Tropical Cyclones
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Monthly Global Tropical Cyclone Summary April 2000
[Summaries and Track Data] [Prepared by Gary Padgett]


                               APRIL, 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.)


                     TROPICAL CYCLONE NAMES FOR 2000

           ATLANTIC                      EASTERN               CENTRAL
                                      NORTH PACIFIC         NORTH PACIFIC

    Alberto        Leslie         Aletta *       Miriam         Upana
    Beryl          Michael        Bud *          Norman         Wene
    Chris          Nadine         Carlotta       Olivia         Alika
    Debby          Oscar          Daniel         Paul           Ele
    Ernesto        Patty          Emilia         Rosa           Huko
    Florence       Rafael         Fabio          Sergio         Ioke
    Gordon         Sandy          Gilma          Tara           Kika
    Helene         Tony           Hector         Vicente        Lana
    Isaac          Valerie        Ileana         Willa
    Joyce          William        John           Xavier
    Keith                         Kristy         Yolanda
                                  Lane           Zeke

    * = name has already been assigned to a tropical cyclone

                            APRIL HIGHLIGHTS

  --> Tropical Cyclone Hudah strikes Madagascar and Mozambique
  --> Severe Tropical Cyclone Rosita strikes Western Australia
  --> Two small midget cyclones form in Coral Sea--one hits Queensland

                           ACTIVITY BY BASINS

  ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico

  Activity for April:  No tropical cyclones


  NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180

  Activity for April:  No tropical cyclones


  NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180

  Activity for April:  No tropical cyclones

  NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea

  Activity for April:  No tropical cyclones


  SOUTH INDIAN OCEAN (SIO) - South Indian Ocean West of Longitude 90E

  Activity for April:  1 moderate tropical storm
                       1 subtropical cyclone (of at least gale force)
                       1 intense tropical cyclone (from March)

     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

     Much of the material presented on the so-called "subtropical
  cyclone" in mid-April was taken from information sent to me by Roger
  Edson of the University of Guam.  A special thanks to Roger for sending
  me the write-up on this very interesting system.

                   South Indian Ocean Activity for April

     Intense Tropical Cyclone Hudah, which had formed in March, was the
  major tropical cyclone item in the Southwest Indian basin during April.
  As the month opened the intense storm was still gathering strength
  about 200 nm northeast of Mauritius and made a destructive strike on
  northern Madagascar on the 2nd.  After weakening to below tropical
  cyclone (hurricane) intensity, Hudah made a comeback in the Mozambique
  Channel and made a second landfall in northern Mozambique.   Around
  mid-month minor Tropical Storm Innocente stirred the waters of the
  central South Indian Ocean for a few days.  Also, during the second
  week of April a system developed in the Mozambique Channel and
  flirted with the coasts of Mozambique and later Madagascar.  This
  system was classified as a subtropical cyclone by La Reunion and as a
  hybrid, subtropical system by JTWC.  However, Roger Edson and Mark
  Lander of the University of Guam feel that the system was primarily
  a tropical cyclone at its peak.   Roger has supplied an alternate
  track for the disturbance which is included below along with the
  track based upon MFR's warnings.

                Tropical Cyclone Hudah  (TC-21S / SIO #12)
                            24 March - 9 April

     To repeat the opening paragraph of the discussion of Hudah from
  the March summary:

     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.

     Hudah had formed in late March in the western portion of the
  Australian Region and had reached tropical storm intensity just before
  crossing longitude 90E into the Southwest Indian basin where it was
  promptly named Tropical Storm Hudah by the Mauritius Meteorological
  Service.  For a detailed discussion of the first week of Hudah's life,
  please refer to the March tropical cyclone summary.   At 0000 UTC on
  1 Apr Hudah was an intense cyclone located about 225 nm northeast of
  Mauritius, moving on a westerly track toward a disastrous rendezvous
  with Madagascar.   La Reunion's (MFR) 10-min avg wind estimate was
  100 kts and was increased to 110 kts by 0600 UTC.  Dvorak ratings were
  a solid T=6.5 and JTWC increased their 1-min MSW estimate to 125 kts
  at 1200 UTC.  At 1200 UTC the eye of Hudah was 400 nm east of
  Antanambe, Madagascar, and moving west-northwestward at 13 kts.

     The cyclone reached its peak intensity of 905 mb and 120 kts peak
  10-min wind (per MFR's analysis) at 02/0600 UTC.   JTWC never assigned
  a 1-min MSW greater than 125 kts, but the 120 kts 10-min avg would
  equate to a 1-min MSW of 135 kts.  Hudah was still a small cyclone
  with 50-kt winds only occurring within about 25 nm of the center.  A
  SSM/I pass depicted a 20-nm wide eye with a concentric eyewall feature.
  By 1200 UTC the center was closing in on the coast of Madagascar, being
  located only about 85 nm east-southeast of Antalaha.     The eye of
  intense Tropical Cyclone Hudah made landfall around 1730 UTC on 2 Apr
  about 15 nm southeast of Antalaha with winds in the neighborhood of
  115-120 kts, gusting much higher.   The eye had moved off the northwest
  coast of Madagascar by 03/1200 UTC and was located about 35 nm north
  of Majunga.  The majority of the convection was south of the center,
  wrapping into the west quadrant.  JTWC was estimating the intensity
  at 70 kts, but MFR had dropped their estimate to 40 kts.  However, in
  the next JTWC warning at 04/0000 UTC the MSW was reported as 45 kts.

     Hudah continued to move westward farther out into the Mozambique
  Channel and slowly began to regain intensity as deep convection began
  to rebuild around the LLCC.  By 04/1200 UTC winds had picked up to
  50 kts (55-kt MSW from JTWC) and the storm was centered about 105 nm
  east-southeast of Nacala, Mozambique, moving westward at 11 kts.
  Hudah's forward motion slowed considerably as it neared the coast of
  Mozambique.  At 05/1200 UTC the center was only about 25 nm east of
  Porto de Moma and moving to the west at only 6 kts.   JTWC increased
  the MSW to 65 kts at 05/0000 UTC and MFR re-upgraded Hudah to tropical
  cyclone (hurricane) intensity 24 hours later.

     Upper-level diffluence over the cyclone improved on 6 Apr and winds
  climbed back up to 80 kts (90 kts MSW from JTWC).   The storm's motion
  became slow and erratic on the 6th as it drifted generally toward the
  south.   At 1800 UTC Hudah was centered about 120 nm southeast of
  Quelimane and appeared to be tracking south-southeastward at 4 kts.
  The cyclone was caught in a weakness in the subtropical ridge created
  by a mid-latitude trough just off the coast of South Africa.   A
  significant banding feature had developed over the western half of the
  system and a 06/1807 UTC SSM/I pass indicated an irregular eye 15 nm
  in diameter.   By 0000 UTC on 7 Apr Hudah was centered about 200 nm
  east of Beira and was drifting to the west-southwest at 2 kts.  The
  mid-latitude trough had decreased in amplitude considerably over the
  preceding 12 hours and the subtropical ridge was forecast to build
  back over the Channel.   At 0600 UTC MFR increased the peak 10-min avg
  winds to 85 kts with JTWC upping their MSW estimate to 100 kts.  By
  this time Hudah had begun to drift very slowly to the north-northwest.
  By later on the 7th Hudah was drifting northward with the trough
  having tracked eastward and the cyclone coming under the influence
  of a HIGH over Africa.

     Hudah's pace to the north picked up a bit on 8 Apr as the storm
  began to weaken slightly.  At 0000 UTC the cyclone was centered about
  85 nm east of Quelimane with the intensity having dropped to 80 kts
  (10-min avg) and 95 kts (1-min MSW).   Animated infrared imagery
  showed that the eye had become ragged and cloud-filled.   Tropical
  Cyclone Hudah made landfall around 0600 UTC near Pebane, Mozambique,
  tracking northward at 8 kts.  The storm began to weaken rapidly after
  making landfall with MFR writing their final warning at 1800 UTC on
  the 8th.   JTWC issued their final warning at 0600 UTC on 9 Apr, the
  system having essentially dissipated, although orographic effects
  of the mountains apparently were responsible for some localized,
  persistent convection as the remnants drifted northward over north-
  eastern Mozambique.

     Philippe Caroff and Patrick Hoareau have sent me some observations
  made on various islands as Hudah passed by.  On 31 Mar Hudah's center
  passed about 30 nm south of St. Brandon.  A maximum 10-min avg wind
  of 39 kts was recorded with peak gusts to 55 kts.  The northern edge
  of the eyewall was only 15 nm south of the island, implying that the
  extent of storm-force (>47 kts) winds was very limited.  The cyclone
  passed at some distance north of the islands of Rodrigues, Mauritius
  and Reunion where peak gusts did not exceed 45 kts.    The highest
  rainfall totals on Mauritius did not exceed 30 mm.   Shortly before
  reaching peak intensity Hudah passed only about 15 nm south of Tromelin
  where a maximum 10-min avg wind of 68 kts was recorded with the peak
  gust reaching 98 kts.  (Thanks to Philippe and Patrick for passing
  along this information.)

     The city of Antalaha on Madagascar where Hudah made landfall was
  about 90% destroyed.  The death toll was reported at 20 with over
  300,000 persons severely affected by the cyclone.  The storm destroyed
  food storage warehouses, and in Antalaha all wooden homes and buildings
  were destroyed and the roofs ripped off most concrete structures.
  Telephone and electricity lines were downed and schools and churches
  heavily damaged.   This region is one of the world's primary vanilla
  producing areas, and reports indicated Hudah destroyed approximately
  one-half of the vanilla crop.   Media reports stated that Hudah was
  the worst tropical cyclone to affect the Antalaha region in 20 years.

     There was a report from Antalaha of wind gusts to 163 kts.  It is
  unclear whether this was a reliable measured value or an estimate.  If
  verified, it would imply peak 10-min avg winds in the range of 115-120
  kts and a peak MSW of 130-135 kts at landfall.   The effects of Eline,
  Gloria, and Hudah have combined to make the 1999-2000 cyclone season
  the worst for eastern Madagascar since that of 1993-1994 when Tropical
  Cyclones Daisy, Geralda, Litanne, and Nadia all struck the eastern
  coast at full cyclone intensity.

     The author has received no reports of any damage or casualties
  resulting from Hudah's landfall in northern Mozambique.  If any become
  available later they will be reported in a future summary.

                       Subtropical Cyclone  (SIO #13)
                                7 - 17 April

     An extratropical system moved off the coast of South Africa during
  the period 5-7 Apr.   A circulation was evident about 325 nm east-
  northeast of Durban by 0000 UTC on 7 Apr.     Whether or not this
  circulation was directly associated with the African extratropical
  LOW or already existed in the area along an old shear line isn't
  totally clear.     The circulation was indirectly part of the old
  frontal boundary/extratropical system so was basically classifiable
  as a subtropical LOW at this time.   Winds perhaps reached 30 kts on
  7 and 8 Apr but decreased on the 9th.  There was a south to north
  surge in low-level winds in excess of 30 kts west of the circulation,
  so the 30-kt MSW is an attempt to define the winds in the immediate
  vicinity of the LLCC.

     The disturbance initially drifted north-northeastward in the
  Mozambique Channel, then turned to the north, and by 9 Apr was drifting
  north-northwestward toward the Mozambique coast.  By this time the LOW
  was isolated from any extratropical system, and convection, although
  fairly shallow, began to slowly develop near the LLCC.   According to
  Roger Edson's track (see below) the center of the storm just reached
  the coast near Inhambane around 11/1200 UTC with the MSW estimated at
  55 kts.   MFR initiated warnings on the system at the same time,
  calling it a subtropical cyclone with 10-min avg winds of 30 kts.
  (Since it was MFR's 13th numbered disturbance of the season, I shall
  refer to it as STC-13.)         The center seemed to drift north-
  northeastward and moved just offshore over the next 24 hours while
  showing signs of strengthening.  JTWC, while referring to the system
  as a hybrid-type LOW, issued the first of three Formation Alerts at
  12/0130 UTC, and MFR increased the 10-min wind estimate to 35 kts
  at 1200 UTC.  In Roger's opinion the LOW reached hurricane force at
  12/0000 UTC and peaked at 70 kts 1-min MSW at 1200 UTC.   This was
  based upon visible, infrared, and TRMM imagery.   No warnings on
  STC-13 were issued by JTWC but the Formation Alerts indicated that
  maximum winds were likely in the 25-30 kt range.

     Following its flirtation with the Mozambique coast, STC-13 turned
  eastward and began to accelerate slightly as it headed in the direction
  of southern Madagascar.    By 14/0000 UTC the convection was beginning
  to shear off, and MFR decreased the 10-min winds to 30 kts while
  Roger's 1-min MSW estimate was down to 45 kts.    STC-13 was located
  about 250 nm west of Tulear on the southwestern coast of Madagascar
  at this time, and subsequently seemed to brush the southwestern tip
  of the island and then move on off to the southeast.  By 0000 UTC on
  the 15th all the convection was gone and the mid-levels were overrun
  by extratropical cloudiness.   JTWC had issued the third Formation
  Alert at 0130 UTC on 14 Apr but cancelled it at 0530 UTC after it
  became obvious that the convection was shearing off and STC-13 was
  beginning to acquire more extratropical features.   Scatterometer data
  still showed a circulation on 16 and 17 Apr but this wasn't apparent
  in satellite imagery.

     It is obvious that there is disagreement among tropical experts as
  to how to classify this system.   La Reunion and JTWC considered it to
  be a subtropical, hybrid-type system, while Roger Edson and Mark Lander
  feel that it was a "true blood" tropical cyclone.   There is no doubt
  that it became isolated from any extratropical system and that it had
  at times some convection rather tightly wrapped around an eye-like
  feature.    The sticking point seems to be the shallowness of the
  convection, with cloud top temperatures ranging from only around -45 to
  -55 C--considerably warmer than in most conventional tropical cyclones.
  I went back and read some of the TPC/NHC discussions on Tropical Storm
  Nicole in November, 1998, at the time that system was named.  Based
  upon the comments and also upon my memory of Nicole's appearance in
  satellite imagery at the time as compared with STC-13's appearance,
  I think it likely that the two systems were very similar in the degree
  and depth of convection.    In Nicole's case there was a ship report
  of sustained winds to 58 kts about the time that an intermittent
  eye appeared in the small CDO.      This perhaps might suggest that
  STC-13 could have been of a comparable intensity.  (In his comments
  Roger points out that he had no surface observations upon which to
  base his intensity estimates--only infrared imagery, TRMM data, and
  scatterometer data.)

               Tropical Storm Innocente  (TC-26S / SIO #14)
                              12 - 19 April

     Tropical Storm Innocente was a weak, insignificant system which
  traversed portions of the central South Indian Ocean for a few days
  in the middle of April.   An area of convection was located on 9 Apr
  generally between Christmas and Cocos Islands within an area of
  troughing accompanied by strong convergence.   The disturbed weather
  moved westward over the next few days and scatterometer data on the
  10th revealed a LLCC.   By 12 Apr the system was approaching 90E and
  convection was still fluctuating near the LLCC.  Strong southeasterly
  flow was occurring along the southern periphery of the LLCC and the
  system was experiencing moderate vertical shear.   RSMC La Reunion
  (MFR) began issuing bulletins on the LOW as Tropical Disturbance
  #14 at 12/1800 UTC.  The disturbance by this time had entered the
  Southwest Indian basin and was located about 500 nm west of Cocos

     The system continued to move westward over the next couple of days
  with some slight strengthening on the 13th.      MFR upgraded the
  disturbance to a tropical depression at 13/0000 UTC, and a STWO from
  JTWC noted that there had been an increase in convective organization.
  However, on 14 Apr scatterometer data indicated a broad LLCC which
  was fully-exposed with isolated deep convection south of the center.
  At 14/0600 UTC MFR relocated the center about 115 nm to the east-
  northeast of the previous warning position.  Coverage was temporarily
  dropped six hours later as the system remained weak and disorganized;
  however, bulletins were re-instigated at 0600 UTC on 15 Apr as the
  disturbance was showing signs of regeneration.  JTWC issued a Formation
  Alert at 1000 UTC, noting that there had been a significant increase
  in areal coverage of convection and that the LLCC appeared to be
  located on the eastern edge of the deep convection.    Upper-level
  (200-mb) analysis indicated that the system was now located under
  a ridge.   At 1200 UTC MFR re-upgraded the disturbance to a tropical
  depression with 30-kt winds, and at 1800 UTC JTWC initiated warnings on
  TC-26S, estimating an initial MSW of 35 kts.   The depression by this
  time was located about 640 nm southeast of Diego Garcia and was moving
  west-southwestward at 10 kts.   Organization was still improving with
  deep convection wrapping around the LLCC.   A 15/2028 UTC TRMM pass
  depicted a convective band from southeast to west of the system with
  the LLCC located about 15 nm east of the convection.  Although under
  the upper-level ridge axis, the system was still experiencing some
  light to moderate vertical shear.

     TC-26S (or SIO #14) continued to move slowly to the west on 16-17
  Apr, more or less maintaining its intensity.   At 1200 UTC on the 16th
  MFR upgraded the depression to Tropical Storm Innocente, but six hours
  later downgraded it back to depression status.  A SSM/I pass at 17/0310
  UTC indicated that the LLCC was beneath the northwestern edge of a
  convective band.  By 17/1800 UTC the system was located about 600 nm
  south-southeast of Diego Garcia, moving west at 5 kts, and had
  continued to slowly become better organized.   JTWC increased the
  MSW estimate to a peak value of 45 kts, and MFR upgraded the depression
  back to Tropical Storm Innocente with 10-min avg winds of 35 kts.
  Innocente displayed a broad LLCC with a weak band of convection around
  the southern side.   On 18 Apr the moderate tropical storm moved slowly
  on a west-southwesterly course and by late in the day was showing signs
  of weakening.     At 1800 UTC there was only intermittent convection
  blowing up near the center and JTWC decreased their MSW estimate to
  35 kts.        At 19/0000 UTC MFR downgraded Innocente to a tropical
  depression once more, and JTWC issued its final warning at 0600 UTC.
  There was no convection associated with the fully-exposed LLCC and
  the system had moved south of the subtropical ridge axis and was
  experiencing increased vertical shear.  MFR wrote their final warning
  on Innocente six hours later with the weakening center located about
  400 nm east-northeast of Rodrigues Island.   The residual LOW remained
  for several days with occasional flare-ups of convection but never
  showed any signs of redevelopment.


  AUSTRALIAN REGION (AUG) - From Longitude 90E Eastward to Longitude 160E

  Activity for April:  2 tropical LOWs
                       2 tropical cyclones of storm intensity
                       2 severe tropical cyclones (hurricanes)

     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 reports he
  had written for some of the cyclones; and Jeff Callaghan of the
  Brisbane TCWC sent me a considerable amount of information on Cyclones
  Tessi and Vaughan and the two Coral Sea LOWs at the end of the month.
  A special thanks to all these folks for their assistance.

  A description of the Australian Cyclone Severity Scale can be found in
  Chris Landsea's FAQ on HRD's website:>

  on Michael Bath's Australian Severe Weather site:>

  or on the Australian Bureau of Meteorology's official website:>
     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:>

  Links to various reports and map animations can be found under the
  link 'TC Reports & Map Animations'.

                   Australian Region Activity for April

     April turned out to be one of the most active months of the 1999 -
  2000 season in the Australian Region.      Two very intense tropical
  cyclones, Paul and Rosita, formed in the Perth AOR with Paul moving
  harmlessly out into the Indian Ocean while Rosita made landfall near
  Broome as a severe Category 4 cyclone.    Very early in the month two
  midget cyclones, Tessi and Vaughan, popped up in the Coral Sea and
  menaced the Queensland coast with Tessi causing substantial damage
  in the Townsville area while Vaughan collapsed and dissipated very
  quickly near Cairns.     Late in the month and into early May, two
  tropical LOWs formed in the Coral Sea, moved eastward into the Fiji
  AOR thereby receiving a number from the Nadi TCWC, then returned into
  Australian waters and approached the Queensland coast.   Since reports
  of gales were widespread with these systems, I have given them special
  coverage below.

                     Tropical Cyclone Tessi  (TC-22P)
                            31 March - 2 April

     A STWO issued by JTWC at 0600 UTC on 31 Mar indicated that an area
  of convection had formed in the Coral Sea well southeast of New Guinea
  or roughly 600 nm east of Cooktown, Queensland, and had persisted for
  twelve hours.      Animated satellite imagery revealed persistent
  convection with some degree of organization.   A 31/0000 UTC synoptic
  analysis indicated strong gradient flow southwest of the convection
  and CIMSS charts indicated low to moderate vertical shear.    The
  disturbance was given a Fair potential to develop into a significant
  tropical cyclone.   The Brisbane TCWC also began issuing gale warnings
  on the LOW at 31/0600 UTC.

     The developing tropical LOW continued to move west-southwestward
  toward the Queensland coast throughout 31 Mar, gradually getting better
  organized, and was upgraded to Tropical Cyclone Tessi with 40-kt winds
  at 0000 UTC on 1 Apr when the center was located approximately 530 nm
  east of Cooktown.  A convective band had developed over the northeast
  quadrant, and a 31/2251 UTC SSM/I pass showed convection wrapping in
  toward the LLCC from the southwest.      At 1200 UTC both JTWC and
  Brisbane were estimating winds at 40 kts and the cyclone's appearance
  continue to improve in organization.

     Cyclone Tessi continued moving at about 10 kts toward the Queensland
  coast and made landfall on 2 Apr around 2030 UTC about 20 nm south of
  Lucinda.  This storm was a midget cyclone which formed in the low-
  level easterlies in the absence of any monsoon westerlies.   According
  to a report on the storm from Jeff Callaghan of BoM Brisbane, at
  2300 UTC on 31 Mar the radius of the 1008-mb isobar was about 165 nm.
  Twenty-four hours later the 1008-mb isobar had shrunk to a radius of
  80 nm, and by the time of landfall had a radius of only 35 nm, thus
  indicating how environmental pressures around the vortex rose as the
  cyclone intensified.  Tessi formed a small, compact radar eye with a
  diameter of about 5.5 nm when it was near the coast around 1800 UTC on
  2 Apr.  In the cyclone's southern semicircle gales were reported as
  far south as Gumlu (about 120 km southeast of Townsville), which would
  imply a gale radius of about 100 nm; however, on the northern side
  gales extended outward from the center only about 16 nm.   At Gumlu an
  anemometer failed at 60 kts. (It was a pressure tube anemometer at
  a height of 6.5 m above the ground.)

     The Australian Institute of Marine Science (AIMS) maintains an AWS
  on Magnetic Island (about 15 km or 8 nm northeast of the Townsville
  Meteorological Office), and some data from this site was received
  later and passed along to me by Jeff.   The AWS measured a 10-min avg
  easterly wind of 59 kts at 02/1600 UTC which, in conjunction with
  some other data, indicates that Tessi's center was about 40 km (22 nm)
  from Townsville at its closest approach.

     Tessi set several new weather records for the month of April at the
  Townsville Meteorological Office:  highest wind gust (70 kts), highest
  daily rainfall (271.6 mm), and the highest monthly rainfall (539 mm
  as of 27 Apr).   Normal daily rainfall records are taken from 9AM to
  9AM local time; however, 423.4 mm was measured in the 24-hour period
  ending at 1AM (local time) on 4 Apr.  The maximum wind gust occurred
  at 02/1540 UTC when the center of the cyclone was about 33 nm away.

     The worst wind damage in settled areas occurred just outside the
  eye in the area around Mutarnee, a small village 60 km northwest of
  Townsville.      Many large trees were uprooted and the roof of a
  farmhouse was lifted off, battens and all, and deposited in a cane
  field about 60 m away.  The most extensive tree damage was farther
  east in the normally uninhabited beach areas where some isolated
  beach huts were unroofed.  The eyewall passed over this uninhabited
  area consisting mainly of marsh land.  The damage in this vicinity
  was confined to the immediate coastal area.  Bambaroo, which lies
  14 km northwest of Mutarnee and a little farther inland, suffered no
  damage.   After 2000 UTC the eye began to dissipate quickly and Tessi
  was rapidly weakening as the center made landfall.

     In the Townsville area the cyclone caused widespread wind damage,
  mainly to trees and power lines with about 35,000 persons left without
  power.   Most structural damage was due to falling trees though there
  were isolated reports of roof damage attributed directly to the wind.
  Widespread flooding occurred with the associated downpour, and there
  was a severe landslide in one of the more affluent residential areas
  on Castle Hill.  There was also some wave damage with several boats

     Warnings from JTWC and Brisbane were in pretty good agreement with
  regard to position but not with intensity.     As was the case with
  Cyclone Steve back in February, JTWC's peak MSW estimate was actually
  lower than Brisbane's maximum 10-min avg wind estimate.   Brisbane
  was reporting 50 kts as the cyclone neared the coast whereas JTWC's
  peak MSW estimate was 45 kts.  (The 02/1200 UTC JTWC warning did
  indicate that at least one Dvorak intensity estimate of 55 kts had
  been received.)   Again, as with Steve, radar and synoptic observations
  along the coast seem to confirm that Tessi was somewhat stronger than
  its appearance in satellite imagery suggested.

                Tropical Cyclone Vaughan  (TC-23P / TD-17F)
                            28 March - 7 April

     Like Tropical Cyclone Tessi, Vaughan was a midget tropical cyclone
  which formed in the low-level easterlies in the absence of any monsoon
  westerlies.   A very broad area of convection had developed northwest
  of Fiji by 0600 UTC on 27 Mar near 14S, 172E.    Synoptic analysis
  indicated a weak LLCC associated with the convection with CIMSS charts
  indicating the area was under weak to moderate vertical shear.
  Twenty-four hours later the main area of convection was about 300 nm
  farther to the west, or about 600 nm west of Fiji.  Animated multi-
  spectral satellite imagery depicted poorly-organized convection forming
  along the tail end of a weak shear line extending from New Caledonia
  to Fiji with a weak LLCC centered over Vanuatu.  The disturbance was
  located under the subtropical ridge axis and a 27/1855 UTC QuikScat
  pass showed convergent flow north of the shear line.

     Fiji began mentioning the system in their daily Tropical Weather
  Summary at 28/1800 UTC, numbering it as Tropical Disturbance 17F.
  The area remained quasi-stationary for a couple of days roughly 150 nm
  south-southwest of Port Vila in Vanuatu.   The STWO issued by JTWC at
  29/0600 UTC indicated that convection was still poorly organized and
  displaced east of the LLCC which was located within a northwest-
  southeast oriented surface trough under moderate vertical shear.
  Convection increased some on 30 Mar with a 200-mb analysis indicating
  a diffluent region over the area.      JTWC upgraded the development
  potential to Fair while Nadi classified the system as a tropical
  depression and issued three gale warnings, mainly in the anticipation
  that gales would develop.

     On 1 Apr the depression began to move slowly to the northwest
  toward an environment more favorable for intensification.   Early on
  2 Apr the system showed some signs of weakening and JTWC downgraded
  the development potential to Poor.     However, by 1800 UTC animated
  satellite imagery showed convection rapidly building over the LLCC so
  the development potential was once more upgraded to Fair.   The Nadi
  TCWC issued a new gale warning at 02/2100 UTC with the center of the
  depression located on the boundary of the Brisbane AOR.  JTWC issued
  a Formation Alert at 1930 UTC, noting that the system was quite small
  in areal extent (90 nm) with maximum winds estimated at 20-25 kts.  A
  200-mb analysis indicated that the system was moving under the
  subtropical ridge.    Brisbane took over warning responsibility as
  the depression crossed 160E and forecast gales to 40 kts in the
  southern semicircle.

     JTWC issued their first warning at 03/0000 UTC with MSW estimated
  at 35 kts.   TC-23P was a small, symmetrical system with associated
  cloud lines moving in toward the center from the northwest.  The LOW
  continued to display increased convective organization and Brisbane
  named the system Tropical Cyclone Vaughan at 1800 UTC with peak 10-min
  avg winds estimated at 40 kts.    By 04/0000 UTC deep convection had
  organized around the LLCC, and Brisbane increased the maximum winds to
  50 kts while JTWC's estimated MSW jumped to 55 kts based on current
  intensity estimates of 35 and 55 kts.  Vaughan at this time was located
  about 575 nm east-northeast of Cairns, moving west at 11 kts.    In
  their 1200 UTC warning JTWC decreased the MSW to 45 kts but Brisbane
  maintained Vaughan's intensity at 50 kts.    Convection had weakened
  significantly earlier but had made a comeback during the previous
  six hours.

     At 0000 UTC on 5 Apr JTWC further dropped the MSW to 40 kts while
  Brisbane increased the 10-min avg estimate to 55 kts!  The center of
  the cyclone by this time was located about 350 nm east-northeast of
  Cairns and moving toward the west-southwest at 10 kts.     Animated
  infrared imagery indicated that convection was cycling between periods
  of intensification and weakening.   At 1200 UTC JTWC reported the
  MSW at 35 kts while Brisbane maintained Vaughan's intensity at 55 kts.
  Animated infrared and microwave imagery indicated that the convection
  had essentially dissipated between 0000 and 1200 UTC.   Around 1400 UTC
  there was a massive blowup of convection over the center with cloud
  tops colder than -80 C.    Willis Island and Cairns radars showed an
  eye developing shortly afterward as did TRMM 85 GHz data from a pass
  at 2132 UTC.   At 1700 UTC Holmes Reef (WMO 94289) reported gales when
  the center was about 80 nm distant.  BoM Brisbane thought that Vaughan
  was rapidly intensifying to hurricane intensity and upped the 10-min
  avg winds to 60 kts at 1800 UTC.  JTWC, however, only increased their
  1-min avg MSW estimate from 35 to 40 kts.    This intensification was
  short-lived, however, as the mid-level vortex (which was being steered
  by a 500-mb ridge) left the low-level center behind.   Vaughan rapidly
  collapsed just off the Queensland coast east of Cooktown.     The
  maximum 10-min avg wind estimate dropped from 55 kts at 06/0100 UTC to
  30 kts at 0600 UTC.

     While JTWC tracked a low-level center inland through 07/0000 UTC,
  information from Jeff Callaghan indicates that coastal observations
  showed a 500-mb center southwest of Cairns at 06/1100 UTC while
  reports from Bougainville Reef (WMO 95288) placed the low-level center
  still out to sea near that station.    The JTWC warning issued at
  06/1200 UTC mentioned that a 06/1120 UTC SSM/I pass depicted extremely
  sparse deep convection with no clearly discernible LLCC.

     It is obvious that there were greatly divergent interpretations of
  satellite imagery of Tropical Cyclone Vaughan by the different warning
  agencies, and by other interested parties.   Pete Donaldson, of the
  Central Pacific Hurricane Center, sent around a visible satellite
  image taken at 04/2130 UTC in which he felt that a small, cloud-filled
  eye could be seen near the center of a small CDO, and that this feature
  represented the LLCC of Vaughan rather than exposed outside of the CDO.
  Roger Edson, however, disagreed with this assessment, stating that he
  could not see any sign of an eye in the image in question.   Roger
  supplied a TRMM 37 GHz image from 04/1300 UTC (courtesy of Jeff
  Hawkin's NRL Tropical Page) which showed the center of the circulation
  near the edge of a large convective area.   Roger contended that the
  2130 UTC visible image revealed a partially-exposed LLCC on the
  southern edge of the CDO with the same low-level cloud lines seen
  consistently throughout the day.   One final e-mail from Pete implied
  that Mark Lander was in agreement with the assertion that a tiny and
  indistinct eye had been visible intermittently from 04/2130 UTC through
  at least 05/0332 UTC, but the author personally has not received any
  e-mail from Mark concerning this cyclone.

     Based upon the intensity estimates from Brisbane and JTWC, it seems
  fairly obvious that the Brisbane TCWC must have felt that the center
  of Vaughan was imbedded within the CDO while the JTWC analysts
  interpreted the imagery more in line with Roger's assessment since
  their MSW estimate was lowered during the period in question.  Dvorak
  numbers from KGWC also indicated a weakening system during this time

     The other instance where JTWC's and Brisbane's intensities were
  greatly divergent was the eleventh-hour blowup of convection beginning
  around 05/1400 UTC (mentioned above) shortly before the cyclone began
  to collapse.  A Satellite Bulletin from KGWC at 05/2120 UTC noted that
  convection had developed rapidly near the center during the past 4 to
  6 hours but the T-number was 2.0.       It seems likely that the
  appearance of an eye on the Willis Island and Cairns radars (also
  mentioned above) was the primary basis for Brisbane's increasing the
  intensity of Vaughan to 60 kts.

     The author would like to point out that the above discussion of the
  varying interpretations of satellite imagery by the warning agencies
  involved and by other tropical meteorologists should not be construed
  as criticism of any person or warning center, nor as an attempt to
  imply who may or may not have been correct in their assessment of
  Vaughan's intensity.   Rather, my purpose was simply to underscore
  the inherent uncertainty often encountered in estimating the intensity
  of tropical cyclones by remote sensing, especially with midget cyclones
  such as Vaughan (and also Tessi).  Perhaps some more studies will be
  made of this interesting tropical cyclone in an attempt to better
  estimate its actual intensity.   If I should receive any further
  information on Tropical Cyclone Vaughan, I will report it in a future

                  Severe Tropical Cyclone Paul  (TC-24S)
                              13 - 22 April

     The most intense tropical cyclones in the South Indian Ocean this
  season seem to have come in pairs:  Leon/Eline and Hudah both formed
  in the western portion of the Australian Region and moved on westerly
  trajectories for thousands of miles, eventually wreaking much havoc
  in Madagascar and Mozambique; John and Rosita formed in the Timor
  Sea and struck the Western Australian coastline as intense cyclones;
  and Norman and Paul both formed off northwestern Australia, moved
  westward out into the Southeast Indian Ocean while attaining great
  intensity, and then weakened just shy of reaching the boundary of the
  Southwest Indian basin.

     A STWO issued by JTWC on 10 Apr at 1800 UTC indicated that an area
  of convection had formed about 160 nm west of Darwin (near 12S, 128E).
  Animated infrared satellite imagery indicated improving convective
  organization, and a QuikScat pass indicated a broad LLCC with a
  secondary center over land near 17S, 127E.     A 200-mb analysis
  indicated a favorable environment for strengthening.   By 12 Apr the
  area of convection had moved westward over the Timor Sea with deep
  convection beginning to wrap into the LLCC.   CIMSS analysis indicated
  the system was under an upper-level anticyclone with weak vertical
  shear and the system was given a Fair potential for development.  JTWC
  issued a Formation Alert at 1730 UTC.    At this time convection was
  starting to wrap around the northwest quadrant and maximum winds were
  estimated at 25-30 kts.

     Both Perth and JTWC initiated warnings on the intensifying system
  early on 13 Apr.   At 0100 UTC the first shipping warning from Perth
  placed the center of the LOW about 500 nm north of Exmouth.  The LLCC
  was still partially exposed with bands of convection wrapping in from
  the west side.   The LOW tracked west-southwestward fairly quickly
  (at 18 kts) and at 1000 UTC was upgraded to Tropical Cyclone Paul
  with 45-kt winds and located about 450 nm north-northwest of Exmouth.
  Convection continued to consolidate around the LLCC and by around
  14/0000 UTC Perth and JTWC were estimating the MSW at 50 kts (10-min
  avg) and 55 kts (1-min avg), respectively.   Paul was moving westward
  at 13 kts at this time, but the cyclone's motion began to tend more
  to the west-northwest with time.

     The storm underwent a period of rapid intensification on the 14th
  with Perth assessing the peak 10-min avg winds at 70 kts at 1000 UTC,
  and JTWC's MSW estimate reached 90 kts at 1200 UTC.   A 10-nm diameter
  eye had become apparent in infrared imagery by this time.   Paul's
  center was located approximately 300 nm south-southeast of Christmas
  Island at the time it reached severe tropical cyclone (hurricane)
  intensity.   The intensification trend continued with Paul reaching
  its estimated peak intensity of 110 kts (10-min avg) and 125 kts
  (1-min avg) around 1000 UTC on 15 Apr.  Steered by a strong subtropical
  ridge to the south, the cyclone was moving on a west-northwesterly
  track at this time and was centered roughly 350 nm east-southeast of
  Cocos Island.   A SSM/I pass at 15/1108 UTC indicated a well-defined
  eye 10-nm in diameter with a banding feature wrapping in toward the
  LLCC from the south.   At Paul's peak intensity gales extended outward
  120 nm to the south and 75 nm elsewhere.  The radius of 100-kt winds
  was estimated to be 20 nm.  The minimum central pressure in the storm's
  history per Perth's analysis was 920 mb from 15/1000 UTC through
  16/2200 UTC.

     Paul maintained its peak intensity through around 2200 UTC on
  16 Apr.  Even as early as 16/0000 UTC the eye had become cloud-filled
  and the cyclone's appearance was less symmetric.    By 1200 UTC eye
  temperatures had cooled somewhat and cloud tops had warmed.   The
  storm began to track slightly to the west-southwest as indirect
  interaction with Tropical Storm Innocente (TC-26S) southeast of Diego
  Garcia had weakened the peripheral ridge situated between the two
  systems.   Severe Tropical Cyclone Paul passed about 125 nm south of
  Cocos Island around 0700 UTC on 17 Apr.    Winds were down to 100 kts
  at this time (120 kts MSW from JTWC) and the storm began to weaken
  fairly quickly thereafter.   The JTWC warning at 17/1200 UTC noted
  that the intense convection was confined to the northwest quadrant.

     By 17/2200 UTC Perth's intensity estimate had dropped to 90 kts.
  JTWC reported the MSW at 105 kts at 18/0000 UTC and the warning noted
  that SSM/I imagery indicated a very tightly-wrapped LLCC but with
  the intense convection limited to the well-defined eyewall.  Paul's
  forward motion had become quite slow, generally toward the west.
  By 19/0000 UTC satellite imagery revealed that the cyclone was becoming
  elongated along a northwest-southeast axis.   The Perth TCWC dropped
  the 10-min avg winds to 55 kts at 1000 UTC and JTWC's MSW estimate
  had fallen to 65 kts by 1200 UTC.   Paul's center was located about
  200 nm southwest of Cocos Island at this time.

     The storm continued to steadily deteriorate.   A 19/2310 UTC SSM/I
  pass depicted a partially-exposed LLCC with weak convection located
  south to west of the center.  Perth wrote their final shipping warning
  at 20/0400 UTC as gales were no longer forecast.  JTWC continued to
  issue warnings on Paul through 21/1200 UTC.     Upper-level south-
  easterlies generated by a ridge southwest of Paul continued to displace
  convection to the northwest of the LLCC.   A TRMM pass at 21/0821 UTC
  depicted a broad, exposed LLCC with associated isolated convection
  located 45 nm to the east and 130 nm to the northwest of the center.
  JTWC's final warning at 1200 UTC placed the weakening center about
  335 nm southwest of Cocos Island with 35-kt winds and moving slowly
  westward at 5 kts.  The remnants of Paul continued to drift westward
  across 90E and occasionally some convection would flare up, but the 
  system never made any serious attempt at re-intensification.

                  Severe Tropical Cyclone Rosita  (TC-27S)
                               15 - 21 April

     Back in December Severe Tropical Cyclone John ushered in the
  cyclone season in Western Australia with a bang, making landfall
  west of Port Hedland near Whim Creek as a Category 5 cyclone on
  the Australian Cyclone Scale.     In April Cyclone Rosita concluded
  the season with only a slightly lesser bang, moving inland near
  Broome as a Category 4 cyclone.   The Perth TCWC mentioned a tropical
  LOW in their daily Tropical Weather Outlook issued at 0400 UTC on
  15 April.  The weak LOW was located about 360 nm north of Broome.
  In their STWO at 1800 UTC, JTWC indicated that convection had persisted
  for over twelve hours and that animated water vapor imagery showed
  improving outflow.  A 15/1008 UTC QuikScat pass revealed a well-defined
  LLCC.   Perth began issuing regular shipping warnings at 0400 UTC on
  the 16th with the LOW's center located about 300 nm to the west of its
  position of 24 hours earlier.  

     The LOW drifted very slowly during the next day or so.  At 1600 UTC
  Perth relocated the center to about 85 nm southeast of the previous
  warning position.   JTWC issued a Formation Alert at 17/0000 UTC with
  the system exhibiting a partially-exposed LLCC located on the northern
  edge of the deep convection.     Infrared satellite imagery depicted
  steadily improving organization with some deep convection beginning to
  wrap into the LLCC from the northwest.  The first warning from JTWC
  was issued at 0600 UTC for a 35-kt system drifting slowly southward
  at 3 kts.  Deep convection had increased in areal coverage with two
  symmetric areas of convection to the north and south of the LLCC.
  Perth upgraded the LOW to Tropical Cyclone Rosita with 45-kt winds
  at 17/1000 UTC, placing the center about 275 nm northwest of Broome.
  JTWC upped their MSW estimate to 50 kts at 1800 UTC, noting that
  Rosita had intensified rapidly and had moved southwestward at 14 kts
  during the previous six hours.

     After this initial rapid intensification, Rosita's winds reached a
  plateau for about a 24-hour period.  The cyclone moved very slowly to
  the south, later turning to the southeast.   Around 18/0600 UTC the
  cyclone was moving through a weakness in the subtropical ridge and
  still exhibited a partially-exposed LLCC although with good upper-
  level outflow.  Convection continued to increase in organization around
  the LLCC and at 2200 UTC Perth abruptly increased the maximum 10-min
  avg wind estimate to 70 kts with Rosita's center located about 135 nm
  west-northwest of Broome.   JTWC increased their MSW estimate to 90 kts
  at 19/0600 UTC with the cyclone now moving east-southeastward at 6 kts.
  A 14-nm diameter eye had formed and a 19/0126 UTC SSM/I pass indicated
  deep convection within the eyewall.

     Severe Tropical Cyclone Rosita reached its peak intensity of 105 kts
  (10-min avg) with an attendant CP estimated at 930 mb at 1000 UTC on
  19 April when the cyclone's center was only 70 nm west-northwest of
  Broome.   JTWC assigned a peak MSW (1-min avg) of 125 kts just before
  the cyclone made landfall at 1630 UTC about 25 nm south-southwest of
  Broome, tracking east-southeastward at 9 kts.   A 19/1548 UTC TRMM
  pass showed a symmetric eyewall with a banding feature west of the eye.
  A loop from the Broome radar indicated a slight decrease in intensity
  but very little change in the eyewall structure in the 1-1/2 hours
  following landfall.   Rosita weakened rapidly following landfall and
  Perth issued the last advice at 20/0400 UTC, placing the weakening
  system with 35-kt winds about 135 nm southeast of Broome.   JTWC
  issued its final warning at 0600 UTC, noting that the only deep
  convection remaining was confined to a small area just south of the
  LLCC.   At 0400 UTC on 21 Apr Rosita was a rain-bearing depression
  located about 450 nm south of Darwin and moving east-southeastward.

     Broome fortunately escaped the worst of Rosita's fury.  The maximum
  wind gust recorded in the town was 77 kts compared to 130 kts (likely
  estimated) near the cyclone's center.      Seas off the coast were
  mountainous with residents saying they had not seen such conditions
  in 14 years.    About 250 people were relocated from the Bidyadanga
  Community, south of Broome, to Port Hedland.   In the Broome area most
  power lines were down, and several boats broke loose from their
  moorings at the height of the storm.       At Broome's only banana
  plantation, the crop was almost completely lost with only about 10
  plants left out of 18,000.  (Most of the information in this paragraph
  was taken from an Australian Broadcast Corporation news bulletin and
  passed along to the author by Carl Smith.)

                 Coral Sea Tropical LOWs  (TD-21F & TD-20F)
                   26 April - 2 May  &  28 April - 2 May

     During the final days of April and into early May, two tropical LOWs
  (i.e., depressions) performed an interesting dance around the Coral
  Sea.   Gale-force winds were reported in the southern semicircle of
  both systems due to a tight pressure gradient with a HIGH to the south,
  but neither acquired the structure of a tropical cyclone.  (This was
  consistent with satellite intensity estimates from JTWC and KGWC with
  a Dvorak T2.0 being the highest rating given to either LOW.)     The
  lion's share of the information given below on these LOWs was provided
  by Jeff Callaghan of the Brisbane TCWC with some supplemental data
  from Matthew Saxby of Queanbeyan, NSW.    A special thanks to Jeff and
  Matthew for sending me the information.

     Over the period 26-27 Apr a large 1034-mb HIGH moved into the Tasman
  Sea.  A marked upper-level trough extended into far northern Queensland
  and a small tropical LOW formed under a diffluent wind pattern between
  upper northwest winds ahead of the trough and upper-level southeasterly
  flow towards New Guinea.  The intense pressure gradient between the LOW
  and the HIGH generated gales in the Cairns area.    The LOW became
  quasi-stationary for a time on 27 Apr roughly 150 nm north of Cairns
  and became quite deep as a 26/2300 UTC RAWIN showed winds to 52 kts at
  850 and 800 mb.   Above 600 mb winds turned northwesterly under the
  influence of the upper-level trough and convection which had formed
  moved off to the southeast, preventing further development.   Green
  Island AWS (WMO 95289) reported almost continual gales from 26/0530 to
  27/1248 UTC with a maximum 10-min wind of 43 kts, and Low Isle AWS
  (WMO 94285) reported continual gales from 26/1700 to 27/1100 UTC with
  a peak 10-min wind of 41 kts.   A trawler with a crew of 3 sank near
  Norman Reef northeast of Cairns but the crew was rescued.   A family
  of 6 was rescued by helicopter from a remote beach 32 km southeast of
  Cairns after the heavy seas forced them to beach their power boat.  In
  addition the chopper crew rescued 13 people from a flooded campground
  west of Cairns.

     The diffluent pattern east of the upper-level trough which helped to
  form the Cairns LOW moved out into the Coral Sea and triggered a mass
  of convection.   A surface LOW formed to the west of this convection
  and by 28/0000 UTC QuikScat data indicated gales under the convection
  to the east.   The LOW moved towards the southeast as the mid- to
  upper-level trough became quite involuted to the south.     The LOW
  passed to the north of Ile Loop AWS (WMO 91574) where east-southeast
  winds of 36 kts were reported at 29/0700 UTC, and later near Ile
  Surprise AWS (WMO 91570) where winds reached 32 kts at 1100 UTC.  The
  lowest pressure of 998.3 mb was recorded at 1600 and 1700 UTC.  With
  a 1034-mb HIGH centered over Auckland, a huge area of gales and near-
  gales were being directed from the Dateline towards the east coast of
  Australia.   The center of the LOW moved east of 160E after 0000 UTC
  on 29 Apr, reaching its easternmost location of 162E between 1200 and
  1800 UTC.  The TCWC at Nadi, Fiji, issued gale warnings on the system
  during this time and numbered it as Tropical Depression 20F.

     The cyclonic portion of the mid-level involution began moving north
  towards the LOW and the steering mechanism became the deep ridge to
  the south, thus turning the LOW westward toward Australia.    Some
  intensification occurred as the mid-level LOW began to couple up with
  the low-level center.   The system passed to the north of Cato Island
  (WMO 94394) where gales were reported generally between 2000 UTC on
  30 Apr and 0200 UTC on 1 May.  The peak 10-min avg wind recorded was
  44 kts at 30/2300 UTC while the lowest pressure of 999.5 mb occurred
  at 01/0200 UTC.  The LOW was becoming almost vertically stacked and
  was probably near peak intensity as it went past Cato Island.   Many
  ships reported gales with several reporting 10-min mean winds as high
  as 45 kts on 1 May.

     Several locations along the Australian coast reported winds in
  excess of gale force.  The highest 10-min avg wind appears to have been
  recorded at Double Island Point AWS (WMO 94584): 43 kts at 01/0351 UTC,
  while the highest gust recorded was 57 kts at Cape Moreton AWS (WMO
  94594) at 01/0832 UTC.    The Toowoomba AWS (WMO 94551), which is
  inland, reported mean winds of 33 kts with gusts to 41 kts at 1341 UTC
  on the 1st.  A visible satellite image of the LOW at 01/0131 UTC shows
  an exposed LLCC off the Queensland coast with an extensive area of
  lower clouds and fairly shallow convection to the southeast.
  Fortunately the LOW made landfall as a weak system and caused little
  wind damage and no heavy rain.  There was serious beach erosion on
  Fraser Island and in the Sunshine and Gold Coast tourist areas.  Peak
  wave heights of 7.4 m were reported on the Gold Coast and reached 
  8.1 m and 9.7 m at Tweeds Head and Brisbane, respectively.

     Turning back to the Cairns LOW of 26-27 Apr--after the 27th this
  first LOW became detached from the surface trough and was tracked as
  a vorticity feature on satellite imagery moving initially northwestward
  but later turning eastward.  QuikScat winds at 29/2007 UTC showed gales
  on its southern side with a center near 13S, 153E.  The small LOW was
  rapidly moving within the deep westerlies north of the deep cyclonic
  circulation to its south.  It made it as far east as 161E by 2100 UTC
  on 30 Apr where Fiji designated it as Tropical Depression 21F.  The LOW
  then moved around the periphery of the larger circulation and headed
  westward toward Australia.     Just as the other LOW (TD-20F) was
  weakening and crossing the coast, TD-21F replaced it about 110 nm
  north of Cato Reef at 02/0000 UTC.  The LOW kept the gales going to
  the south for another 24 hours before it too made landfall as a weak
  system about 80 nm (150 km) north of where the first LOW had landed.


  SOUTHWEST PACIFIC (SWP) - South Pacific Ocean East of Longitude 160E

  Activity for April:  3 tropical depressions
                       1 tropical cyclone of gale intensity

     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 report on Tropical Cyclone Neil was 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 summary and the cyclone's track.

                    Southwest Pacific Activity for April

     Several tropical systems roamed the waters of the South Pacific east
  of 160E during April but most were quite weak.  The only named cyclone
  was Neil, which formed around mid-month near Fiji and caused some heavy
  rains and marginal gales in the islands before moving off to the south-
  southeast.     A system on 5 and 6 Apr was referred to as a tropical
  depression in two Tropical Disturbance Summaries but was not assigned
  a number.  This depression formed just east of the Dateline east of
  Fiji and appeared to have been severely sheared with little real
  potential for development.    No track is given for this system.
  A disturbance formed west of Tahiti from an upper-level cutoff LOW
  on 10 Apr and moved west-southwestward for a couple of days.  This LOW
  was designated 18F but was never referred to as a tropical depression.
  Finally, at the end of the month two tropical LOWs (depressions) from
  the Australian Region moved eastward across 160E and were numbered 20F
  and 21F before moving back westward into Brisbane's AOR.  Since the
  primary impact of these LOWs was to Australia, they are covered in the
  discussion of activity for the Australian Region.

                 Tropical Cyclone Neil  (TC-25P / TC-19F)
                              15 - 17 April

     Tropical Cyclone Neil was the sixth cyclone to form in RSMC Nadi's
  AOR this season.  A disturbance was first identified embedded in a
  slow-moving trough of low pressure just northeast of Fiji around
  12/1200 UTC.  At this stage the trough, along with the disturbance,
  was drifting slowly southwestward towards Fiji.  After 13/0600 UTC
  the system had developed into a tropical depression while located some
  60 nm northeast of Vanuabalavu island with convection immediately
  around the centre increasing.   Though it was then located just south
  of the 250-mb ridge, shear was still minimal.  Overall organisation
  had not changed much by 14/0000 UTC, even though deep convection
  appeared weakly sheared to the east.   Twenty-four hours later, the
  depression had moved further southwest with convection increasing and
  becoming better organised around the LLCC.  Good outflow in certain
  sectors was also established as the system was now located under the
  250-mb ridge axis with good diffluent flow over it.   A warm SST of
  around 30 degrees Celsius certainly enhanced the system's potential
  to reach tropical cyclone intensity within the next 24 hours.

     At 15/1200 UTC, in the second Tropical Disturbance Advisory issued
  by RSMC Nadi, the potential for development to a cyclone within 12
  to 24 hours was raised to "high" as all factors became more
  favourable, though convection was still undergoing some diurnal
  variation.   At this time the depression was located about 60 nm
  southeast of Kadavu and slow-moving, but anticipated to move further
  southwards.   Through the early hours of the morning of the 16th,
  (Local) the depression further intensified with convective tops
  cooling and organisation improving significantly.  At 15/1700 UTC,
  the depression was named Tropical Cyclone Neil while located some
  80 nm southeast of Kadavu and still slow-moving.

     Through the 16th (Local), Neil was subjected to increasing westerly
  shear as it began to move southward at about 06 kts which effectively
  displaced the deep convection about 30 to 40 nm southeast of the LLCC.
  Shear was reinforced by a deep 250-mb trough upstream of the cyclone.
  After 16/0600 UTC it was apparent that shear over the system was only
  going to increase further and that the steering field would move it
  rapidly into cooler waters, thus demolishing any organisation that
  would have prevailed.     Hence, at 16/1200 UTC, the system was
  downgraded to a tropical depression with gales confined to within
  120 nm of the centre only in the southern semicircle, enhanced by
  an intense surface HIGH cell to the south.   Former Tropical Cyclone
  Neil finally exited Nadi's AOR after 17/1800 UTC as a depression with
  gales still confined to the southern semicircle.

     Damage attributed to Neil was minimal, with only marginal gales
  reported over the two southern-most islands in Fiji:  Kadavu and
  Ono-i-Lau.   Torrential rain was experienced over some parts of Fiji
  while strong winds affected most places.    There was one fatality
  due to drowning, but not directly associated with the 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: []
       (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
           April as an example:   apr00.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:  apr00.sum, for

    Back issues can also be obtained from the following websites
  (courtesy of Michael Bath, Michael V. Padua, Tom Berg, Michael
  Pitt, and Rich Henning):>>>>>

     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:>


     I have discovered that JTWC now has available on its website the
  complete Annual Tropical Cyclone Report (ATCR) for 1999 (1998-1999
  season for the Southern Hemisphere).  Also, ATCRs for earlier years
  are available.

     The URL is:>

     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:>

  Prepared by: Gary Padgett
  Phone:  334-222-5327 (nights & weekends) / 850-882-2594 (weekdays)


Document: summ0004.htm
Updated: 4th January 2007

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