Tropical Cyclones [Index]

Monthly Global Tropical Cyclone Summary May 1998 [Summaries and Track Data] [Prepared by Gary Padgett]

                 MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY

                               MAY, 1998

  (For general comments about the nature of these summaries, as well as
  information on how to download the tabular cyclone track files, see
  the Author's Note at the end of this summary.)


            EXTRA FEATURE - FILIPINO TROPICAL CYCLONE NAMES

     Many readers may be aware that for many years the Philippines'
  Atmospheric, Geophysical & Astronomical Services Administration, or
  PAGASA, has utilized Filipino names to identify tropical cyclones
  within their area of responsibility--from 115E to 135E, and from 5N
  to 25N (except for a portion of the northwest corner of this region).
  This practice dates back to 1963, when four sets of Filipino women's
  names ending in "ng" were created for the following reasons:

     (1) Names selected cannot be confused with JTWC's names--they are
         unique and applicable only to Philippine tropical cyclones.

     (2) Filipino names will indicate that the storm is within the
         forecast area of responsibility of PAGASA and would have a
         high probability of affecting the Philippines.

     (3) The Filipino alphabet has 19 letters, which is equal to the
         average number of tropical cyclones in the area of responsi-
         bility.

     (4) People in the rural areas easily remember these names.

     Names for 1998 tropical cyclones occurring in the PAGASA region of
  warning responsibility are:

     Akang, Bising, Klaring, Deling, Emang, Gading, Heling, Iliang,
     Loleng, Miding, Norming, Oyang, Pasing, Ritang, Susang, Tering,
     Uding, Weling, Yaning, Aning, Bidang, Katring, Delang, Esang,
     Garding

     Many thanks for David Michael V. Padua for supplying the above
  information.   Michael is the Internet Systems Administrator for
  Naga College Foundation, Naga City, Philippines.  He the author
  of an excellent typhoon webpage which contains archives of Western
  North Pacific tropical cyclone activity dating back to 1945.  The
  URL for Michael's page is:

             http://www.geocities.com/capecanaveral/6825

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                             MAY HIGHLIGHTS

  --> Northern Hemisphere's first cyclone of 1998 strikes Bangladesh

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                           ACTIVITY BY BASINS

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

  Activity for May:  No tropical cyclones

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

  Activity for May:  No tropical cyclones

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

  Activity for May:  No tropical cyclones

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

  Activity for May:  1 tropical cyclone of gale intensity
                     1 tropical cyclone of hurricane intensity


                    Tropical Cyclone 01B   18-20 May
                    --------------------------------

     The first tropical cyclone to form in the Northern Hemisphere in
  1998 began taking shape over the central Bay of Bengal on 17 May.  A
  Formation Alert was issued by JTWC around 0700 UTC concerning a circu-
  lation near 12.3N, 84.0E.   At 1600 UTC a second Formation Alert was
  issued advising that the area of interest had shifted northeastward
  to another circulation near 14.0N, 87.4E.   The first tropical cyclone
  warning was issued at 0600 UTC on 18 May, locating a depression with
  30-kt sustained winds (1-min avg) about 425 nm south of Calcutta, or
  about 450 nm south-southwest of Chittagong, Bangladesh.

     The system moved generally in a north-northeastward direction for
  most of its life.   Gale intensity was reached at 18/1800 UTC when
  the cyclone was centered about 300 nm south-southwest of Chittagong.
  Tropical Cyclone 01B continued to slowly strengthen as it moved into
  the upper reaches of the Bay of Bengal.   The storm was estimated to
  have reached minimal hurricane intensity of 65 kts around 0000 UTC on
  20 May when centered only about 50 nm south-southwest of Chittagong.
  A microwave imager pass indicated an eye had developed, and an amended
  warning re-located the center about 30 nm to the east of the original
  20/0000 UTC position.

     Tropical Cyclone 01B made landfall very near Chittagong around
  0600 UTC on the 20th and continued on its north-northeastward course
  farther inland.  The last JTWC warning, issued at 1800 UTC on 20 May,
  placed the center of the decaying depression about 150 nm northeast
  of Chittagong.

     Press reports indicated that 14 persons were killed and 200 injured
  by the storm with nearly 100 fishermen still reported missing a day
  after the cyclone struck.  More than 10,000 tin-roofed homes were
  flattened by the cyclone's winds which, according to the press report
  obtained by the author, reached 85 kts; however, it is not clear if
  these were measured or estimated, nor if this value represents 
  sustained winds or peak gusts.   There was also a report that a loaded
  oil tanker was sinking after being damaged in a collision with another
  ship in the storm.

     (Coincidentally, the first North Indian Ocean tropical cyclone of
  1997, also 01B, made landfall in the very same region on 19 May 1997.
  However, last year's cyclone was a much more intense system.  According
  to the Best Track information on JTWC's website, 01B-97 had estimated
  maximum sustained winds of 115 kts and a central pressure of 927 mb
  near landfall.)


                    Tropical Cyclone 02A   28-29 May
                    --------------------------------

     Tropical Cyclone 02A was a short-lived minimal tropical storm in
  the northern Arabian Sea in late May.    The first warning by JTWC,
  issued at 0000 UTC on 28 May, located the weak cyclone about 400 nm
  south of Masirah Island off the coast of Oman.  Scatterometer data had
  indicated an area of 35-kt surface winds near the center.   TC-02A
  was a small system and had apparently developed quite suddenly--the
  tropical weather outlook from the previous day had not mentioned any
  disturbance with a potential for cyclone development.  Even as the
  first warning was issued the cyclone was entering an area of increased
  vertical shear and was given little potential for further development.

     The second warning at 28/0600 UTC re-located the center about 90 nm
  to the east-southeast.  This was based on visible imagery which showed
  an exposed low-level circulation center.   The system remained quasi-
  stationary for about the next 6 hours, and then began a slow drift to
  the west or west-northwest.   At 1800 UTC the system was downgraded to
  a depression with 30-kt winds.   The Dvorak intensity estimate at this
  time was below warning criteria, but scatterometer data indicated
  slightly higher winds.   However, the system continued to deteriorate
  and by the time the last warning was issued at 29/0000 UTC, there was
  only a low-level center with little associated convection which was
  forecast to drift slowly northward and dissipate.

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

  Activity for May:  No tropical cyclones

     There were no tropical cyclones observed in the South Indian Ocean
  during May,  but the author did uncover a short report concerning
  a damaging windstorm which struck the Seychelles Islands.  The report
  indicated that some houses were damaged and roads blocked with fallen
  trees.   Power was cut off in many areas due to downed trees, and
  engineers estimated that it would take at least two days to restore
  full service to all areas.    The article mentioned that the storm
  struck without warning and was not associated with a tropical cyclone.
  
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  AUSTRALIAN REGION (AUG) - From Longitude 90E Eastward to Longitude 160E

  Activity for May:  No tropical cyclones

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

  Activity for May:  1 dissipating tropical cyclone of gale intensity


                ADDITIONAL INFORMATION for April Summary

     In the April cyclone summary I mentioned a casualty report for
  Tropical Cyclone Alan from the island of Tahaa with the remark that
  I had been unsuccessful in locating that particular island.  Ross Evans
  of the Darwin TCWC sent me an e-mail informing me that he had found
  Tahaa on a map.  Its location is 16.4 S, 151.3 W, between the islands
  of Raiatea and Bora Bora.   Thanks to Ross for that information.

     Steve Ready of the New Zealand Meteorological Service has sent me
  some damage and casualty figures for Tropical Cyclone Alan.  The death
  toll for Alan is set at 10 (5 deaths on Tahaa and 5 on Raiatea).  On
  Raiatea 150 homes were destroyed and on Tahaa 140 homes were partially
  or completely destroyed.   On the island of Huahine to the east of
  Raiatea, 430 homes were partially or completely destroyed.   On all
  three islands water and electricity were cut off; there were many
  fallen trees; mudslides blocked access to roads; and on Tahaa two
  bridges collapsed due to landslides.

     Alan has been categorized as one of the worst natural disasters
  experienced in French Polynesia, which lies outside the primary
  tropical cyclone belt during most seasons.  A special thanks to Steve
  for sending this information.


              Tropical Cyclone Bart (TC-37P)   28 April-3 May
              -----------------------------------------------

     Tropical Cyclone Bart, which had developed at the end of April, was
  still active into early May but was rapidly dissipating near the
  southeastern Tuamotu Islands. Following is an excerpt from last month's
  summary:

  .......................................................................

  Satellite imagery around 01/0000 UTC showed that the main convective
  area had been sheared about 60 nm to the southeast of the exposed
  low-level center.

     The system was downgraded to a depression at 0600 UTC on the 1st but
  some gales were still forecast to occur in the southern semi-circle.
  After 01/1200 UTC Bart began to accelerate again in more of an east-
  southeasterly direction. The last bulletin found the weakening system 
  about 50 nm north of Pitcairn Island around 0000 UTC on 3 May.

  .......................................................................

     For the full report on Tropical Cyclone Bart, refer to the summary
  for April, 1998.   The complete track of Bart can also be found in the
  Global Tropical Cyclone Tracks document for April.

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  AUTHOR'S NOTE:  This summary should be considered a very preliminary 
  overview of the tropical cyclones that occur in each month. The cyclone
  tracks (provided separately) will generally be based upon operational
  warnings issued by the various tropical cyclone warning centers.  The
  information contained therein may differ somewhat from the tracking and
  intensity information obtained from a "best-track" file which is based
  on a detailed post-seasonal analysis of all available data. Information
  on where to find official "best-track" files from the various warning
  centers will be passed along from time to time.

    The track files are not being sent via e-mail.  They can be retrieved
  in the following manner:

       (a) FTP to:  hrd-type42.nhc.noaa.gov [140.90.176.206]
       (b) Login as: anonymous
       (c) For a password use your e-mail address
       (d) The files will be named with an obvious nomenclature--using
           May as an example:   may98.tracks

    Both the summaries and the track files are standard text files
  created in DOS editor.  Download to disk and use a viewer such as
  Notepad or DOS editor to view the files.

    The May summary is the eighth cyclone summary in this series;
  the first one covering the month of October, 1997.  If anyone did
  not receive any of the previous summaries, they may be downloaded
  from the aforementioned FTP site at HRD.   The summary files are
  catalogued with the nomenclature:  oct97.sum, for example.

    Back issues can also be obtained from the following websites
  (courtesy of Michael Bath and Michael V. Padua):

    http://australiansevereweather.com/cyclones/>
    http://www.geocities.com/capecanaveral/6825> (since January only)

    The preliminary storm reports for all the 1997 Atlantic and Eastern
  North Pacific tropical cyclones are available on the Tropical
  Prediction Center's website:  http://www.nhc.noaa.gov> .  These
  reports include the analyzed best-track for each cyclone.  The staff
  of JTWC is also working on an on-line version of their Annual Tropical
  Cyclone Report for 1997.  It is still under construction, but the
  best-track files are already available for 1997 Northwestern Pacific
  and North Indian Ocean cyclones.  The URL is:

       http://www.npmocw.navy.mil/npmocw/prods/jtwc.html>

  Prepared by: Gary Padgett
  E-mail:  [email protected]
  Phone:  334-222-5327

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