to a slow southerly track. Early on 6 Mar
(0315 UTC) a SSM/I pass depicted a 70-nm diameter ring of deep
convection with the LLCC centered within the ring. Animated multi-
spectral imagery revealed a banding eye with excellent outflow.
Norman held on to its intensity through the 6th but began to weaken
slowly on the 7th and then rapidly on 8 Mar. Animated satellite
imagery on 7 Mar revealed a spiral band of convection elongating to
the southeast as a result of increased vertical shear in association
with a mid-latitude system passing to the south of the cyclone.
Infrared imagery indicated rapidly warming cloud tops.
The weakening cyclone drifted somewhat to the southeast on 7 Mar
but moved back northward on the 8th. Perth wrote its last warning
at 08/0400 UTC when the center was located about 750 nm south-
southwest of Cocos Island. By 0600 UTC the LLCC was completely
exposed with the convection sheared to the southeast. JTWC assigned
a MSW of 45 kts based on widely divergent satellite intensity estimates
ranging from 30 to 65 kts. JTWC issued its final warning at 08/1800
UTC with winds estimated at only 25 kts. The system was devoid of any
deep convection with only a weak convective band displaced about 150 nm
to the southeast of the LLCC. (At one point it was anticipated that
Norman would move across 90E into the Southwest Indian basin. MFR
issued a few bulletins on the storm, numbering it as system #11.)
Tropical Cyclone Olga (TC-20S)
15 - 21 March
-------------------------------
On Mar 14 an area of convection had developed about 170 nm south-
west of Darwin in the region of the Joseph Bonaparte Gulf. Infrared
and visible imagery depicted persistent convection and synoptic data
indicated a weak LLCC. CIMSS analysis showed generally favorable
conditions for development under an upper-level ridge axis. By
1800 UTC the original LOW had weakened and a new one had formed much
farther west--about 120 nm west of Yampi Sound. BoM Perth issued
the first marine warning at 0000 UTC on 15 Mar when the LOW's center
was located 200 nm north of Port Hedland. The system was displaying
improved organization with low-level cloud lines clearly visible to
the south of the LLCC. JTWC issued a Formation Alert at 0800 UTC
and the first warning at 1200 UTC, designating the LOW as TC-20S.
The system was then centered about 250 nm northwest of Port Hedland
and moving westward at 13 kts within a mid-level ridge over Western
Australia. At 16/1200 UTC JTWC relocated the center about 100 nm
east of their previous 12-hour forecast position. Animated visible
imagery indicated multiple LLCCs near the convection. TC-20S at
this time was a broad-scale circulation with the convection sheared
to the west and south of the center.
BoM Perth upgraded the LOW to Tropical Cyclone Olga at 0400 UTC
on 17 Mar when it was centered about 300 nm north-northwest of
Exmouth, Western Australia. Peak 10-min avg winds were estimated at
45 kts. (JTWC's 1-min MSW was still reported as 30 kts.) Olga
moved slowly on a generally southwestward track off the Western
Australian coastline after being upgraded to a cyclone. Satellite
imagery indicated a partially-exposed LLCC east of the deep convection
with an anticyclone to the east and an upper-level trough to the
south enhancing the upper-level winds. At 1200 UTC JTWC increased
their MSW estimate to 35 kts; however, a SSM/I pass at 17/1032 UTC
indicated a fully-exposed LLCC.
By 0000 UTC on 18 Mar Olga had tracked into a slightly more
favorable environment underneath the subtropical ridge axis. The LLCC
was located on the eastern edge of the deeper convection and outflow
had improved. JTWC estimated the 1-min MSW at 45 kts, but Perth's
peak 10-min avg wind was even higher at 55 kts. At 17/2200 UTC the
center of the cyclone was about 325 nm northwest of Exmouth, still
moving slowly southwestward. A TRMM pass at 18/0904 UTC depicted a
fully-exposed LLCC with convection displaced 70 nm west of the LLCC;
however, the two warning centers maintained their previously estimated
respective MSW's through 1200 UTC on the 18th. Thereafter, the
winds began to diminish as shear generated by the upper-level ridge
to the south increased.
Early on 19 Mar convection intensified and increased in areal
extent for a few hours, but this attempt at re-intensification did not
persist. JTWC issued its final warning at 0600 UTC with the LLCC still
fully-exposed and a stratocumulus deck replacing the isolated
convection over the southern periphery. Perth downgraded Olga back
to a tropical LOW at 2200 UTC but continued to issue warnings over the
next couple of days for gales in the southern quadrants due to a
developing high-pressure area to the south. The remnants of Olga
drifted slowly southwestward through around 0000 UTC on 20 Mar and
then turned more to the west. The final Perth bulletin on the system
at 21/0700 UTC placed the weakening center about 700 nm west of
Carnarvon.
***********************************************************************
SOUTHWEST PACIFIC (SWP) - South Pacific Ocean East of Longitude 160E
Activity for March: 1 tropical depression **
1 tropical cyclone of storm intensity
1 tropical cyclone of hurricane intensity
** - System moved into Australian Region in early April and developed
into Tropical Cyclone Vaughan.
Most of the information presented below was taken from the
operational warnings and advisories issued by the Fiji TCWC at Nadi.
References to sustained winds imply a 10-minute averaging period
unless otherwise noted. Also, the basic definition of a cyclone in
WMO Region 5 (Australia and the South Pacific) has the unique
requirement that a depression must have gale-force winds more-or-less
completely surrounding the center before the system is named as a
tropical cyclone. Hence, often gales of 35-40 kts may be present in
one or two quadrants but the system is not considered a tropical
cyclone. Last season Fiji initiated their own numbering scheme for
tropical disturbances (01F, 02F, etc) that form in the Nadi AOR.
Some of the numbered disturbances never warrant depression status.
The reports on Tropical Cyclones Leo and Mona were written by
Alipate Waqaicelua, Chief Forecaster at the Nadi TCWC, with only
minimal editing by myself. A very special thanks to Alipate for
sending me the summaries and the cyclone tracks. Also, a special
thanks to Steve Ready of the New Zealand Meteorological Service
for sending me some damage reports and synoptic observations
regarding Leo and Mona.
Southwest Pacific Activity for March
------------------------------------
As was the case with February, tropical cyclone development in the
South Pacific was confined to the area east of the 180th meridian.
Leo formed on the 6th from a TUTT-initiated disturbance and was named
as a tropical cyclone just before leaving Nadi's AOR. The cyclone
reached storm intensity as it sped southward and southeastward through
Wellington's AOR. Mona began forming at about the same time near
Samoa and eventually reached hurricane force after having moved through
some of the islands in the Kingdom of Tonga, causing moderate damage.
From around 9-12 Mar a system northwest of Vanuatu was designated
as Tropical Disturbance 16F. This LOW developed in a monsoon trough
with good westerlies to the north and an easterly surge to the south
from a HIGH in the Tasman Sea. The disturbance was in an area under
good diffluence and low vertical shear, but convection was not able
to become well-organized and the system was never referred to as a
tropical depression. No track is given for this system in the
accompanying tracks file. Another disturbance late in the month
formed in the same general area, tracked to the south, and became
a tropical depression (17F). The depression eventually moved westward
into the Australian Region on 2 Apr where it developed into Tropical
Cyclone Vaughan on 3 Apr. (This system will be covered in its
entirety in the April summary.)
Tropical Cyclone Leo (TC-18P / TC-14F)
5 - 9 March
---------------------------------------
Tropical Depression 14F was first identified by RSMC Nadi as a
tropical disturbance around 04/0600 UTC, almost stationary, and located
about 60 nm west-northwest of French Polynesia under a TUTT. In the
next 24 hours the disturbance had developed into a tropical depression,
drifting slowly southwwestward, but remaining just north of an upper-
level anticyclone in a diffluent region of relatively weak to moderate
shear. Convection had also increased with weak indications of spiral
bands forming. SSTs were around 28-29 C and the potential at that
point for development into a tropical cyclone within the next 48 hours
was moderate and anticipated to increase further. At 05/0000 UTC the
first gale warning was issued for the depression warning of gales
within certain sectors of the system. The depression was centered
about 300 nm west-southwest of Tahiti at the time.
Overnight on the 5th the system continued to develop and moved
farther southwest through the Southern Cooks, which registered
significant 24-hour pressure falls. After 06/0000 UTC the system
underwent some weakening under increasing shear. The depression was
then moving under an upper-level (250 mb) shortwave trough. Cold
convective tops also warmed and overall organisation decreased.
However, after 06/0600 UTC the system, now located about 100 nm south-
southwest of Rarotonga in the Southern Cooks, re-intensified with
spiral bands wrapping tightly around the LLCC. Convection increased
considerably over the LLCC with tops cooling. Overall organisation
went through a very remarkable change--development was almost
explosive.
TD-14F was named Tropical Cyclone Leo at 1200 UTC on 6 Mar when it
was centered about 325 nm west-southwest of Mangaia in the Southern
Cooks. The cyclone accelerated south-southwestward away from the
Cook Islands and continued to intensify as it crossed the 25th parallel
and entered Wellington's AOR. Leo reached a peak intensity of 50 kts
at 07/0000 UTC and maintained its strength for about 24 hrs. After
1800 UTC the storm began to recurve to the southeast and by 0000 UTC
on the 8th was becoming extratropical as it came under strong shear
and encountered much cooler SSTs.
While still a tropical depression Leo passed over the small island
of Mangaia (southwest of Rarotonga) between 1200 and 1800 UTC on
5 Mar. No damage reports have been received and it is likely that
any damage incurred on Mangaia would have been very minor. (This
information from Steve Ready of the New Zealand Meteorological
Service.)
Tropical Cyclone Mona (TC-19P / TC-15F)
7 - 13 March
----------------------------------------
Close to the same time that Leo (14F) was named, around 06/0900 UTC,
another tropical disturbance was identified by RSMC Nadi, located about
70 nm south of Apia, Western Samoa, along the SPCZ and moving slowly
southwestward. At this time the system was lying under the 250-mb
outflow centre with good diffluence over it. Convection was also
increasing and organisation improving, especially during the preceding
12 hours. By 07/0600 UTC the disturbance had developed further into a
tropical depression, prompting the first Gale Warning, though in
certain sectors only, within 90 nm of the centre. The depression was
then located about 120 nm southeast of Niuatoputapu in Northern Tonga
and moving southward at about 5 kts.
At 07/1800 UTC the depression was located near Vavau, in Central
Tonga, and moving southwestward but clearly well-organised, as seen in
visible imagery. The first Special Weather Bulletin (SWB) for Tonga
was then issued (subsequent bulletins were issued every three hours),
warning of damaging gales or stronger winds during the next 24 hours,
especially for Vavau, Haapai, and Tongatapu groups and nearby smaller
islands. Though the depression was generally developing, diurnal
effects together with some shear were still evident, as after 08/0000
UTC, deep convective tops had warmed somewhat and the LLCC became
displaced a little to the west. However, after 08/0600 UTC convection,
especially near the centre, erupted and outflow in all quadrants was
well-developed. The LLCC had also moved under the deep convection,
which had significantly increased spatially. Hence, at 08/1200 UTC,
TD-15F was named Tropical Cyclone Mona with winds of 35 to 40 kts and
located about 40 nm west of Haapai or about 70 nm north of Tongatapu.
The cyclone remained slow-moving but was expected to gradually move
southward under a northerly to northwesterly steering field.
The whole Tongatapu Group was put on Storm Warning in the 7th SWB
for Tonga which was issued around 08/1500 UTC, and mentioned winds
increasing to destructive storm force in the next 12 to 18 hours. In
the same bulletin Vavau and Haapai groups were still under Gale
Warning. Vavau was cleared from the Gale Warning at 08/2100 UTC.
Mona attained storm intensity (>47 kts) by 08/1800 UTC while located
about 110 nm west-southwest of Haapai or 30 nm northwest of Tongatapu
and moving south-southwestward at 5 kts. Indications of an eye
appeared at 09/0000 UTC, suggesting further intensification and
possibly attainment of hurricane intensity. The International Marine
Warning was upgraded to hurricane intensity at 09/0600 UTC with the
persistence of the eye, which was cloud-filled. At this time the
cyclone was located about 30 nm west of Tongatapu and moving south-
southeastward at about 5 kts under a mean deep northerly current. At
09/1200 UTC the Gale Warning for Haapai was cancelled and the Storm
Warning for Tongatapu downgraded to a Gale Warning. The final Gale
Warning for Tongatapu was issued at 09/1800 UTC as Mona turned further
away from the Kingdom.
The cyclone continued south-southeastward, gaining speed as it
headed towards Wellington's AOR. This slight acceleration together
with diffluence created by the retrogressive upper-level trough
augmented the intensity to 70 kts by 0600 UTC on 10 Mar when Mona's
centre was located about 200 nm southeast of Tongatapu. (NPMOC's
peak 1-min MSW estimate at this time was 80 kts which represents
excellent agreement with Nadi.) The lowest CP estimate in Mona's
history, also at 10/0600 UTC, was 965 mb. Warning responsibility
was handed over to Wellington at 1200 UTC with the cyclone still at
its peak intensity of 70 kts. However, Mona began to weaken rather
rapidly as it sped off to the south and had become extratropical by
1200 UTC on 11 Mar. The remnant extratropical LOW still produced gales
for another couple of days as it moved southward and then rapidly east-
southeastward as it got caught up in the westerlies.
Damage, especially in Vavau and Haapai groups, was mainly to crops,
primarily to banana, breadfruit and coconut plantations. In Tongatapu
moderate damage was sustained by houses (mainly those of poorer
construction) and by some school buildings. The unofficial damage
assessment, according to the Tongan National Disaster Management
Office, totalled Tongan $6 million. Of this amount T$4.7 million was
to agriculture alone. A police patrol boat sank off Eua Island in
the Tongatapu group. Surge/swell also affected Tongatapu. Coconut
plantations are still recovering from Tropical Cyclone Cora which
affected them in December, 1998.
Strongest winds/lowest pressures experienced are given below:
Vavau:
07/1900 UTC, 10-min winds 34 kts/Gust 54 kts, Pressure 999 mb
Haapai:
08/1100 UTC, 10-min winds 30 kts/Gust 45 kts, Pressure 1003 mb
Fua'motu Airport (Tongatapu):
08/1500 & 09/1500 UTC, 10-min winds 50 kts/Gust 75 kts, Pressure 999 mb
Nuku'alofa (Capital of Tonga, on Tongatapu):
08/1500 & 09/1500 UTC, 10-min winds 44 kts/Gust 65 kts, Pressure 998 mb
One can see that the wind/pressure relationship typical of "normal"
cyclones is clearly not valid with Mona. This does suggest the
existence of strong gradients outward, which would then qualify Mona
as a small (or even midget) cyclone.
***********************************************************************
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 included in the July, 1998 summary.
I will include this glossary from time to time, primarily in "lean"
months without a lot of tropical cyclone activity to cover. But if
anyone missed receiving it and wishes to obtain a copy, send me an
e-mail privately and I'll forward 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
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) Go to "data" subdirectory (Type: cd data)
(e) Set file type to ASCII (Type: ascii)
(f) Transfer file (Type: get remote_file_name local_file_name )
(The files will be named with an obvious nomenclature--using
March as an example: mar00.tracks)
(g) To exit FTP, type: quit
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. If anyone wishes to retrieve any of the previous summaries,
they may be downloaded from the aforementioned FTP site at HRD. The
summary files are catalogued with the nomenclature: mar00.sum, for
example.
Back issues can also be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Tom Berg, Michael
Pitt, and Rich Henning):
http://australiansevereweather.com/cyclones/>
http://www.geocities.com/capecanaveral/6825>
http://www.hcane.com/tropcl.html>
http://www.qisfl.net/home/hurricanemike>
http://www.met.fsu.edu/gsc/Docs/Grads/henning/cyclones/>
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
I have discovered that JTWC now has available on its new website
the complete Annual Tropical Cyclone Report (ATCR) for 1998 (1997-1998
season for the Southern Hemisphere). Also, ATCRs for earlier years
are available also.
The URL is: http://199.10.200.33/jtwc.html>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 1999 Atlantic and Eastern North Pacific
tropical cyclones; also, preliminary storm reports for all the 1999
Atlantic and Eastern North Pacific cyclones are now available.
The URL is: http://www.nhc.noaa.gov>
Prepared by: Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327 (nights & weekends) / 850-882-2594 (weekdays)
***********************************************************************
***********************************************************************
|
Document: summ0003.htm
Updated: 4th January 2007 |
[Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] |