Tropical Cyclones [Index]

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

                 MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY

                               JUNE, 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.)

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                             JUNE HIGHLIGHTS

  --> Deadly Arabian Sea cyclone devastates northwestern India
  --> Northeastern Pacific season gets underway a little late

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                           ACTIVITY BY BASINS

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

  Activity for June:  No tropical cyclones

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

  Activity for June:  1 tropical depression
                      1 tropical storm
                      1 hurricane


                 Tropical Storm Agatha (01E)   11-16 June
                 ----------------------------------------

     A tropical disturbance south of the Mexican coast slowly began
  getting better organized during the second week of June, and the first
  advisory on Tropical Depression 01E was issued by TPC/NHC at 1200 GMT
  on 11 Jun, locating the poorly organized center about 400 nm south of
  Manzanillo, Mexico.   Motion was erratic at first, but by 1800 GMT
  the next day the depression had begun to move on a west-northwesterly
  heading from which it never deviated.   This system was very slow to
  strengthen, but tropical storm intensity was finally achieved by
  13/0600 GMT and the depression was upgraded to Tropical Storm Agatha.
  The storm was centered at this time about 575 nm south of Cabo San 
  Lucas on the tip of the Baja California peninsula.
  
     Agatha reached a peak intensity of 55 kts maximum sustained winds
  with an estimated central pressure of 992 mb around 1800 GMT on
  13 Jun.  At this time Agatha was a well-organized tropical cyclone 
  with an impressive appearance in satellite imagery.   On 14 Jun the 
  cyclone began to weaken due to cooler sea surface temperatures and
  increasing vertical shear.    Agatha was downgraded to a weakening
  depression at 15/1800 GMT and the final advisory placed the residual 
  swirl of low clouds about 750 nm west-southwest of Cabo San Lucas at 
  1800 GMT on 16 Jun.   This tropical storm caused no direct effects on
  the Mexican mainland.   Some of the moisture from Agatha may have led
  to enhanced rainfall in the southwestern states of the United States.

     The 1998 Eastern North Pacific tropical cyclone season was a little
  later than normal getting underway.       Since 1966, when complete
  operational satellite coverage began for this region, the median date 
  for the beginning of the first tropical storm/hurricane has been
  1 June.   Of the thirty-two seasons from 1966 through 1997, the first
  cyclone formed in May in fifteen years--almost 50% of the time.  The
  earliest beginning season on record was in 1990, when Hurricane Alma
  formed on 12 May; while the latest season to begin was in 1969, when
  Tropical Storm Ava formed on 1 July.    Only six seasons have had a
  later starting date than 1998.


                  Tropical Depression 02E   19-22 June
                  ------------------------------------

     A slow-moving tropical disturbance which had been moving south of
  Central America and Mexico for a few days in mid-June began getting
  better organized on 19 Jun and the first advisory on Tropical
  Depression 02E was issued at 1800 GMT.   The center was estimated to
  be about 250 nm south of Manzanillo, in the same general vicinity
  where Agatha had begun.  This depression moved on a west-northwesterly
  course throughout its life, passing about 30 nm south of Socorro
  Island around 0600 GMT on 21 Jun.    The depression was initially
  forecast to strengthen into a tropical storm, but this did not verify.
  Discussions from TPC/NHC on 20 Jun indicated that it perhaps came
  close to reaching tropical storm intensity on that date.

     Although the center passed just south of Socorro Island, no strong
  winds were reported.   The depression began to weaken rapidly as it
  moved into a region of cooler sea surface temperatures and the final
  advisory, issued at 22/0000 GMT, placed the dissipating cyclone about
  325 nm southwest of Cabo San Lucas.   The estimated maximum sustained
  wind in this system was 30 kts with a central pressure of 1005 mb.


           
                   Hurricane Blas (03E)   22-30 June
                   ---------------------------------

     The first hurricane of the year in the North Pacific was a classic
  "textbook" example--forming in the warm waters south of the Mexican
  coast, moving on a fairly smooth west-northwesterly and westerly course
  away from the mainland, then weakening slowly as it encountered cooler
  sea surface temperatures.  The first advisory on Tropical Depression
  03E at 1200 GMT on 22 Jun placed the center of the developing system
  about 400 nm south of Salina Cruz, Mexico, in the region of the Gulf
  of Tehuantepec.  Just six hours later the depression was upgraded to
  Tropical Storm Blas with 45 kt winds.  Blas formed over a region of
  some very warm sea surface temperatures.   The TPC/NHC discussion
  for 23/0300 GMT mentioned some very cold (-80 C) convective tops over
  the low-level circulation center.

     Blas passed about 300 nm south of Acapulco at 1200 GMT on 23 Jun
  and was upgraded to a hurricane six hours later.    Hurricane Blas 
  followed a west-northwesterly course for the next three days which
  paralleled the southern Mexican coastline.  Peak intensity of 120 kts 
  (with an estimated central pressure of 945 mb) was attained at 25/0600
  GMT when the hurricane was centered about 275 nm south-southwest of 
  Manzanillo.  Hurricane Blas passed about 75 nm south of Socorro Island
  around 0900 GMT on 26 Jun.   About this time the storm turned to more
  of a westerly course which it followed throughout the remainder of its
  life.

     The hurricane was already weakening on 26 Jun and by the 27th was
  approaching sea surface temperatures of 24 C.   However, the cyclone's
  track was approximately parallel to the isotherms so Blas weakened
  quite slowly.   This slow weakening trend was also due in part to the
  fact that Blas had been a very intense hurricane with a well-defined
  vigorous circulation and did not encounter any significant vertical
  shear as it moved westward into cooler waters.   Most of the deep
  convection was gone by 28 June; however, an eye briefly re-appeared
  that day in a small area of cold convective tops.

     The weakening Blas was downgraded to a tropical storm at 28/1800
  GMT and to a depression at 0000 GMT on the 30th.   By 1200 GMT only
  a swirl of low clouds remained and the last advisory was issued,
  placing the center about 1200 nm west-southwest of Cabo San Lucas or
  approximately 1400 nm east of Hilo, Hawaii.   The weak remnants of
  Blas continued moving westward for several days, passing south of
  Hawaii during the first week of July, but did not show significant
  signs of re-intensification.

     Although Hurricane Blas did not directly strike any populated
  areas, the author did locate one report of some fatalities attributed
  to the storm.    A landslide due to heavy rains spawned by Blas
  was responsible for 4 deaths near El Chaparro in western Michoacan
  state, Mexico.
     
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  NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180

  Activity for June:  No tropical cyclones

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

  Activity for June:  1 tropical cyclone of hurricane intensity


                    Tropical Cyclone 03A   4-9 June
                    -------------------------------

     The most intense tropical cyclone seen in the Arabian Sea in at
  least the last 15 years was responsible for the deaths of over 1000
  persons, perhaps many more, in the coastal sections of northwestern
  India.   The first advisory on a new tropical depression, the second
  in the Arabian Sea within a week, was written by JTWC at 0000 GMT on
  4 June with the system centered slightly more than 450 nm south-
  southwest of Bombay, India.  Over the next 12 hours the depression
  meandered around in the Laccadive Islands and weakened as vertical
  shear increased.   Warnings were dropped at 04/1200 GMT, but were
  resumed 12 hours later when the shear appeared to have lessened and 
  convection was once more increasing around a tight low-level center.
  
     During this period the depression had remained quasi-stationary.
  After the 05/1200 GMT warning was issued, an amended warning was
  issued which re-located the center farther to the west and increased
  the maximum winds to 55 kts.  This was based on microwave and infrared 
  satellite imagery.   Well-defined banding features were noted at this
  time.   The intensifying cyclone began to move slowly to the northwest,
  later turning to a more northerly direction.   A ship report of 60-kt
  winds from near the center, along with a satellite-derived CI number
  of 4.0, led to the winds being increased to 70 kts in the warning
  issued at 06/0600 GMT.

     Tropical Cyclone 03A continued to increase in intensity as it
  moved northward in the Arabian Sea off the western coast of India.
  The cyclone passed about 300 nm west of Bombay around 0900 GMT on
  8 Jun shortly after reaching its estimated peak intensity of 100 kts.
  After crossing 20N the storm turned to the northeast and accelerated
  its forward motion.  The cyclone made landfall near Porbandar--roughly
  halfway between Bombay and Karachi, Pakistan--around 0300 GMT on 9 Jun
  with maximum sustained winds estimated near 90 kts.  The final JTWC
  advisory, issued at 09/1200 GMT, placed the center about 325 nm north-
  northwest of Bombay with 60-kt winds and rapidly weakening.

     The actual death toll from this cyclone may never be known with
  certainty.   The highest actual number seen by the author in various
  press reports was 1063 in Gujarat state, but comments by a relief
  worker indicated that between 10,000 and 14,000 persons had disappeared
  without a trace.     There were also 9 deaths reported in Rajasthan
  state and 12 fatalities in Pakistan, mostly from electrocutions,
  were attributed to the storm.

     Most of the casualties were salt workers or employees of the port
  at Kandla, about 300 nm northwest of Bombay.  Salt workers earn a
  living by trapping sea water in shallow farm fields where it evaporates
  in the fierce summer sun.    One report stated that although 20,000
  people from other villages on India's Arabian Sea coast were evacuated,
  officials said the forecast did not indicate the cyclone would hit
  the Kandla region (located near the head of the Gulf of Cutch).

     Press reports indicated that a storm surge of 16 ft (4.9 m) swept
  over the coastal regions where many of the salt workers were employed.
  Most of the workers were illiterate and too poor to own a radio, so
  they had no news of the impending cyclone.  Tragically, there was
  an allusion to a newspaper report which stated that contractors, eager
  to rake in profits, kept workers in the dark about the approaching
  storm.

     One press account indicated that port equipment (in Kandla) worth
  $4.7 million was destroyed and property damage in Gujarat state was
  estimated at $284 million.

  NOTE:  If anyone has any further details on the effects of this
  cyclone and will pass them along to me, I will include them as an
  update in next month's summary.

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

  Activity for June:  No tropical cyclones

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

  Activity for June:  No tropical cyclones

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

  Activity for June:  No tropical cyclones

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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:   jun98.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 June summary is the ninth 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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