Tropical Cyclones [Index]

Monthly Global Tropical Cyclone Summary December 1997 [Summaries and Track Data] [Prepared by Gary Padgett]

                  MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY

                              DECEMBER, 1997

    This summary should be considered a very preliminary overview of the
  tropical cyclones that occur in each month.   The cyclone tracks (that
  will be 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
           December as an example:   dec97.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.

    If anyone did not receive the October and/or November summaries
  and would like a copy, please e-mail me a request and I'll be happy 
  to forward a copy to them.

    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.

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

  ***********************************************************************

                           DECEMBER HIGHLIGHTS

 --> Long-lived supertyphoon devastates Guam
 --> Southern Cook Islands affected by cyclone
 --> Coast-hugging cyclone brings flooding to northern Australia

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                          ACTIVITY BY BASINS

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

  Activity for December:  No tropical cyclones

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

  Activity for December:  1 tropical storm


              Tropical Storm Paka (TC-05C)   2-7 December
              -------------------------------------------

     Tropical cyclones forming outside the nominal June to November
  hurricane season are very rare in the Northeast Pacific Basin.  In
  December, 1983, Hurricane Winnie formed just off the coast of
  southern Mexico.  In 1957 Hurricane Nina formed in the Central
  Pacific area in late November and continued into the early days 
  of December.  Nina brought hurricane force gusts to some of the
  Hawaiian Islands.  In 1992 Hurricane Ekeka (January) and Tropical 
  Storm Hali (March) were out-of-season storms.

     A weak tropical disturbance which had existed since late Nov had
  become sufficiently organized that depression advisories on Tropical
  Depression 05-C were begun at 1200 UTC on 2 Dec when the system was
  located about 600 nm south-southeast of Johnston Atoll.  This was
  the beginning of what was to become mighty Supertyphoon Paka west
  of the dateline almost two weeks later.  Tropical Storm/Supertyphoon
  Oliwa in Sep was the first Central Pacific-spawned storm to become
  a supertyphoon west of the dateline since Hurricane Sarah in Sep,
  1967--Paka repeated the feat three months later.    For this to
  happen twice in one season is surely an exceedingly rare event--the
  author is not aware of the last year in which this occurred.

     The depression had become Tropical Storm Paka by 1800 UTC on
  2 Dec and moved very slowly on a westerly to west-northwesterly track
  at a very low latitude for the next several days.  Paka passed about
  450 nm south of Johnston Atoll around 0900 UTC on 4 Dec with 45-kt
  winds.  In its early stages Paka presented a nice, circular appearance
  in satellite imagery, indicating that very little upper-level shear was
  affecting it.  The storm intensified up to 55 kts on the 4th, but began
  to slowly weaken as it continued westward.  By the time Paka had
  reached the 180th meridian at 0000 UTC on 7 Dec at a position about
  775 nm southwest of Johnston, it was only a minimal tropical storm.

     Warning responsibility was passed to the Joint Typhoon Warning
  Center on Guam when Paka crossed the dateline.  A description of the
  remainder of Paka's long history can be found in the section of this
  summary covering the Northwest Pacific Basin.

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

  Activity for December:  1 supertyphoon


               Supertyphoon Paka (TC-05C)   2-23 December
               ------------------------------------------

     Supertyphoon Paka had begun in the Central Pacific on 2 Dec hundreds
  of miles to the southwest of Hawaii.   The early history of Paka is
  described in the section of this summary covering the Northeast Pacific
  Basin.  As a minimal tropical storm Paka crossed the dateline at 8.4N
  around 0000 UTC on 7 Dec.  The storm initially strengthened during the
  day but weakened slightly on the 8th.  By early on the 10th Paka was
  beginning to intensify once more.   The strengthening tropical storm
  passed about 20 nm south of Majuro in the Marshall Islands during the
  afternoon of 10 Dec (local time) with maximum sustained winds estimated
  at 50-55 kts.   Typhoon intensity was attained at 1800 UTC when passing
  about 50 nm north of Jaluit Atoll.  Paka had moved on a course tending
  toward the west-southwest after crossing the 180th meridian, and was
  located at the unusually low latitude of 6.9N when upgraded to a
  typhoon.  After dropping as far south as latitude 6.7N, the typhoon
  began to move on a very gradual west-northwesterly course.

     Winds had climbed to 100 kts by 11/1200 UTC when the typhoon was
  centered about 125 nm south-southeast of Kwajalein.  Doppler radar from
  Kwajalein helped to confirm the position of the storm as it passed by
  the island.  Typhoon Paka continued to intensify through the 12th as
  winds reached 115 kts by 0600 UTC, but then a slight weakening of the
  storm was observed.  By the time Paka was passing 150 nm south of
  Eniwetok at around 0600 UTC on 13 Dec, maximum winds had dropped to
  95 kts.  After this, however, a steady strengthening trend began.  The
  typhoon passed about 200 nm north of Pohnpei at 13/2100 UTC with
  115-kt winds.  Paka was by this time moving more to the west-northwest,
  and its forward motion increased some on the 14th.     Supertyphoon
  intensity was initially reached at 0000 UTC on 15 Dec about 300 nm
  north-northwest of Truk.

     Paka's estimated maximum sustained winds peaked at 140 kts, then
  began to decrease slightly as the storm approached the Marianas.  The
  JTWC warnings reported the storm's intensity at 125 kts as the eye
  passed just off the northern tip of Guam at around 1200 UTC (2200
  local) on 16 Dec.  The JTWC warning at 16/0000 UTC mentioned a Doppler
  radar wind estimate of 117 kts, and a mesocyclone was noted rotating
  in the eyewall.   The 16/0600 UTC warning reported Doppler estimates
  as high as 134 kts.   At this time the center of the eye of Typhoon
  Paka was located 25 nm south of the eastern point of Rota. 

     After passing through the Marianas Paka continued on a westerly to
  west-northwesterly course which took it into the Philippine Sea.  Peak
  intensity of 160 kts occurred at 0000 UTC on 18 Dec when the center
  was located about 300 nm west of Guam.  A rather steady decline in
  intensity took place afterward as the storm began to encounter rather
  significant upper-level shear.  Winds had dropped below supertyphoon
  levels by 19/0000 UTC, and Paka was downgraded to a tropical storm
  two days later.   By 1800 UTC on 21 Dec JTWC issued the last warning,
  downgrading the system to a weakening depression about 800 nm west-
  northwest of Guam.  The Japanese Meteorological Service mentioned the
  dissipating depression in their high seas forecasts for another day or
  so.

     Press reports indicated that all of Guam's 135,000 residents
  lost electrical power, 70% were without water, and 8000 telephone
  subscribers were without service.   Seventeen typhoon-related injuries
  were reported, including a Japanese tourist who suffered a fractured
  skull after being hit by flying debris and a woman whose fingers were
  amputated when a wind-blown car door slammed on her hand.

     The staff of JTWC has prepared an excellent report on Supertyphoon
  Paka.  It can be accessed on JTWC's website at:

     http://www.npmocw.navy.mil/npmocw/prods/paka.html

  This report is very informative, and especially interesting is the
  detailed analysis of how the maximum winds experienced on Guam were
  determined.   The maximum sustained winds (1-min) have been estimated
  at 130 kts with peak gusts of 160 kts.  This makes Paka more intense
  than Typhoons Pamela (1976) and Omar (1992), but not as intense as
  Typhoon Karen of November, 1962, which struck Guam with sustained
  winds of 135 kts and gusts to 165 kts.  The widely reported peak gust
  in Paka of 205 kts is not considered representative of the winds that
  were actually occurring in the storm.    Destruction of private and
  commercial buildings, infrastructure, crops, and vegetation was
  extensive, and damage estimates run into the hundreds of millions
  of dollars.  The report mentions that serious damage was incurred on
  the island of Rota, but no particulars are given.  Very fortunately
  though, and perhaps remarkably, no lives were lost due to Typhoon Paka.
  
     The information on winds presented above was taken from the
  aforementioned report on JTWC's website.  I highly recommend it to
  anyone who is interested in learning more about Typhoon Paka's
  destructive strike on Guam.

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

  Activity for December:  No tropical cyclones

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

  Activity for December:  No tropical cyclones

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

  Activity for December:  1 tropical cyclone of storm intensity
                          1 tropical cyclone of hurricane intensity

  NOTE:  Much of the information below was obtained from the cyclone
         summary portion of the Darwin Tropical Diagnostic Statement
         for December, 1997.  This was sent to me by Peter Bate of
         the Darwin TCWC.  A special thanks to Peter for supplying
         me with this material.


             Tropical Cyclone Sid (TC-08S)   26-28 December
             ----------------------------------------------

     A low pressure system formed over the northwestern corner of
  Australia's Northern Territory in late Dec and moved into the Timor
  Sea as the monsoon trough developed near Australia.  A tropical
  depression had developed by 26/0000 UTC about 75 nm north-northeast
  of Darwin.  The system had reached gale force six hours later and
  was christened Sid by the Darwin TCWC.  Tropical Cyclone Sid moved
  eastward, hugging the coast of the Northern Territory.  At 0500 UTC
  on 26 Dec McCluer Island reported sustained winds of 35 kts.  Sid
  began curving southeastward and crossed over the northeast corner
  of the Northern Territory, passing near the town of Nhulunbuy. The
  cyclone then passed just off the northeast corner of Groote Eylandt,
  where gusts to hurricane force were experienced.  Sid then moved on
  a southerly course toward the lower Gulf of Carpentaria where it
  weakened due to restricted outflow and upper-level shear.

     By 1200 UTC on 28 Dec Sid had weakened to less than gale force in
  the southern Gulf about 30 nm west of Wellesley Island.  The center
  crossed the coast, and the residual LOW meandered around the Northern
  Territory for several days, eventually moving back out over the Gulf
  of Carpentaria.  Warnings were resumed for a couple of days in early
  January since there was a chance the depression might re-intensify.
  (A little more information on the system will be included in the
  summary for January.)

     The author has received no reports of damage or casualties from
  Tropical Cyclone Sid.   Heavy rains reportedly caused flooding in
  low-lying areas near the Gulf of Carpentaria.


       Tropical Cyclone Selwyn (TC-09S)   26 December-2 January
       --------------------------------------------------------

     A tropical LOW formed in the monsoon trough soon after Sid had
  developed to the east-northeast during the first active phase of the
  north Australian westerly monsoon season.  At 1800 UTC on 26 Dec
  the developing system was a depression with 30-kt winds located about
  650 nm west-northwest of Broome, Western Australia.  Tropical Cyclone
  Selwyn was named about 12 hrs later moving on a west-southwesterly
  course.  Upper-level outflow initially favored intensification and
  Selwyn reached hurricane force by the 28th.  However, an upper trough
  approached from the west, and the resultant vertical shear, combined
  with entrainment of drier air, caused Selwyn to begin to weaken.

     The west-southwesterly motion had carried the cyclone to a position
  almost 1000 nm west of Broome by 29/1200 UTC.  After this Selwyn began
  to weaken fairly rapidly and the center began to move slowly to the
  west-northwest.  Warnings were discontinued by the Perth TCWC at 0000
  UTC on 31 Dec with winds forecast to drop below gale force over the
  next 24 hrs.  The residual LOW drifted westward and then southwestward
  over the next several days with convection occasionally flaring up.
  Warnings were re-initiated for a brief period in early January when
  the system was forecast to re-intensify, but this failed to happen.
  Satellite classifications continued for a couple of days, tracking the
  dissipating system southwestward to near 20S, 86E by 1800 UTC on 3 Jan.

  (Since only two warnings on this system were issued by Perth on 1 and
  2 Jan, this will not be included in the January summary.   The track 
  file for December will show the complete history of Selwyn.)

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

  Activity for December:  1 tropical cyclone of storm intensity **

  NOTE: A special thanks to Steve Ready of the New Zealand Meteorological
        Service for forwarding to me a report from Arona Ngari, Manager
        of the Cook Islands Meteorological Service, relating the effects
        of Pam's close brush with the island of Rarotonga in the southern
        Cooks.  A special thanks also to Mark Kersemakers of the Fiji
        TCWC at Nadi for sending me the track and intensity information
        for Tropical Cyclone Pam.

    ** - operationally classified as a hurricane by Fiji and JTWC


           Tropical Cyclone Pam (TC-07P)   5-10 December
           ---------------------------------------------

     The Fiji TCWC at Nadi issued the first warning on a developing
  depression at 0000 UTC on 5 Dec.  The system was then centered about
  425 nm northeast of American Samoa and about 1150 nm southeast of
  Tropical Storm Paka in the Central North Pacific.  Paka and Pam
  were cyclone twins, forming in opposite hemispheres, whose development
  was related to an equatorial westerly wind burst.  Such cyclone pairs
  are often seen during El Nino events when the SOI index is experiencing
  a negative phase.  The system developed slowly as it drifted to the
  south-southeast.  By 1800 UTC on the 5th the depression was located
  250 nm west of Manihiki Atoll in the northern Cooks with 30-kt winds.

     Maximum sustained winds (10-min avg) had increased to gale force
  by 06/1200 UTC.  At this time the separation between Pam and Paka
  had increased to 1500 nm as Paka was approaching the dateline.  Pam
  passed very near Suwarrow Atoll around 1800 UTC and was beginning
  to move a little faster on a southerly course.  The AWS on Aitutaki
  Atoll reported winds of 33 kts at 07/1800 UTC.   At this time the
  center of Pam was about 200 nm west-northwest of the atoll.  At 08/0000
  UTC the cyclone passed about 75 nm east of Palmerston Island with 55-kt
  winds.    Pam was located about 100 nm north-northwest of Rarotonga
  at 08/1200 UTC with maximum sustained winds estimated at 60 kts. (The
  real-time warnings were carrying Pam as a hurricane at this point, but
  in post-analysis it was determined that the storm was probably just
  under hurricane force.)

     Pam passed about 40 nm southwest of Rarotonga at 0600 UTC on 9 Dec.
  By this time the storm was beginning to weaken as it turned to more of
  a southeasterly course.  Rarotonga reported maximum sustained winds of
  39 kts with peak gusts to 64 knots.  Strangely, the lowest pressure of
  986 mb wasn't recorded until 10/0600 UTC, after the storm had moved on
  to the southeast.  Instead of the usual sudden drop in pressure, the
  barograph trace recorded a gradual decrease for 12 hrs followed then
  by a gradual increase over the next 12 hrs.  (Possibly Pam was already
  becoming extratropical at this time.  Satellite images revealed that 
  the system had more of a hook shape rather than an enclosed eyewall.)
  
     The weakening cyclone passed about 80 nm southwest of Mangaia around
  1200 UTC on 9 Dec.  Mangaia reported sustained winds of 26 kts and a
  pressure of 996 mb, but the pressure is considered suspect.  By 0000
  UTC on 10 Dec Pam was located about 100 nm south-southeast of Mangaia,
  and was rapidly weakening and losing its tropical characteristics. The
  last advisory from Nadi downgraded the system to a depression with
  30-kt winds at 1200 UTC on the 10th.

     Damage on Rarotonga seems to have been light--mainly consisting of
  fallen trees and power lines.  A few houses lost their roofs.  There
  was some flooding of low-lying roads due to both heavy seas and rain.
  During the passage of Pam 149 mm of rainfall was recorded in a 6-hr
  period.  No reports of casualties due to Tropical Cyclone Pam have
  been received by the author.

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