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


                             SEPTEMBER, 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.)


                            2000 - 2001 SEASON

     The Australian Bureau of Meteorology maintains three Tropical
  Cyclone Warning Centres (TCWC):  Perth, Western Australia; Darwin,
  Northern Territory; and Brisbane, Queensland.  Each centre is allotted
  a separate list of tropical cyclone names for tropical cyclones forming
  within its area of responsibility (AOR).  In addition a TCWC located at
  Port Moresby, Papua New Guinea (PNG)--a former Australian territory--
  maintains a list of native names to assign to the very rare tropical
  cyclones which form within its AOR.

     The AORs of the respective centres are:

  (1) Perth - 125E westward to 90E.  Technically, Perth's AOR is south of
      10S with Indonesia being responsible for waters north of 10S, but
      I believe the plan is that any rare tropical cyclone which might
      form north of 10S would be named by Perth.

  (2) Darwin - 125E eastward to 138E and extending northward to the
      equator.  There is a little irregularity with the eastern border
      in the Gulf of Carpentaria.  The Darwin TCWC issues High Seas
      Warnings for the entire Gulf of Carpentaria, but Brisbane issues
      Tropical Cyclone Advices and names cyclones in the eastern portion
      of the Gulf.

  (3) Brisbane - 138E eastward to 160E and generally south of 10S.  The
      northern border with the Port Moresby AOR is somewhat irregular.

  (4) Port Moresby, PNG - immediate vicinity of the island of New Guinea
      and eastward to 160E generally north of 10S although the southern
      border is somewhat irregular.

     Names for the 2000-2001 season (** indicates name has already been

          Perth          Darwin        Brisbane        Port Moresby

         Sam **         Winsome         Wylva            Epi
         Terri **       Alistair        Abigail          Guba
         Vincent        Bonnie          Bernie           Ila
         Walter         Craig           Claudia          Kama
         Alex           Debbie          Des              Matere
         Bessi          Evan            Erica            Rowe
         Chris          Fay             Fritz            Tako
         Dianne         George          Grace            Upia
         Errol                          Harvey
         Fiona                          Ingrid
         Graham                         Jim
         Harriet                        Kate
         Inigo                          Larry
         Jana                           Monica
         Ken                            Nelson

                      and the SOUTH PACIFIC OCEAN

     The Tropical Cyclone Warning Centre (TCWC) at Nadi, Fiji, has
  tropical cyclone warning responsibility for the South Pacific east of
  160E and from the equator to 25S.   The Meteorological Service of New
  Zealand at Wellington has warning responsibility for waters south of
  25S, but almost all tropical cyclones in this basin form north of 25S.
  When a rare cyclone forms in the Wellington area of responsibility
  (AOR), it usually will be assigned a name from the Fiji list (such as
  was done for Tropical Cyclone Gita in February, 1999.)

     Tropical cyclone warning responsibility for South Indian waters west
  of 90E are shared by several TCWCs.       The Regional Specialty
  Meteorological Centre (RSMC) for the region is the office of Meteo
  France on the island of La Reunion.  However, following a long-standing
  practice, the sub-regional centres at Mauritius and Madagascar share
  the responsibility for actually naming tropical storms with Mauritius
  naming systems east of 55E and Madagascar covering the area west of
  55E.   RSMC La Reunion issues warnings for the basin independently of
  these sub-regional centres, but only advises regarding when or when not
  to assign a name to a developing cyclone.  (I included the Southwest
  Indian names in the August summary but am repeating them here for

     Names for the 2000-2001 season (** indicates name has already been

       Southwest Indian                          South Pacific

     Ando **           Nancy                 Oma           Beni
     Bindu **          Oda                   Paula         Cilla
     Charly **         Premnath              Rita          Dovi
     Dera              Quirin                Sose          Eseta
     Evariste          Rakoto                Trina         Fili
     Francois          Suzy                  Vicky         Gina
     Gaby              Tovo                  Waka          Heta
     Hans              Ursula                Yolande       Ivy
     Idriss            Vimla                 Zoe           Judy
     Jakoba            Wenda                 Ami           Kerry
     Kiran             Xino
     Lanto             Yul
     Mathieu           Zoe


                         SEPTEMBER HIGHLIGHTS
  --> Atlantic basin very active with seven named storms
  --> Active Northwest Pacific basin features two super typhoons


               ***** Topic of the Month for September *****


     For the Topic of the Month feature in the July summary I presented
  some seasonal statistics for the Eastern North Pacific compiled by
  John Wallace of San Antonio, Texas.   This month I am including a
  similar table for the Central North Pacific--that region of the North
  Pacific lying between longitudes 180 and 140W.  I prefer to consider
  the entire North Pacific east of the Dateline as one basin (Northeast
  Pacific), but due to the fact that warnings are handled by two
  different agencies (TPC/NHC in Miami and CPHC in Honolulu), the areas
  east and west of 140W are often considered separately.

     A full description of the seven parameters in the table below would
  needlessly lengthen this article.  Definitions can be found on the
  Colorado State University Tropical Meteorology site:

     I will, however, simply explain the abbreviations:

  NS:   Named Storms (includes unnamed storms added in post-analysis)
  H:    Hurricanes
  IH:   Intense Hurricanes
  NSD:  Named Storm Days
  HD:   Hurricane Days
  IHD:  Intense Hurricane Days
  NTC:  Net Tropical Cyclone Activity (%)

     The statistics given in the following table are based upon all
  tropical cyclones of tropical storm intensity or higher which either
  formed in or moved through the Central North Pacific.  The various
  "days" parameters include only the period in which the cyclone was
  located between longitudes 180 and 140W.  Three storms which formed
  west of the Dateline and moved eastward into the Central North Pacific
  are not included due to their omission from the Northeast Pacific
  Best Track file.  These storms are: Virginia (1968), Carmen (1980),
  and Skip (1985).     The latter two actually formed as tropical
  depressions in the Central Pacific, moved westward across the Dateline
  and were named by JTWC, then recurved eastward and existed briefly
  as tropical cyclones east of longitude 180.  However, for Hurricane
  John of 1994, the time spent east of the Dateline after it had recurved
  and moved northeastward is included in the NSD and HD parameters.

                  Central North Pacific Seasonal Parameters

                             1966 - 1999

  YEAR    NS      H     IH      NSD      HD      IHD     NTC

  1966     3      1      0      8.75     2.25     .00     54
  1967     3      1      0     11.00      .50     .00     51
  1968     0      0      0       .00      .00     .00      0
  1969     0      0      0       .00      .00     .00      0
  1970     2      1      0      5.50      .50     .00     36
  1971     2      1      0      3.25     1.75     .00     37
  1972     5      1      1     20.75     9.00    1.75    170
  1973     2      1      1     10.50     4.50     .25     92
  1974     2      1      1      4.50     3.50     .25     77
  1975     1      1      0      3.00      .75     .00     26
  1976     1      1      0      8.75     4.75     .00     53
  1977     0      0      0       .00      .00     .00      0
  1978     6      4      2     30.00    16.25    2.75    301
  1979     0      0      0       .00      .00     .00      0
  1980     1      1      0      4.50     2.75     .00     37
  1981     2      0      0      3.00      .00     .00     17
  1982    10      5      1     30.25     6.50    1.50    252
  1983     4      1      1     12.00     1.50    1.25    110
  1984     4      1      1     10.25     2.75     .25     96
  1985     5      4      2     18.25    12.75    2.75    260
  1986     2      2      1      6.50     4.25    1.50    116
  1987     4      1      0     12.50     4.25     .00     75
  1988     4      2      2     14.25    10.75    4.25    238
  1989     1      1      0      4.50     2.50     .00     36
  1990     3      1      1     10.75     2.75    2.25    123
  1991     2      2      0      4.50     1.50     .00     50
  1992     7      2      2     16.25     8.50    2.50    223
  1993     3      2      1     13.25     8.50    1.50    151
  1994     8      5      3     34.00    18.50   12.75    527
  1995     0      0      0       .00      .00     .00      0
  1996     0      0      0       .00      .00     .00      0
  1997     4      0      0     11.50      .00     .00     44
  1998     1      1      0      2.00      .25     .00     22
  1999     2      2      1      9.00     7.25     .25    112

  Avg.    2.8    1.4    0.6     9.5      4.1     1.1     100

     In terms of NTC the year 1994 stands head-and-shoulders above all
  other years.   It is not the year with the highest number of named
  storms and ties 1982 for the highest number of hurricanes, but in
  terms of HD and IHD it ranks far above all other years.  All three
  of the intense hurricanes that prowled the waters of the Central
  Pacific that summer were Category 5 hurricanes on the Saffir/Simpson
  scale--Emilia, Gilma, and John.   Hurricane John lasted 31 days and
  holds the record as the world's longest-lived tropical cyclone.  John
  is also the only tropical cyclone on record to travel from the Eastern
  North Pacific across the Central North Pacific and enter the Western
  North Pacific, and then move back eastward and re-enter the Central
  North Pacific.

     A majority of the tropical cyclones in the Central North Pacific
  are visitors from east of 140W.      Of the 98 tropical storms or
  hurricanes in the region from 1966-2000 (there were four Central
  Pacific storms in 2000), 32 actually formed between 140W and the
  Dateline.  Those storms are listed below (an asterisk following the
  name indicates that the cyclone moved across longitude 180 into the
  Northwest Pacific basin):

  1967 - Sarah *                    1985 - Nele
  1970 - Dot                        1987 - Oka, Peke *
  1972 - June, Ruby *               1988 - Uleki *, Wila
  1974 - Olive                      1990 - Aka *
  1975 - unnamed                    1992 - Ekeka *, Hali, Iniki
  1976 - Kate                       1993 - Keoni *
  1978 - Susan                      1994 - Li *, Mele, Nona
  1982 - Akoni, Ema, Hana, Iwa      1997 - Oliwa *, Paka *
  1984 - Keli, Lala, Moke           2000 - Upana ++, Wene &&

  ++ - Upana weakened and warnings were dropped by CPHC, but the remnant
       LOW moved into the NWP basin, redeveloped, and was named Chanchu
       by JMA

  && - Wene actually formed as a tropical depression just west of the
       Dateline, moved northeastward, and reached tropical storm
       intensity near 179W

                           ACTIVITY BY BASINS

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

  Activity for September:  1 tropical depression
                           2 tropical storms
                           5 hurricanes

  NOTE:  Much of the information presented below was obtained from the
  TPC/NHC discussion bulletins issued with every regular advisory.  All
  references to sustained winds imply a 1-min averaging period unless
  otherwise noted. 

                  Atlantic Tropical Activity for September

     After getting off to a slow start, the month of September became
  very active in the latter half.  Seven named tropical cyclones formed,
  plus one short-lived tropical depression.   The only other two years
  on record in which seven storms formed in September are 1949 and 1988.
  Also, five of the cyclones reached hurricane intensity--above normal,
  but not all that uncommon--five hurricanes formed in September, 1998.
  Two storms, Gordon and Helene, made landfall along the Gulf Coast of
  the U. S. as tropical storms.    Hurricane Keith formed at the end of
  the month in the northwestern Caribbean and quickly intensified into
  a Category 4 hurricane on the Saffir/Simpson scale just off the coast
  of the southern Yucatan Peninsula.   After stalling just offshore, the
  hurricane weakened and made landfall near the Belize/Mexico border as
  a strong tropical storm.    Keith later re-intensified in the Bay of 
  Campeche and made a final landfall in eastern Mexico north of Tampico 
  as a strong Category 1 hurricane.    Hurricanes Florence, Isaac, and 
  Joyce as well as weak Tropical Storm Ernesto all remained at sea.

     A short-lived and generally weak tropical depression formed in the
  northwestern Gulf of Mexico on 8 September and moved inland the next
  day near the mouth of the Sabine River which forms the boundary between
  Louisiana and Texas.     The depression was spawned by the interaction
  between a low-level trough which had persisted over the Gulf and a
  convective cluster associated with a tropical wave.  Squalls with gusts
  to tropical storm force occurred well to the east of the center at some
  buoys and a C-MAN station near Southwest Pass.   More information on
  this system can be found in the official report authored by Jack Beven
  on TPC/NHC's website:> .

     The official TPC/NHC tropical cyclone reports prepared by the
  Hurricane Specialists are now available for most of the 2000 Atlantic
  basin tropical cyclones.   The reports are very interesting and
  informative, and links to them can be found at the following URL:> .   Since I am running so far
  behind schedule, and since I think it highly likely that just about
  every person who reads these summaries has access to the internet, I
  am going to trim down the amount of material I write about the
  remaining Atlantic cyclones--primarily including a few items of
  interest which are not mentioned in the official NHC reports.

                     Tropical Storm Ernesto  (TC-08)
                            2 - 3 September

     The first mention of the tropical wave which ultimately developed
  into Tropical Storm Ernesto was in a Tropical Weather Outlook issued
  by TPC/NHC early on 29 August.   A tropical wave was passing south of
  the Cape Verde Islands.   Whether or not this was the same wave which
  moved off the coast of Africa on 27 August or a second wave on its 
  heels isn't completely clear.   A 1010-mb LOW was noted on the wave
  axis at 1800 UTC, and the Tropical Weather Outlook at 2230 UTC on the
  30th indicated that convection had become better organized.  At the
  time upper-level winds in the region a few hundred miles west of the
  Cape Verdes were favorable for continued development, but became less
  favorable later as the system moved farther to the west.   The wave
  was given a poor chance for development on 31 August due to hostile
  winds aloft, but at 0900 UTC on 1 September a Special Tropical
  Disturbance Statement was issued which indicated that strong thunder-
  storms had developed overnight near the center of circulation and that
  a depression could possibly form during the day if the convection
  persisted near the LLCC.     However, the system was moving west-
  northwestward at 17-22 kts and this rapid translational speed was
  judged to be an inhibiting factor for significant strengthening.

     The system remained well-organized and by the afternoon of the 1st
  it appeared that a depression might be forming.    Advisories were
  initiated on TD-08 at 0300 UTC on 2 September with the poorly-defined
  center estimated to be about 750 nm east of the island of Martinique.
  The depression was moving slightly north of due west at about 12 kts.
  Deep convection increased significantly overnight near the LLCC and
  TAFB assigned a Dvorak rating of T2.5 at 0600 UTC.    This, in
  conjunction with some 30-kt wind reports from a buoy well north of
  the center, was the basis for upgrading the depression to Tropical
  Storm Ernesto at 0900 UTC.   Outflow had improved somewhat to the
  north, but the cyclone was still experiencing the effects of southerly

     Ernesto never intensified beyond minimal tropical storm intensity.
  The hostile upper-level environment over the eastern Caribbean which
  had sheared Chris and Debby persisted for two or three weeks and
  Ernesto became its next victim.  Such a highly unfavorable pattern
  during the peak of the hurricane season is rather unusual, especially
  in a year which was overall quite active.   Had this feature not been
  present, and Chris, Debby and Ernesto been allowed to have developed
  into well-organized hurricanes, things could have been very different
  for the U. S. East Coast.   Satellite images around 0000 UTC on the 3rd
  revealed that the LLCC was located on the edge of the deep convection
  but close enough to justify keeping Ernesto as a tropical storm.  In
  addition a QuikScat pass at 02/2200 UTC showed several places with
  tropical storm-force winds to the north of the center.

     The weak tropical storm continued to move to the west-northwest
  at about 15 kts on 3 September, and the large upper-tropospheric trough
  situated about 15 degrees to the west continued to create strong south-
  southwesterly shear over the cyclone.  During the afternoon the cloud
  pattern began to deteriorate rapidly and low-level cloud motions
  indicated that a closed circulation no longer existed, so Ernesto was
  downgraded to a tropical wave at 2100 UTC.  The final advisory position
  was roughly 300 nm northeast of Guadeloupe.  Interestingly, as was the
  case with Debby, some of the numerical models had forecast that Ernesto
  would strengthen in spite of the shearing environment.  And again, as
  with Debby, this failed to materialize.

  NOTE:  The official report on Tropical Storm Ernesto, authored by
  Miles Lawrence, is now available on TPC/NHC's website at the following
  URL:> .

                       Hurricane Florence  (TC-10)
                             11 - 18 September

     Hurricane Florence was a Category 1 hurricane on the Saffir/Simpson
  scale which formed in the subtropics and later brushed the island of
  Bermuda as it accelerated to the northeast.  The official storm report
  on Florence, prepared by James Franklin, can be found at the following
  URL:>.   I recommend that
  interested readers first connect to TPC/NHC's website and read James'
  report, which contains a tabular listing and plot of the analyzed
  "best track" as well as plots of meteorological information.

     Florence serves as a good illustration of the revisions to the
  operational track and (especially) intensities that are often made
  during the post-storm analysis process.   The "best track" indicates
  that Florence had reached tropical storm intensity by 1200 UTC on
  11 September--this based on a QuikScat pass.   The 1030 UTC Tropical
  Weather Outlook still referred to the system as a non-tropical LOW but
  indicated that convection was becoming better organized and that there
  was a potential for tropical cyclone development over the next few
  days.  The first advisory on the LOW was issued at 11/1500 UTC,
  classifying the system as Tropical Depression Ten.    The discussion
  bulletin mentioned the earlier QuikScat pass and indicated that a
  reconnaissance aircraft was on the way to investigate the system.

     A special advisory was issued at 1800 UTC, upgrading Florence to
  a 50-kt tropical storm.  This was based on a reconnaissance report of
  winds to 64 kts at 300 m in convection southeast of the center.  While
  the "best track" indicates that Florence reached hurricane intensity
  for a brief period at 1800 UTC, it should be pointed out that in real-
  time the storm was not upgraded to a hurricane until 2100 UTC on the
  12th.    The discussion bulletin issued along with the 11/2100 UTC
  advisory contains a good example of the sort of decisions the
  forecaster often has to make on the spot, some of which (as in this
  case) are later revised after a thorough analysis of all the data.
  I quote from Discussion Number 3 (5 PM EDT Mon, Sep 11 2000), written
  in fact by James Franklin: "We are reminded once again that there is no
  substitute for aircraft reconnaissance observations.  While the Dvorak
  satellite technique estimated an intensity of 35 kts, the recon found a
  large area of winds at the 1000 ft level in excess of 60 kts, and even
  a small area of winds in excess of 75 kts on the edge of the
  convection.  This supports surface winds of 60 to 65 kts.  I would like
  to see these winds persist a bit before making Florence a hurricane."

     Since the convection soon began to wane, the decision was made not
  to upgrade Florence to a hurricane at the time, but in post-analysis it
  was apparently felt that the observations from the reconnaissance plane
  justified upgrading the storm to minimal hurricane status for a 12-hour
  period.   Eric Blake, who wrote a summary for me of Hurricane Alberto,
  researched the "best track" database and concluded that Alberto was the
  first known Atlantic hurricane to have reached hurricane intensity
  three separate times during its history.   Remarkably, the same thing
  happened again just a month later with Hurricane Florence.

     Florence later passed only 65 nm to the northwest of Bermuda but had
  no significant effects on the island.  There were three drownings along
  the coast of North Carolina due to rip currents likely related to the
  storm.  In its later stages Florence was headed for the Cape Race,
  Newfoundland, area but was absorbed by a large extratropical LOW while
  still to the south of the island.   The peak intensity of 70 kts was
  reached on 16 September when Florence was located about 275 nm north-
  east of Bermuda.

                        Hurricane Gordon  (TC-11)
                             14 - 19 September

     Hurricane Gordon was a Category 1 hurricane on the Saffir/Simpson
  scale which formed in the northwestern Caribbean Sea near the Yucatan
  Peninsula, reached hurricane intensity in the southeastern Gulf of
  Mexico, and later weakened to a tropical storm before making landfall
  in the Big Bend area of northwestern Florida.     The official storm
  report on Gordon, prepared by Stacy Stewart, can be found at the
  following URL:>.  I recommend
  that interested readers first connect to TPC/NHC's website and read
  Stacy's report, which contains a tabular listing and plot of the
  analyzed "best track" as well as plots of meteorological information.

     As the official report points out, Gordon developed from a tropical
  wave which left the coast of western Africa on 4 September and traveled
  across the Atlantic and Caribbean.   This wave was somewhat interesting
  in its pre-depression stage in the northwestern Caribbean in that for
  a couple of days its appearance in satellite imagery was suggestive of
  a tropical depression, but reconnaissance flights on both 12 and 13
  September could find no evidence of a low-level circulation, although
  a well-defined mid-level circulation was quite apparent.  Finally on
  the 14th a reconnaissance plane was able to find a small circulation
  just off the Yucatan coast, so advisories were initiated on Tropical
  Depression Eleven at 1500 UTC.  

     Immediately after being upgraded to a depression, the system moved
  inland over the Yucatan Peninsula.  During the morning of 15 September
  the low-level center reached the north-central coast of Yucatan while
  the mid-level center and deeper convection were farther to the east.
  Richard Henning, a meteorologist at Eglin AFB and a member of the
  53rd Weather Reconnaissance Squadron, The Hurricane Hunters, was
  present on a flight into the depression on the evening of the 15th.
  Rich related to me that the low-level center, which had for much of
  the day been "wandering along the beach" to the west of the mid-level
  center, suddenly seemed to be "sucked into" the deeper convection to
  the east or northeast.   That flight found 59-kt winds at 450 m just
  east of the center, leading to Tropical Storm Gordon's being named at
  2100 UTC.

     Based on a ship report Gordon was upgraded to a hurricane in a
  special update issued at 2145 UTC on the 16th.  The storm reached its
  estimated peak intensity of 70 kts around 0600 UTC on 17 September.
  Operationally, the highest MSW assigned to Gordon was 65 kts, the
  slight increase of 5 kts being decided upon during post-storm analysis.
  There was another interesting aspect of Gordon which should be pointed
  out.  The peak flight-level wind found by a reconnaissance aircraft
  was 89 kts at 0544 UTC on 17 September.  The accompanying minimum
  CP found at that time was 992 mb.  A little over two hours later, at
  0805 UTC, the pressure had fallen 11 mb to 981 mb--the minimum for the
  storm--but the maximum flight-level wind found during that pass was
  only 80 kts.

     Gordon weakened to a 55-kt tropical storm before making landfall
  due to the combined effects of southwesterly shearing and entrainment
  of drier air into the circulation.  The center of the cyclone made
  landfall just northwest of Cedar Key, Florida, near the mouth of the
  somewhat-famous Suwanee River.   Damage from the storm was relatively
  light--mainly downed trees and power lines.  Some homes along the
  Florida west coast between Tampa Bay and Cedar Key had minor roof
  damage and some coastal roads were flooded.  The damage estimate for
  the U. S. is $10.8 million.     One death occurred when a surfer
  drowned in heavy seas near Pensacola, Florida, as Gordon was making
  landfall farther to the east.

     There were 23 deaths reported in Guatemala due to flooding from
  heavy rains in mountainous areas which may have been due in part to
  the depression and pre-depression stages of Gordon in the northwestern
  Caribbean and over Mexico's Yucatan Peninsula.

                      Tropical Storm Helene  (TC-12)
                             15 - 25 September

     Tropical Storm Helene was a fairly long-lived and much-traveled
  tropical cyclone which reached tropical storm intensity twice and
  made landfall along the Florida Panhandle coast near Fort Walton
  Beach.  The official storm report on Helene, co-authored by Eric
  Blake and Lixion Avila, can be found at the following URL:>.  The author recommends that
  interested readers first connect to TPC/NHC's website and read Eric's
  and Lixion's report, which contains a tabular listing and plot of the
  analyzed "best track" as well as plots of meteorological information.

     Like Florence, Helene serves as a good illustration of the revisions
  that may be made in the "best track" as compared with the real-time
  operational warnings.  The most notable change was the reclassification
  of the system as a tropical storm after it emerged back into the North
  Atlantic off the Virginia coast on 24 September.   No operational
  advisories were issued for this portion of Helene's life--the storm
  being carried operationally as a non-tropical system.    The global
  tropical cyclone tracks file for September, which I disseminated in
  late October, indicated that Helene had subtropical characteristics
  during this phase of its history.    This was based on the opinion of
  David Roth, a meteorologist at HPC who has extensively studied hybrid
  and subtropical systems.   During post-storm analysis it was decided
  to treat the system as a tropical storm even though its appearance was
  not exactly that of a classic tropical cyclone.  Reports from a ship,
  the Neptune Olivine, were extremely helpful in determining the
  intensity of Helene during its North Atlantic phase.   The analyzed
  "best track" reports a peak MSW of 60 kts at 25/0600 UTC--the same
  as the peak intensity attained by Helene while in the Gulf of Mexico.

     Helene developed from a tropical wave which left the African coast
  around 10 September.  The system was upgraded to Tropical Depression
  Twelve on 15 September about 500 nm east of the island of Guadeloupe.
  However, the next day the system appeared to be weakening and a
  reconnaissance flight discovered that there was no longer a closed
  low-level circulation, even though winds to 55 kts at 450 m were found
  north and east of the wave.   The residual wave continued to move west-
  ward through the Caribbean Sea, and on the afternoon of the 19th a
  NOAA plane found that the depression had regenerated in the north-
  western Caribbean near Grand Cayman and was moving west-northwestward.
  All conditions seemed to be on "go" for continued intensification of
  the regenerated TD-12, but the system remained very weak with minimal
  convection through the 20th.  It is possible that an area of convection
  in the southwestern Gulf of Mexico, which on 19 September seemed to
  be rapidly organizing, may have helped to inhibit the depression from
  strengthening further at the time.    By the 20th the outflow from
  Tropical Storm Norman in the Pacific was streaming across the Bay of
  Campeche and the disturbance in that area weakened.

     TD-12 moved into the southeastern Gulf of Mexico late on the 20th,
  and by the early morning of 21 September the satellite signature had
  improved with deep convection forming near the center and enhanced
  outflow evident.     Buoy reports indicated that the cyclone was
  strengthening, and during the morning a reconnaissance flight found
  winds of 58 kts at 450 m.  An update was issued at 1300 UTC upgrading
  the depression to Tropical Storm Helene, and the first regular advisory
  was issued at 1500 UTC.   The highest MSW reported operationally for
  Helene was 55 kts, but in post-analysis this was increased to 60 kts at
  1800 and 22/0000 UTC.  Increased shear caused the storm to later weaken
  and also caused most of the associated active weather to be displaced
  well to the east of the center.    The center of Helene made landfall
  about 7:00 AM locally (1200 UTC) near Fort Walton Beach, Florida, with
  winds of only 35 kts and quickly weakened into a depression.

     The author spent the night of the 21st in Fort Walton Beach at the
  home of a friend and co-worker.  We had dinner in a restaurant over-
  looking the beach and then walked out to the end of a fishing pier
  which extends about 300 ft (~100 m) into the Gulf.  We estimated that
  the waves breaking on the beach were about 3 ft (1 m) in height.  At
  one point during the wee hours of the morning I woke up and looked
  out the door to see the rain coming down nearly horizontally, but the
  next morning there were only a few small twigs and pine needles on my
  car.   At around 7:00 AM--the time of landfall--I walked outside and
  the wind was completely calm.

     The only fatality reported in association with Tropical Storm Helene
  was a man killed in an F2 tornado in South Carolina as the tropical
  depression moved through the region on 23 September.  Near Tallahassee,
  Florida, the storm dumped almost 230 mm of rain, causing extensive
  flooding, but no damage figures are available.

                         Hurricane Isaac  (TC-13)
                         21 September - 2 October

     Hurricane Isaac was a classically-forming Cape Verde hurricane which
  followed a rather smooth parabolic track over the eastern and central
  Atlantic.  The storm attained Category 4 status on the Saffir/Simpson
  scale as its winds climbed to an estimated peak of 120 kts--tying Isaac
  with Hurricane Keith as the most intense hurricanes of the season.  The
  official storm report on Isaac, prepared by Richard Pasch, can be found
  at the following URL:>.   I
  recommend that interested readers first connect to TPC/NHC's website
  and read Richard's report, which contains a tabular listing and plot of
  the analyzed "best track" as well as plots of meteorological

     Since my purpose here is to complement the storm report already
  available on NHC's website, and since Isaac remained far from any
  populated shores, there is not a whole lot to write.   A few slight
  modifications to the operational MSW values were made in the "best
  track".  Operationally, Isaac was not upgraded to a hurricane until
  23/1800 UTC, but the "best track" shows it reaching hurricane intensity
  six hours earlier.   Between its two periods of Category 3 intensity,
  when the hurricane underwent some shearing, the operational MSW did
  not drop any lower than 80 kts, but in the post-storm review the MSW
  was decreased to 75 kts for a twelve-hour period on 26 September.

     Isaac's initial intensification to Category 3 status in the far
  eastern Atlantic on 24 September was quite unusual, especially
  considering that its winds climbed to 105 kts over SSTs less than
  27 C.   Another very interesting aspect of the storm becomes evident
  when perusing a tracking map of all the Atlantic tropical cyclones for
  the season.   Hurricane Isaac's track was amazingly close to the track
  of earlier Hurricane Alberto.   Both cyclones began in almost the
  same location, and the two tracks veritably lie on top of each other
  in several spots.  Isaac passed about 200 nm farther east of Bermuda
  than did Alberto, but the storm's tracks cross again near 50W.  At
  this point Alberto's track begins the huge week-long clockwise loop
  whereas Isaac's continues on a straight shot toward the British Isles.

     Although Isaac remained far from U. S. shores, passing about 450 nm
  east of Bermuda, swells generated by the large, powerful hurricane
  were responsible for the capsizing of a boat off Long Island.  One man
  on board the boat reportedly drowned before he could be rescued.

                         Hurricane Joyce  (TC-14)
                         25 September - 2 October

     Joyce was another Cape Verde hurricane which formed on the heels of
  Isaac.  However, in stark contrast to the earlier hurricane, which
  recurved and intensified into a Category 4 storm on the Saffir/Simpson
  scale, Joyce followed a slightly oscillating westward track at low
  latitudes--always remaining south of 13N--and peaked at only 80 kts.
  The official storm report on Joyce, prepared by Miles Lawrence, can be
  found at the following URL:>.
  I recommend that interested readers first connect to TPC/NHC's website
  and read Miles' report, which contains a tabular listing and plot of
  the analyzed "best track" as well as plots of meteorological

     After Joyce had formed in the eastern Atlantic on 26 September not
  all that far away from Hurricane Isaac--at 26/1200 UTC Joyce was only
  about 700 nm southeast of the hurricane--it seemed logical to think
  that the new storm would follow a track similar to Isaac's.  However,
  a mid-level ridge which had built in behind the earlier storm kept
  Joyce moving on a westward track throughout its entire life.

     Probably the biggest question which has been raised regarding Joyce
  is:  What caused the storm to dissipate in an environment where shear
  was not particularly great and there were plenty of warm SSTs?  There
  seems to be a fairly good consensus of opinion that dry air entrainment
  was the major factor in Joyce's weakening when other factors seemed
  to be favorable for a major hurricane to approach the Lesser Antilles.
  Roger Edson argues that a lack of southwesterlies to the south of the
  cyclone, and hence a lack of tropical moisture from the equatorial
  region, was the major reason for the drier-than-normal environment
  surrounding Joyce.

     Hurricane Joyce was very similar in many regards to Hurricane Cora
  of August, 1978.  Both storms formed in the same general area, reached
  an estimated peak intensity of 80 kts, weakened as they approached the
  Windward Islands, and dissipated in the southeastern Caribbean Sea.
  The annual seasonal summary article for 1978, as published in _Monthly
  Weather Review_ (April, 1979, Vol. 107, No. 4), coincidentally was also
  written by Miles Lawrence.    To quote from that article:  "Rapid
  dissipation as Cora moved into the southeast Caribbean is not an
  unexpected event in this area.  The entrainment of continental air from
  South America limits convective processes in the storm and strong
  tradewind easterlies produced by the geographic heat low disrupt the
  low-level circulation.  Large-scale criteria were generally favorable
  otherwise for intensification, and yet the circulation completely
  disappeared within 24 hrs, which indicates the significance of
  continental influences."

     Another interesting tidbit from Miles' earlier report was the state-
  ment that Cora was only the third Atlantic tropical cyclone to be 
  upgraded to hurricane status solely on the basis of satellite pictures.
  Prior to 1978 the only Atlantic hurricanes so classified on the basis
  of satellite imagery alone were Doris and Gladys of 1975.  It's rather
  interesting to realize that what is nowadays a routine occurrence was,
  less than a quarter-century ago, considered a new and novel thing.

                        Hurricane Keith  (TC-15)
                        28 September - 6 October

     Hurricane Keith was one of the two most intense hurricanes of the
  season, the other being Hurricane Isaac.  Both hurricanes reached
  Category 4 status on the Saffir/Simpson scale with the MSWs peaking
  at 120 kts.   While Isaac remained far out in the mid-Atlantic, Keith
  wandered slowly around the extreme northwestern Caribbean Sea, brushing
  coastal regions of Mexico's Yucatan Peninsula and Belize as well as
  some offshore islands before weakening and making landfall as a strong
  tropical storm.     The storm later re-intensified over the Bay of
  Campeche and made a second landfall in northeastern Mexico as a strong
  Category 1 hurricane.     The official storm report on Keith, prepared
  by Jack Beven, can be found at the following URL:>.    I recommend that
  interested readers first connect to TPC/NHC's website and read Jack's
  report, which contains a tabular listing and plot of the analyzed
  "best track" as well as plots of meteorological information.

     Several months ago I asked Eric Blake if he would consider writing
  a report on Keith for me.  Eric agreed to do so, and the remainder of
  the discussion of this hurricane is Eric's report basically as he sent
  it with only minimal editing by myself.    I'd like to extend a very
  special thanks to Eric for writing the summary for Hurricane Keith.

     Keith's origins can be traced to a tropical wave that emerged off
  the west coast of Africa on 16 September.  The wave continued moving
  slowly westward without development as it encountered strong vertical
  shear.  The first signs of significant development were on 27 September
  when convection flared near the center of the system in the western
  Caribbean Sea.    Aircraft reconnaissance found a 1004-mb tropical
  depression on 28 September just east-northeast of the Honduran coast-
  line, moving slowly in a general northwesterly direction.    The
  depression was under a well-defined upper anticyclone and it
  intensified into a tropical storm the next day.  

     Keith then began a period of unexpected rapid intensification
  shortly after 1800 UTC on the 29th when it was only about 125 nm from
  land.    Well-defined banding features were noted and it became a
  hurricane on the 30th.   Its pressure fell from 1000 mb to 939 mb in
  about 36 hours and the storm reached its estimated maximum intensity
  of 120 kts on 1 October.  During this intensification a large area of
  cloud tops with temperatures colder than -80 C were noted and a
  circular, 15-20 nm wide eye emerged.  The hurricane continued to drift
  slowly to the west during this time, very near the coast of Belize with
  its dangerous eyewall over the coastal islands.    There were also
  reports of the shallow Bay of Chetumal emptying with the constant north
  to northwest winds.

     The cyclone meandered for about two days off the Belize coast,
  drifting slowly and erratically in a general westward direction.  The
  hurricane weakened gradually due to increasing easterly shear, some
  mixing of cooler water from well below the surface of the northwest
  Caribbean Sea, and increasing interactions of the inner core with land.
  Keith made a first landfall as a Category 1 hurricane on Ambergris Cay
  near 2300 UTC on the 2nd.  However, this island likely received winds
  of Category 3 strength or higher as it was in the hurricane's powerful
  eyewall for about 24 hours before the hurricane weakened.    Keith
  diminished further into a tropical storm as it drifted westward,
  crossing the Belize coastline with a MSW of 60 kts around 0300 UTC on
  the 3rd between Belize City and Chetumal, Mexico.

     The system continued to weaken as it headed inland, becoming a
  tropical depression at 1200 UTC on the 3rd.    It changed direction
  slightly, moving more to the west-northwest.  A ridge over the northern
  Gulf of Mexico was providing a stronger steering current, and a gradual
  acceleration took place over the next two days.   The environment was
  favorable for re-intensification over the Gulf of Mexico, and Keith
  intensified into a strong Category 1 hurricane before landfall.
  Weather radar from Tampico indicated that the system was well-developed
  when it made landfall, with a pronounced eye and well-defined spiral
  bands.     The hurricane moved ashore about 40 km north of Tampico,
  Mexico, around 1800 UTC on the 5th with maximum sustained winds near
  80 kts.

     Media reports indicate that 19 people died as a result of the storm,
  with most of the deaths occurring in Belize and Nicaragua due to 
  flooding.    Keith's slow motion led to incredibly large rainfall
  totals, most notably over 813 mm at the Phillip Goodson International
  Airport in Belize City.  It is likely that higher amounts fell to the
  east and north closer to the core of the stalled-out hurricane.
     The maximum intensity of Keith is not an easy thing to determine.
  Aircraft reconnaissance were only flying twelve-hour missions near the
  probable time of maximum intensity, common practice in the northwestern
  Caribbean.  The Hurricane Hunter nearest the time of maximum intensity
  only recorded a flight level wind of 118 kts at 700 mb, which normally
  would not support an intensity of 120 kts in the best-track.  However,
  a dropsonde indicated peak winds of 153 kts in the southeastern eyewall
  at a level of about 883 mb.  This dropsonde did not report winds below
  904 mb, though.  In addition another sonde in the southwestern eyewall
  recorded a wind of 122 kts about 30 m off the surface, and a wind of
  140 kts at a level of about 70 m.    Unfortunately, neither of these
  dropsondes recorded winds near the surface.     However, Keith's
  convection was very intense and it seems plausible that the strong
  winds at 30 m could have easily been transported to the surface.
     The maximum flight-level wind at 850 mb was 133 kts, which would
  reduce to about 115 kts at the surface.  However, this maximum wind was
  recorded more than 16 hours AFTER the minimum pressure was recorded in 
  Keith.  It appears that the winds were actually increasing more at the
  surface than at the 700-mb level and the normal flight-level-to-surface
  reduction factors do not apply well to this hurricane, or perhaps any
  rapidly-developing storm.  Another interesting point is that objective
  T-numbers on Keith exceeded 7.0 for a number of hours, equating to an
  intensity of 140 kts or higher.  This seems unlikely given twelve-hour
  Air Force reconnaissance and is another example of the benefit of
  having some ground truth observations.
     The minimum pressure estimation of Keith requires some further
  explanation.  The lowest central pressure reported by a dropsonde was
  942 mb, but this sonde reported a surface wind exceeding 40 kts.  This
  indicates that the sonde likely did not hit the area of lowest
  pressure, and the National Hurricane Center has estimated a minimum
  central pressure of 939 mb for the best-track database.
     It is also worth noting that this storm gave forecasters a hard time
  at the National Hurricane Center, especially while it was still in the
  Caribbean Sea.     Most of the forecasts issued had an error in both
  intensity and track that were well above the ten-year mean.  There does
  appear to be some similarities with Hurricane Mitch in 1998, which was
  in the same general location at the same basic time of year.    A
  comparison between the two storms shows that forecasts for both storms
  were trying to take the storms too quickly to the north whereas both
  hurricanes were generally stationary in the northwestern Caribbean for
  a number of days, and neither was forecast to rapidly intensify.


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

  Activity for September:  3 tropical storms
                           1 hurricane

  NOTE:  Much of the information presented below was obtained from the
  TPC/NHC discussion bulletins issued with every regular advisory (CPHC
  for locations west of 140W.)  All references to sustained winds imply
  a 1-min averaging period unless otherwise noted. 

               Northeast Pacific Tropical Activity for September

     The average number of tropical storms forming in the Northeast
  Pacific basin in September is about three with two reaching hurricane
  intensity.   This year four tropical cyclones formed during the month
  but only one became a hurricane, the other three systems being short-
  lived, minimal tropical storms.  The hurricane, Lane, remained offshore
  but did, in its later stages, move somewhat farther north than usual,
  dissipating well to the west of San Diego, California.     Tropical
  Storms Miriam and Norman, although weak, did produce some slight
  effects along portions of the Mexican coastline.  Kristy was a very
  brief storm which was a minimal tropical storm for only about 18 hours
  on 2 September about halfway between Mexico and Hawaii.

                      Tropical Storm Kristy  (TC-13E)
                          31 August - 3 September

     Tropical Storm Kristy was a short-lived, minimal tropical storm
  which blossomed briefly about halfway between Hawaii and Mexico.  The
  storm was the easternmost developing disturbance associated with an
  outbreak of enhanced convective activity in the Central and Eastern
  North Pacific regions in late August, the others being Tropical Storm
  John and an unnamed system south of Hawaii for which no warnings were
  issued (which I dubbed "Mu" based on an opinion from Mark Lander that
  tropical storm intensity was likely reached).  (See the August summary
  for discussions of those two systems.)  The earliest mention by TPC/NHC
  of the pre-Kristy disturbance seems to have been in a Tropical Weather
  Outlook issued at 1700 UTC on 29 August.  The system was located over
  1100 nm southwest of Cabo San Lucas and contained minimal thunderstorm

     Over the next couple of days the disturbance drifted slowly westward
  and gradually became better organized.   Advisories were initiated on
  TD-13E at 2100 UTC on 31 August with the center located roughly 1425 nm
  west-southwest of Cabo San Lucas or about 1325 nm east-southeast of
  Hilo, Hawaii.  The depression was sheared with the LLCC located to the
  northeast of the main area of convection, and the initial intensity
  was set at 25 kts.  TD-13E remained essentially stationary for the
  next day or so, being embedded in a large col region in the subtropical
  ridge axis, and was slow to intensify.     Last visible images on
  31 August as well as a SSM/I overpass at 0605 UTC on 1 September showed
  a good mid-level circulation, but at the lower levels the circulation
  was broad with possible multiple vortices and little deep convection
  near the main circulation center.  A large convective burst developed
  over the center around 01/0800 UTC which led to the MSW being bumped
  up to 30 kts.  This burst soon faded away, but a second burst occurred
  during the morning and was a little better organized than the first
  with a weak banding pattern around the center.

     By 02/0000 UTC satellite intensity estimates from both TAFB and SAB
  had reached 35 kts, so the depression was upgraded to Tropical Storm
  Kristy at 0300 UTC.  However, overnight the storm lost most of its
  deep convection and did not intensify beyond minimal tropical storm
  intensity.  Convection fluctuated and remained somewhat disorganized,
  but by 02/1800 UTC the low-level center was completely exposed and
  Kristy was downgraded to a depression.  The warning positions had
  suggested a slow westward drift, but visible images warranted a
  relocation of the center back eastward to near its point of origin.
  By 0000 UTC on 3 September the LLCC had become elongated and separated
  from a few spots of deep convection.     The system appeared to be
  embedded in the ITCZ, and the final advisory was issued at 0300 UTC.

                         Hurricane Lane  (TC-14E)
                             5 - 14 September

     The final hurricane in the NEP basin this season formed from a
  tropical wave which left the coast of Africa around 19 August.  The
  wave propagated westward across the Atlantic and Caribbean, reaching
  the Eastern Pacific by the 30th.     A 1008-mb LOW had formed by
  3 September southwest of the Gulf of Tehuantepec.  Ship reports early
  on the 3rd indicated winds as high as 35 kts in squalls, but the low-
  level center appeared to be displaced well to the southeast of the
  strongest convection.   The disturbance continued to move to the west-
  northwest off the southern Mexican coast, and by the afternoon of the
  4th showers and thunderstorms had become more concentrated near the
  LOW which was located a couple hundred miles south-southeast of
  Manzanillo.       Advisories on TD-14E were begun at 1500 UTC on
  5 September as the system exhibited some banding features and strong
  convection near the estimated center which was located approximately
  200 nm south-southwest of Manzanillo, Mexico.    The depression was
  upgraded to Tropical Storm Lane on the next advisory with satellite
  intensity estimates solidly supporting tropical storm intensity;
  however, a ship with call sign VRUZ9 had recently reported winds of
  only 12 kts near the center, thereby casting some doubt upon the 
  Dvorak intensity estimates.

     Lane continued to intensify in the near-term.  Winds were up to
  45 kts by 06/0300 UTC and were further increased to 50 kts at 0900 UTC.
  Ship VRUZ9 reported winds of 27 kts about 70 nm north of the center at
  0000 UTC, so the strongest winds were confined to a very small area
  near the center.   There was little evidence of any banding features,
  and Lane's center early on 6 September appeared to be near the northern
  side of a convective burst.  Around 1200 UTC vessel ELX27 reported west
  winds of 30 kts and a pressure of 1003 mb about 80 nm south of the
  estimated position of the center.    Some evidence of northeasterly 
  shear was beginning to be seen over the storm which put a halt for the
  moment to the intensification process.   Lane was embedded in a broad
  low- to mid-level tropospheric trough which extended westward from the
  coast of Mexico to near 120W.  This steering environment caused the
  cyclone's westward progress to slow and come to a halt.    Visible
  pictures around 1800 UTC revealed that the partially-exposed LLCC was
  located to the southeast of the previous position estimates.

     Tropical Storm Lane's appearance continued to deteriorate as it
  became trapped in a large ITCZ-like band of low-level cyclonic flow and
  convergence which competed with the storm's inflow.  The northeasterly
  shear also was detrimental to the storm, and the MSW was lowered to
  40 kts at 0300 UTC on the 7th as the convection near the center had
  become increasingly ragged.  On infrared imagery Lane appeared as a
  broad circulation with several clusters of deep convection but without
  an inner core.   Dvorak T-numbers had decreased to T2.5 from TAFB and
  SAB by 1200 UTC, so the MSW was lowered to 35 kts in the 1500 UTC
  advisory.  Six hours later a banding feature west and south of the
  center had developed so the intensity was increased to 40 kts; however,
  at 0300 UTC on 8 September Lane was downgraded to a depression about
  325 nm southwest of Manzanillo.  The LLCC that was being followed
  had popped out from under the convection during the afternoon and
  progressively became less defined, eventually losing its identity
  within the broad area of low pressure.   NHC decided to hang on to
  Lane as a tropical depression in the interest of avoiding potential
  confusion in case the larger LOW should consolidate into a tropical

     That decision proved to be a good one as by 0600 UTC Dvorak numbers
  had jumped into the 45-55 kt range, based on the development of a
  large, cold CDO-feature.  It was impossible to determine from infrared
  imagery if a LLCC had formed beneath the convection, but the CDO was
  impressive enough that Lane was re-upgraded to a 35-kt tropical storm.
  During the 48 hours from around 1200 UTC on 6 September through 1200
  UTC on the 8th, Lane had described a somewhat erratically-shaped
  counterclockwise loop.   By 08/1200 UTC the tropical cyclone was moving
  slowly northwestward under the steering influence of a large mid- and
  upper-level ridge over northwestern Mexico.   The MSW was increased to
  55 kts at 2100 UTC based on unanimous Dvorak estimates of T3.5 from
  the three agencies, and six hours later Lane was upgraded to a 65-kt
  hurricane about 350 nm south of Cabo San Lucas on the tip of the Baja
  California peninsula.   A 25-nm cloud-filled eye had become visible
  on satellite images.   The storm at this time was moving northwestward
  at 8 kts.   The hurricane-force winds were confined to a very small
  area near the center, but based upon 0000 UTC ship reports from waters
  west of Manzanillo, the zone of gale-force winds was expanded out to
  275 nm to the northeast--the coastal gales likely due to funneling
  effects of the high terrain.   Lane at this time was a large storm in
  terms of gales: winds 34 kts or higher covered an area exceeding 500 nm
  in diameter.

    The rapid intensification trend which brought Lane up to hurricane
  force leveled off some.   By 1200 UTC on 9 September the MSW was raised
  to 70 kts as the storm with its banding-type eye passed very near or
  over Socorro Island where a minimum pressure of 973.7 mb was reported.
  The hurricane reached its peak estimated intensity of 85 kts at 0000
  UTC on 10 September when it was located approximately 200 nm southwest
  of Cabo San Lucas.   The minimum estimated CP was 970 mb, and Lane at
  this time was sporting an eye 60 nm in diameter.  Due to the large
  size of Hurricane Lane, squalls with strong gusty winds, heavy rain,
  high seas and pounding surf were forecast to occur along both coasts
  of the Baja and along the Mexican west coast north of Manzanillo.
  The peak intensity of 85 kts was maintained for 18 hours and then Lane
  began to slowly weaken as it began to approach and move over cooler
  SSTs.  The MSW was dropped to 80 kts at 10/2100 UTC even though the
  storm's convective pattern had become more symmetric.  The cloud tops
  were beginning to warm and Dvorak T-numbers were beginning to come
  down.   Lane continued to slowly spin down as it moved on its north-
  westerly track well to the west of Baja California.

     The storm was downgraded to a 60-kt tropical storm at 1800 UTC on
  the 11th, and by 12/0000 UTC very little convection remained near the
  system's center.    The MSW was lowered to 55 kts on the 0300 UTC
  advisory and continued to drop with each new advisory.  The outflow
  pattern became increasingly asymmetric and northward-oriented--evidence
  of increased vertical shear over the system.  A trough to the northwest
  of the storm caused Lane to recurve to the north and northeast.  During
  the evening of the 12th a burst of convection occurred near the center
  of Lane despite its being located over 21 C waters.     Water vapor
  imagery indicated that the burst was likely due to interaction with a
  negatively-tilted upper-level shortwave trough passing just southwest
  of the storm.    Lane had weakened into a minimal tropical storm by
  0600 UTC on the 13th when it reached the westernmost point of its track
  about 450 nm west of Punta Eugenia, Mexico.   The system was downgraded
  to a depression at 1200 UTC, and the final warning on Lane was issued
  at 0300 UTC on 14 September with the center of the swirl of low clouds
  located about 250 nm west-southwest of San Diego, California.  Moisture
  from Lane spread over portions of California, Nevada, and Oregon.

                      Tropical Storm Miriam  (TC-15E)
                             15 - 17 September

     Tropical Storm Miriam was a short-lived, minimal tropical storm
  which brushed the tip of the Baja California peninsula.  The Tropical
  Wave log prepared by John Wallace does not connect Miriam with a wave
  of African origin.  The first mention of the pre-Miriam disturbance
  in a TWO from TPC/NHC was at 1700 UTC on 8 September.  An area of
  disturbed weather was then located a few hundred miles south-southeast
  of the Gulf of Tehuantepec, so it seems very possible that a tropical
  wave from the Caribbean which had crossed Central America was the
  precursor of Miriam.   The disturbance moved slowly westward for the
  next several days off the southern Mexican coast.  On the 8th and 9th
  the system seemed to be getting better organized, but it ran into a
  less favorable environment on the 10th which put further development
  on hold for a few days.   As late as 14 September upper-level winds
  were still somewhat hostile, but by the 15th conditions were becoming
  more favorable for development and convection had become more
  concentrated near the center.  The first advisory on TD-15E was issued
  at 15/2100 UTC placing the center about 175 nm west of Manzanillo,
  Mexico--south of the mouth of the Gulf of California.

     Convection associated with the depression disappeared during the
  diurnal minimum but had begun to make a comeback early on the 16th.
  Satellite intensity estimates were 35 kts at 0600 UTC, but ship C6LF9,
  located near the center, reported only 20-kt winds and 1007.1 mb, so
  the depression was not upgraded at 0900 UTC.   The system was upgraded
  to Tropical Storm Miriam at 1500 UTC with 35-kt winds although the
  appearance in satellite imagery was not much improved over that of the
  previous day.   Miriam was located about 225 nm west-northwest of
  Manzanillo moving slowly north-northwestward in the general direction
  of Cabo San Lucas.   Visible satellite images during the day showed an
  unimpressive-looking system with ragged convection.  An upper-level
  cyclone over the central Baja was producing some southwesterly shear
  over the storm.  The last visible pictures of the day revealed an
  exposed LLCC south of the previous position and southwest of the deep
  convection.  Nonetheless, Dvorak classifications were slightly higher
  due to the certainty of the center, and Miriam's MSW was bumped up to
  40 kts--the peak for the storm.     The cyclone was centered about
  125 nm southeast of Cabo San Lucas at this time and was moving north-
  westward at only 5 kts.

     Six hours later satellite intensity estimates were still 40 kts but
  the MSW was dropped back to 35 kts based on a QuikScat wind analysis.
  By 17/1200 UTC QuikScat data indicated no winds of tropical storm
  force associated with the system and Miriam was downgraded to a
  tropical depression near the tip of the Baja peninsula.  Satellite
  imagery during the afternoon revealed that the circulation had
  dissipated in the southern Gulf of California and the final advisory
  on Miriam was issued at 2100 UTC.  The remnants of the depression were
  still generating intermittent convection over the southern Gulf and
  adjacent land areas.  Heavy rains in association with Miriam likely
  fell over portions of the Baja peninsula, but the author has learned
  of no damage or casualties resulting from this tropical cyclone.

                     Tropical Storm Norman  (TC-16E)
                            20 - 22 September

     Like Miriam, Tropical Storm Norman was a minimal tropical storm
  which had a short career, but unlike the earlier storm, did make
  landfall in Mexico--twice, in fact.   Again, as was the case with
  Miriam, I am unable, based on the information available to me, to
  say with certainty whether or not Norman developed from a tropical
  wave of African origin.  The first mention of the pre-Norman system
  in a TWO from TPC/NHC (1100 UTC on 16 September) indicated that a
  westward-moving area of disturbed weather was located just southwest
  of the Gulf of Tehuantepec.    This suggests that the disturbance
  likely did originate on the Caribbean side of Central America.  By
  very early on the 19th disturbed weather extended along and just off-
  shore from an extensive area of the Mexican coastline:  from the Gulf
  of Tehuantepec to Cabo Corrientes.  A weak LOW was embedded in the
  disturbed area about 200 nm south of Manzanillo but was showing no
  imminent signs of development.  However, during the morning convection
  began to increase and by afternoon was becoming fairly well-organized.
  The 4:00 PM PDT Tropical Weather Outlook indicated that a tropical
  depression could form within the next day or two.

     The first advisory on TD-16E was issued at 0300 UTC on 20 September.
  The initial location was roughly 150 nm south-southeast of Manzanillo.
  Outflow had improved and central deep convection had increased with
  a large area of very cold cloud tops of -85 to -88 C on the western
  side of the center.   Embedded in a weak steering flow pattern, the
  depression was drifting northward at only 2 kts.  At 1200 UTC ship
  3ESU8 reported 38-kt winds and a SLP of 1001.5 mb, and at 1300 UTC
  ship LADQ4 reported winds to 39 kts and a SLP of 1003.0 mb.  Therefore,
  TD-16E was upgraded to Tropical Storm Norman at 1500 UTC with the MSW
  estimated at 40 kts.   The center of Norman was just south of the
  coast about 115 nm southeast of Manzanillo or about 75 nm west-
  northwest of Zihuatanejo.  The cyclone still exhibited very cold cloud
  tops of -83 C and further strengthening was considered a possibility
  before landfall.  Norman at this time was moving north-northeastward
  at 6 kts.

     At 1800 UTC Norman's center was difficult to pinpoint but was likely
  located on the Mexican coastline.    Satellite intensity estimates
  from TAFB, AFWA, and SAB were 45 kts, 45 kts, and 35 kts, respectively,
  so the MSW remained at 40 kts.   Almost immediately after making land-
  fall, Norman began to track to the west-northwest parallel to and just
  inland from the coast, likely due to a mid- and upper-level anticyclone
  located over Mexico.   The cyclone was downgraded to a depression at
  21/0300 UTC and never regained tropical storm intensity even though
  the center later re-emerged over water.    Norman passed just to
  the north of Manzanillo around 0600 UTC on the 21st with peak sustained
  winds estimated at only 25 kts.   By 22/0000 UTC the center of the
  depression had moved back over the Pacific near Cabo Corrientes and
  was moving at a slightly faster pace toward the northwest.

     The MSW was increased slightly to 30 kts after the system had moved
  back over water based on a 22/0105 UTC QuikScat pass.  The QuikScat
  data showed westerly rain-contaminated winds of 35 to 40 kts south of
  the center, which equates to about 30-32 kts corrected surface winds.
  A large convective complex was noted north of the center and also
  inland over Mexico.  While environmental conditions would have favored
  some re-intensification, interaction with the Mexican landmass
  inhibited any further strengthening of the depression.    Norman
  turned to the north after 22/0600 UTC, and surface reports and first
  visible pictures on the 22nd indicated that the small circulation
  center was making landfall near Mazatlan.   After moving inland Norman
  continued to move northward, and the final advisory was issued at
  2100 UTC.

     Some media sources reported that at least 8 persons died in Mexico
  within 24 hours from a tropical depression on the Gulf coast and from
  Tropical Storm Norman on the Pacific coast.  There was no tropical
  depression in the Gulf of Mexico during this period, but there was a
  disturbance in the Bay of Campeche which on 19 September did appear to
  be organizing rapidly at one point, prompting a reconnaissance flight
  into the area.    This area weakened on the 20th as the outflow from
  Norman streamed across the region.  In the city of Tapachula (in the
  state of Chiapas), four persons died in mudslides and rockslides.
  Tapachula lies along the extreme southeastern coast near the Guatemalan
  border, so these fatalities were not associated with Norman.  Neither
  were two deaths which were reported in Veracruz state.  However, there
  were two deaths by drowning reported in Guerrero state which were due
  to the heavy rains of Norman.  The center of Norman made landfall in
  the state of Michoacan which lies just to the west of Guerrero.


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

  Activity for September:  3 tropical storms ** 
                           2 typhoons ++
                           2 super typhoons

  ** - one of these was treated as a tropical storm only by JTWC, and
       another is included based upon Mark Lander's assessment that it
       reached tropical storm intensity

  ++ - one of these (Sonamu) was not upgraded to typhoon status by JMA

  NOTE: Most of the information on each cyclone's history presented in
  the narrative will be based upon JTWC's advisories, and references to
  winds should be understood as a 1-min avg MSW unless otherwise noted.
  However, in the accompanying tracking document I have made comparisons
  of coordinates with JMA (Japan) and the Philippines (PAGASA) when their
  positions differed from JTWC's by usually 40-50 nm or more.  A special
  thanks to Michael V. Padua, owner of the Typhoon 2000 website, for
  sending me the PAGASA and JMA tracks.

     In the title line for each storm I plan to reference all the cyclone
  names/numbers I have available:    JTWC's depression number, the
  JMA-assigned name (if any), JMA's tropical storm numeric designator,
  and PAGASA's name for systems forming in or passing through their area
  of responsibility.

              Northwest Pacific Tropical Activity for September

     An active September followed on the heels of an active August in the
  Northwest Pacific basin.     Five tropical cyclones were named by JMA
  with four becoming typhoons.  (This per JTWC's classification--JMA did
  not upgrade Sonamu to a typhoon.)  Two of the typhoons, Saomai and
  Shanshan, reached super typhoon status as winds climbed to 130 kts.
  (Again, this based upon JTWC's 1-min avg MSW values.)  Typhoon Saomai
  passed over Okinawa after weakening from super typhoon status and later
  made landfall in South Korea.   Shanshan spent its entire life east
  of 165E--an unusual area for a super typhoon to occur.   Early in the
  month Typhoons Saomai and Wukong and Tropical Storm Bopha were all
  progressing simultaneously for several days.   Wukong passed over the
  extreme southern tip of Hainan Island and made landfall in Vietnam.
  Bopha followed a very unusual course, being driven southward by the
  large circulation of Super Typhoon Saomai.  The storm moved almost
  due southward off the east coast of Taiwan and made landfall on the
  northern end of Luzon.

     Typhoon Sonamu was a very small typhoon which formed near Iwo Jima
  and moved northward, remaining east of Japan.   Also around mid-month
  another small TUTT-induced system formed several hundred miles south-
  east of Japan.  No warnings were issued on this system, but Dr. Mark
  Lander of the University of Guam believes that it reached tropical
  storm intensity.   A track is included for this system, which I have
  designated with the Greek letter "Nu", in the cyclone tracks file.

     Finally, near the end of the month, another weak system formed to
  the north of Wake Island and was designated as Tropical Depression 27W
  by JTWC.  JTWC later upgraded this system briefly to tropical storm
  status, but JMA carried it only as a depression; hence, it was not

              Super Typhoon Saomai (TC-22W / TY 0014 / Osang)
                             2 - 18 September

  Saomai: submitted by Vietnam, is the Vietnamese name for the planet

     Saomai was a long-lived typhoon which became the year's third super
  typhoon in the NWP basin.  The storm traced out a long trajectory from
  its point of origin well to the east of the Marianas which took it
  directly over Okinawa and eventually into South Korea.   Saomai's peak
  intensity of 140 kts (per JTWC) was reached while southeast of Okinawa,
  but fortunately the storm had weakened considerably before striking
  the island, although it was still a potent typhoon.   The daily STWO
  issued by JTWC on 1 September discussed an area of convection located
  approximately 700 nm east of Guam which apparently had persisted from
  the previous day.  (Unfortunately, I cannot locate the STWO for 31
  August.)   Convection had been pulsating for a couple of days around
  a LLCC, but the center was too weak to maintain the convection.  An
  upper-level ridge was over the area with a TUTT to the northwest.
  CIMSS analysis indicated weak vertical shear over the disturbance and
  the development potential was upgraded to Fair.

     A Formation Alert was issued for the system at 02/0130 UTC.
  Animated satellite imagery indicated improving organization during the
  previous six hours with convection developing west of the LLCC.
  Outflow over the disturbance was fair and vertical wind shear was weak.
  The first warning on TD-22W was issued at 12/1200 UTC, placing the
  center about 700 nm east-northeast of Guam.   The system was smaller
  than average (about 130 nm in diameter), and a 02/1057 UTC SSM/I pass
  revealed deep convection increasing near the center and to the west.
  The environment was favorable for strengthening and JTWC upgraded the
  depression to a 35-kt tropical storm on the second warning (1800 UTC).
  The tropical cyclone moved on a straight westerly course on 3 September
  and began to intensify rather quickly.  JMA upgraded the system to a
  tropical storm at 03/0600 UTC and assigned the name Saomai.   By
  1200 UTC Saomai had developed a central cold cover with temperatures
  to -84 C.  Outflow was good over the system, and by 1800 UTC the storm
  was approaching typhoon strength with both JTWC and JMA estimating
  peak sustained winds of 55 kts (both 1-min and 10-min avg).

     JTWC upgraded Saomai to a typhoon at 0000 UTC on 4 September with
  the storm centered approximately 425 nm east-northeast of Guam.  The
  MSW was increased to 70 kts at 0600 UTC since a 04/0236 UTC TRMM pass
  depicted a developing eyewall; however, infrared satellite imagery at
  this time did not reveal a warm spot (indicative of eye formation).
  Saomai continued to increase in intensity on the 4th with JMA upgrading
  the storm to a typhoon at 1200 UTC.  By 1800 UTC the MSW reached an
  initial peak intensity of 90 kts (per JTWC) while JMA estimated the
  maximum 10-min avg winds at 70 kts.  A warm spot had become evident in
  imagery; however, the storm was also showing some signs of increasing
  vertical shear caused by an upper-level anticyclone to the northwest
  of the typhoon.   A TRMM pass at 04/2033 UTC indicated that much of
  the convection had been sheared to the south of the LLCC, although a
  narrow band of convection was wrapping into the center from the north.
  JMA downgraded Saomai to a tropical storm at 0600 UTC on the 5th when
  the storm was located about 85 nm northeast of Saipan (or about 200 nm
  northeast of Guam), and JTWC followed suit six hours later.

     By 1200 UTC Saomai was moving slowly southward, steered by a sub-
  tropical ridge to its southwest.  This southward motion continued until
  around 0000 UTC on 6 September when the storm reached a point roughly
  190 nm east of Guam.   The MSW dropped to 55 kts (50 kts per JMA) and
  maintained this strength for the next 48 hours.   A 06/0758 UTC Quik-
  Scat pass showed that the strongest winds were located in the southeast
  quadrant.  By 0600 UTC the storm had embarked on a northwesterly track
  which it was to follow for over a week.   Tropical Storm Saomai was
  located about 80 nm east of Saipan at 1800 UTC where a pressure of
  991 mb and sustained winds of 15 kts were recorded.   Convection was
  making a comeback with improved banding west and southwest of the
  center.  A low- to mid-level ridge to the northeast of the system
  was the primary steering influence at this juncture.  Around 0000 UTC
  on 7 September Saomai moved through the Marianas island chain, passing
  about 60 nm north of Saipan near Anatahan Island.  The storm exhibited
  a partially-exposed LLCC on the northern edge of the convection.

     After passing the Marianas Saomai continued moving northwestward at
  around 12-14 kts with little change in intensity or structure.  Outflow
  was good over the southern semicircle but an upper-level LOW to the
  northeast was inhibiting outflow on the northern side.   By 08/0000 UTC
  the storm's organization had increased and a CDO about 140 nm in
  diameter had formed.  JTWC re-upgraded Saomai to a typhoon, placing the
  center approximately 400 nm south of Iwo Jima.  (JMA, however, did not
  upgrade the storm to typhoon intensity for another 24 hours.)  Hints
  of a developing eye were seen around 0600 UTC, and JTWC had increased
  the MSW estimate to 85 kts by 1800 UTC.   Deep convection was present
  over the LLCC and a large inflow was evident in satellite imagery.
  Typhoon Saomai continued to intensify on 9 September as it plodded in
  the direction of Okinawa.   A 22-nm irregular eye had become visible
  by 1200 UTC and the MSW was upped to 100 kts.   The 1800 UTC warning
  further increased the winds to 120 kts around a well-defined, 15-nm
  diameter eye surrounded by intense convection.  (JMA's maximum 10-min
  avg wind estimate had reached 90 kts by this time.)

     Saomai reached its peak estimated intensity of 140 kts at 1200 UTC
  on 10 September when the 20-nm eye was centered 280 nm east-southeast
  of Okinawa.  (JMA's maximum 10-min avg wind at this time was 100 kts.)
  50-kt winds extended 70 nm to the northeast of the center and 55 nm
  elsewhere while gales covered an area almost 350 nm in diameter.  Super
  Typhoon Saomai possessed a broad circulation with a fairly tight,
  intense inner core.     The typhoon continued to make a beeline for
  Okinawa but very fortunately began to slowly weaken.    The MSW was
  lowered to 130 kts at 11/0000 UTC, and by 1800 UTC on the 11th was
  down to 110 kts.  (JMA was reporting 90 kts.)   At 1800 UTC Saomai was
  centered 100 nm east-southeast of Naha Airport, moving toward the west-
  northwest at 6 kts.   A TRMM pass at 11/1647 UTC depicted an intense,
  symmetric system with a 33-nm circular eye, and animated satellite
  imagery revealed concentric eyewall development.

     Typhoon Saomai continued to slowly weaken as it approached and
  crossed Okinawa.   By 12/0000 UTC the eye had become cloud filled and
  defined solely by the convective bands.   Kadena AB (WMO 47931) was
  reporting northerly sustained winds of 27 kts with gusts to 44 kts.
  A 12/0045 UTC SSM/I pass depicted a concentric eyewall with strong
  banding to the south.   At 0755 UTC Kadena AB was reporting northerly
  winds of 48 kts with gusts to 76 kts and a SLP of 958 mb.  The 20-nm
  eye was centered at 12/0600 UTC only about 15 nm southeast of Okinawa
  (presumably Naha Airport, since the previous JTWC warnings had used
  that site as a reference point), and the estimated MSW was 100 kts.
  (JMA's maximum 10-min avg wind had dropped to 75 kts by this time.)

     The storm crossed over the central part of the island during the
  late afternoon (local) of 12 September.   At 0830 UTC the exact center
  of Saomai's eye was located about 6 nm east-southeast of Kadena AB,
  and by 1500 UTC had moved to a position about 36 nm north-northwest of
  the base.   Yoron Island (WMO 47942), north of Okinawa, reported
  sustained winds (1-min avg) to 65 kts.   By 1800 UTC the storm was
  centered about 65 nm west-northwest of Naha Airport with the MSW
  estimated at 90 kts (per JTWC).    Yoron Island, which was located
  beneath a strong convective band, reported 63-kt sustained winds (1-min
  avg) and a SLP of 980.2 mb around 1800 UTC.    Kadena AB reported peak
  gusts to 45 kts and a pressure of 971.7 mb, and was still reporting
  sustained winds of 28 kts (10-min avg) and gusts to 42 kts at 0000 UTC
  on the 13th.  The heaviest precipitation was confined to the eastern
  semicircle of the typhoon at this time.

     After passing Okinawa Typhoon Saomai continued moving rather slowly
  to the northwest through a weakness in the subtropical ridge.  The
  storm remained in a more or less steady state intensity-wise on 13 and
  14 September with the MSW in the 85-90 kt range (per JTWC) and the
  maximum 10-min avg winds estimated at around 70-75 kts by JMA.  At
  13/0600 UTC the typhoon's center was located about 320 nm south of
  Cheju Island, South Korea.  A buoy (WMO 22001), located approximately
  30 nm north of the center, reported 54-kt sustained winds and a SLP
  of 962 mb.   Six hours later the same buoy was about 15 nm east of the
  typhoon's center and was reporting 45-kt sustained winds and a SLP of
  968 mb.   By 1800 UTC Saomai had slowed some in its forward motion and
  was moving westward at 5 kts.  Infrared imagery revealed an irregular,
  ragged eye, and microwave imagery indicated a thin eyewall with a
  larger band of convection south of the center.

     Saomai reached the westernmost point of its long track at around
  0600 UTC on 14 September when it was located approximately 185 nm east
  of Wenchou, China.   The storm had intensified slightly from 85 to
  90 kts, and began to turn slowly to the north due to a mid-latitude
  trough to its northwest.  Infrared imagery showed that the system was
  beginning to elongate along a north-south axis.  Vertical shear was
  still weak but forecast to increase as the storm moved farther to the
  north.   By 14/1800 UTC Saomai was indeed beginning to weaken as
  evidenced by warming of the cloud tops and deterioration of the eye.
  Microwave imagery revealed a partially-exposed LLCC with convection
  being advected northward.   After recurvature the weakening storm
  initially moved slowly east-northeastward, then began to accelerate
  to the northeast.   At 1200 UTC on the 15th Saomai passed about 300 nm
  east of Shanghai, moving north-northeastward at 20 kts with winds of
  minimal typhoon intensity.   Cloud tops had continued to warm and
  what significant convection remained was isolated near the center of
  the low-level circulation, although SSM/I imagery showed a very weak
  convective band in the southeastern quadrant.

     By 1800 UTC Saomai's center was approximately 80 nm southwest of
  Pusan, South Korea, and continuing to accelerate toward the coast.
  JMA had downgraded the typhoon to a tropical storm, and while JTWC
  was still maintaining Saomai as a minimal typhoon, the remarks in
  the warning indicated that the storm was beginning to undergo extra-
  tropical transition.  Animated water vapor imagery depicted cold air
  associated with a major short-wave trough pushing into the system from
  the coast of China.   Saomai made landfall around 2030 UTC at a point
  approximately 95 km west of Pusan.  At 2100 UTC Pusan reported 36-kt
  sustained winds from the south with a pressure of 979.5 mb.   JTWC
  issued their final warning on the system at 0600 UTC on 16 September
  with the now-extratropical system located over the Sea of Japan about
  170 nm northeast of Seoul, South Korea, and tracking rapidly just east
  of due north at 28 kts.  What convection remained was displaced north
  of a fully-exposed LLCC.     The extratropical remnants of Saomai
  continued to move northward over the western Sea of Japan, passing
  back inland near Vladivostok, Russia, and remained identifiable over
  eastern Siberia for a few more days.

     Strangely, I cannot locate any references to any damage or
  casualties caused by this typhoon.   If any should become available
  later they will be reported in a future summary.  I did receive some
  rainfall amounts from Patrick Hoareau of Rennes, France.  Naha (on
  Okinawa) recorded 183 mm in the 48 hours ending at 13/0000 UTC.
  Dinghai, in China's Zhejiang province, measured 102 mm in the 18 hours
  ending at 13/0600 UTC--slightly more than half the monthly average of
  190 mm.   Kaesong, North Korea, recorded a 24-hour total of 147 mm
  from 15/0000 to 16/0000 UTC.   Also, the lowest pressure measured
  during Saomai's passage across Okinawa that I could find referenced
  in warnings from JTWC was 958 mb.   I seem to recall an e-mail which
  mentioned a 952-mb reading, but I can not find any record of this in
  my files.   If anyone can confirm this, I'd appreciate it if they
  would let me know.

  NOTE:  In looking through my files I discovered an e-mail from Mark
  Lander--which he posted late on 2 September--in which he disagreed
  with the warning intensity reported in the JTWC warnings for the
  early part of Saomai's history.  I overlooked this when I prepared the
  September cyclone tracks file back in October.  I am including here
  Mark's preliminary best track which he prepared for Saomai from 02/0000
  to 03/0000 UTC.

     DATE    TIME (UTC)   LAT     LON     MSW-1 min (kts)
  00 SEP 02    0000     16.1 N  158.6 E    25  (JTWC: none)
  00 SEP 02    0600     16.2 N  157.3 E    35  (JTWC: none)
  00 SEP 02    1200     16.2 N  156.5 E    40  (JTWC: 25 )
  00 SEP 02    1800     16.3 N  155.7 E    45  (JTWC: 35 )
  00 SEP 03    0000     16.3 N  154.8 E    55  (JTWC: 35 )

            Tropical Storm Bopha (TC-24W / STS 0015 / Ningning)
                             5 - 12 September

  Bopha: submitted by Cambodia, is the name of a flower which is used as
         a little girl's name

     Tropical Storm Bopha certainly had the most unusual track of any
  NWP basin tropical cyclone so far this year.  The storm formed several
  hundred miles to the southeast of Okinawa and ahead of the intensifying
  Saomai.   The storm moved west-northwestward and passed near Okinawa
  just as Saomai was beginning to rapidly deepen into a super typhoon.
  The large circulation of the intense Saomai drove Bopha on a very
  unusual southward course parallel to the east coast of Taiwan and
  eventually into northern Luzon.   I am unable to trace the origin of
  Bopha with certainty due to some missing STWOs.  The storm may be
  related to a disturbance which was mentioned on 1 September, located
  about 450 nm southeast of Okinawa.  Animated visible satellite imagery
  showed disorganized convection sheared to the west of a LLCC.  I do
  not have the STWO for the 2nd, but the STWO for 3 September indicates
  that this area of convection had dissipated.   No tropical disturbance
  was mentioned in the STWO for 4 September except the pre-Wukong system
  in the South China Sea.  Unfortunately, I am missing the STWO for the
  5th, which was the day that PAGASA initiated warnings on a tropical
  depression about 500 nm southeast of Okinawa at 0600 UTC, assigning
  the name Ningning.   JMA began including information on the depression
  in their High Seas Bulletins at 1200 UTC while at the same time PAGASA
  upgraded Ningning to a tropical storm.

     JTWC issued a Formation Alert for the system at 05/1600 UTC,
  followed by the first warning on TD-24W at 1800 UTC.  JTWC estimated
  the MSW at 25 kts, while JMA reported the maximum 10-min avg wind at
  30 kts and PAGASA at 35 kts.   JMA upgraded the system to Tropical
  Storm Bopha at 06/0000 UTC when it was centered approximately 550 nm
  southeast of Okinawa.   The system initially moved slowly northeast-
  ward before curving to the northwest as it came under the steering
  influence of a low- to mid-level ridge to its northeast.   It is
  interesting that JTWC's intensity estimates were well under those
  from JMA during the early portion of Bopha's history.  JTWC finally
  upgraded Bopha to a tropical storm at 07/0000 UTC when the system
  was centered approximately 475 nm east-southeast of Okinawa.  The
  remarks in the JTWC warning indicate that the warning intensity
  (35 kts) was based upon satellite current intensity estimates ranging
  from 25 to 55 kts--JMA's 10-min avg wind estimate at the time was
  50 kts.  Animated satellite imagery depicted a fully-exposed LLCC with
  convection sheared about 30 nm to the north.     A 200-mb analysis
  indicated that Bopha was under moderate vertical shear beneath the
  subtropical ridge axis.

     By 1800 UTC the tropical storm was centered about 200 nm east-
  southeast of Okinawa and moving west-northwestward at 16 kts.  The
  center was still exposed and satellite intensity estimates ranged from
  35 to 55 kts, but the MSW was increased to 45 kts, likely influenced
  by a report of 38-kt sustained northerly winds from a ship west of
  Bopha's center.   Over the next 12 hours the convection increased in
  areal extent and became more concentrated over the LLCC, and at 0600
  UTC on the 8th Bopha reached its peak intensity of 55 kts (per JTWC).
  (JMA's estimated maximum 10-min avg wind remained at 50 kts during
  this period.)   The storm was centered at this time about 50 nm south-
  east of Naha, Okinawa, where 30-kt sustained east-northeasterly winds
  were reported at the airport (WMO 47936).  Bopha continued moving to
  the west-northwest, passing just to the south of Okinawa.  Kadena AB
  reported a peak wind of 40 kts at 0926 UTC (not sure if this reading
  is sustained or a gust).   By 1800 UTC the cyclone was centered about
  125 nm west of Okinawa--this proved to be the northernmost point of
  its track.   Six hours later Bopha was moving south-southwestward at
  5 kts due to the influence of the larger and steadily-intensifying
  Typhoon Saomai, located then about 700 nm to the east-southeast.
  The tropical storm was also beginning to weaken.  Microwave imagery
  showed a ring of weak convection about the system with some stronger
  cells wrapping into the LLCC, and QuikScat data indicated very weak
  winds in the southeast quadrant and an elongation of the wind field.

     Bopha continued to move south-southwestward roughly parallel to the
  east coast of Taiwan, passing about 175 nm east of Taipei at 09/0600
  UTC.   The storm continued to weaken as it experienced shear from
  Typhoon Saomai.   By 0000 UTC on 10 September the storm was located
  about 120 nm east-northeast of the southern tip of Taiwan.  Winds had
  dropped to 40 kts, but the JTWC warning remarked that the system had
  moved into a more favorable environment.  Convection became better
  organized with a deep convective band on the western and southern sides
  spiraling toward the center, and the MSW was upped to 50 kts at 0600
  UTC and briefly to 55 kts once more at 1200 UTC.   Bopha was at this
  time located about 115 nm north of Port San Vicente, Luzon, still
  moving south-southwestward at 11 kts.

     However, as the cyclone approached northern Luzon, it ran into
  increasingly stronger vertical shear and began to weaken.  At 0000 UTC
  on the 11th the center had just about reached the coastline of north-
  eastern Luzon, and the MSW had dropped to 45 kts (40 kts per JMA).
  The system was being sheared apart with the upper-level clouds
  streaming to the west-southwest while the LLCC had begun to move to
  the south-southeast.   The JTWC warning for 11/0600 UTC indicated that
  a synoptic report of 40-kt winds had been reported near the center
  (which was over Luzon), but the location wasn't specified.   Bopha
  was downgraded to a tropical depression (by both JTWC and JMA) at
  1200 UTC when the center was near Ilagan.   The dissipating depression
  subsequently turned eastward and moved back out over the Philippine
  Sea with the final JTWC warning at 12/0000 UTC placing the center
  about 125 nm east of Casiguran.

                Typhoon Wukong (TC-23W / TY 0016 / Maring)
                              2 - 10 September

  Wukong: submitted by China, is the king of the monkeys.  Featured in
          the classic novel _Journey to the West_.

     While Super Typhoon Saomai and the weaker Tropical Storm Bopha were
  dancing about in the open Pacific, Typhoon Wukong formed in the South
  China Sea and pursued a fairly straight track westward across the
  southern tip of Hainan Island and into northern Vietnam, becoming a
  respectable 95-kt (per JTWC) typhoon along the way.    An area of
  convection formed on 1 September approximately 360 nm north-northwest
  of Palau.  Animated visible satellite imagery showed disorganized
  convection sheared to the west of a LLCC.   As noted in the discussion
  of Tropical Storm Bopha above, I am missing the STWO for the 2nd.
  However, PAGASA initiated warnings on the disturbance at 02/0000 UTC,
  placing the center about 350 nm east-northeast of Catanduanes Island
  and naming it Maring.   Maring initially jogged to the north, then
  took off on a westerly track towards Luzon.  That the system was
  poorly-organized and difficult to track is evidenced by several huge
  "jumps" (i.e., relocations).     At 03/0000 UTC Maring was relocated
  approximately 180 nm to the west-northwest of its previous warning
  position.      The STWO issued by JTWC at 0600 UTC also mentions this
  relocation to a position about 140 nm east of Luzon.    JTWC at this
  time was not treating the system as a depression but did assign a Fair
  development potential.

     The PAGASA warning on Maring at 1200 UTC placed the broad center
  about 75 nm east-southeast of the northeastern tip of Luzon, but at
  1800 UTC the depression's center was relocated to a position 200 nm to
  the west-northwest, or about 75 nm north-northwest of Laoag on north-
  western Luzon.   And at 0000 UTC on 4 September Maring was relocated
  yet again to a position approximately 165 nm west-southwest of Laoag.
  In the meantime, the STWO from JTWC at 04/0600 UTC indicated that the
  disturbance east of Luzon from the previous days had dissipated.  The
  remarks indicated that a LLCC had developed in the South China Sea
  about 180 nm west of Luzon.   This location is very near PAGASA's
  0600 UTC position for Tropical Depression Maring.   Whether this South
  China Sea circulation (which ultimately became Wukong) is the same
  disturbance noted east of the Philippines a few days earlier or a
  completely new development is perhaps open to question.  

     As the day progressed the system appeared to weaken and PAGASA
  issued a final warning at 04/1800 UTC.  However, six hours later JMA
  began treating the system as a tropical depression in their High Seas
  Bulletins, and JTWC issued a Formation Alert at 05/0300 UTC, noting
  that convection had intensified over the previous few hours near a
  partially-exposed LLCC.  JTWC issued the first warning on TD-23W at
  0600 UTC on the 5th, locating the center about 350 nm south-southeast
  of Hong Kong and essentially stationary.    Also at 0600 UTC PAGASA
  re-initiated warnings on Maring, upgrading it to a 35-kt tropical
  storm.  The system was located in an environment of moderate easterly
  vertical shear, so intensification proceeded at a slow rate.  A low-
  level ridge to the south steered Maring/23W on a slow easterly track
  initially, but after around 1800 UTC the system began to move to the
  north.  JMA upgraded the system to a tropical storm at 06/0000 UTC,
  naming it Wukong.   JTWC still had the MSW assessed at 30 kts while
  PAGASA was reporting a peak 10-min avg wind of 40 kts.  At this stage
  Wukong exhibited a broad LLCC with a strong band of convection and
  strongest winds to the south of the center.

     JTWC classified Wukong as a tropical storm at 0600 UTC on the 6th
  when the system was centered approximately 300 nm southeast of Hong
  Kong.    The storm was moving to the north-northwest at 5 kts and
  gradually turned to a westward track as a subtropical ridge to the
  north began to build.   By 1200 UTC CIMSS satellite-derived winds
  products indicated weak vertical shear with good diffluence over the
  area, and significant intensification was not long in coming.  The MSW
  was up to only 40 kts at 1800 UTC (although JMA's 10-min avg wind
  estimate was 50 kts), but convection had begun to increase in areal
  extent and consolidate around the center.    However, at 0000 UTC on
  7 September JTWC abruptly upgraded Wukong to a 65-kt typhoon located
  about 235 nm south-southeast of Hong Kong.  Animated satellite imagery
  indicated that the system had rapidly gained in organization, and a
  06/1934 UTC TRMM pass depicted tightly curved convective bands.  The
  storm by this time was tracking westward at 9 kts, a course from which
  it never significantly deviated for the rest of its life.

     Although Wukong had rapidly strengthened from a minimal tropical
  storm into a typhoon, the intensification trend levelled off and the
  system remained a minimal typhoon for the next 24 hours.  (JMA upgraded
  Wukong to a typhoon at 07/1800 UTC.)  Overall organization improved
  even though convection weakened slightly.  A 07/1311 UTC SSM/I pass
  depicted eyewall convection around the system except for the southern
  quadrant with a convective band to the southwest.   Typhoon Wukong
  passed about 200 nm due south of Hong Kong at 0000 UTC on 8 September.
  Animated water vapor imagery revealed good outflow aloft over the
  storm and the organization was improving.  JTWC increased the MSW to
  75 kts at this time and to 90 kts at 0600 UTC.  (JMA's 10-min avg wind
  estimate rose to its peak value for the storm's history--75 kt--at
  0600 UTC.)   A TRMM pass at 08/0224 UTC revealed a ragged eyed 45 nm
  in diameter.

     The typhoon exhibited a slight weakening around 1800 UTC, losing its
  eye feature in infrared imagery.  JMA decreased the intensity to 70 kts
  but JTWC maintained the MSW at 90 kts.   As Wukong continued on toward
  the southern tip of Hainan Island it re-intensified some, reaching its
  peak intensity of 95 kts (per JTWC) at 09/0000 UTC as it neared the
  island.  The estimated MSW was based on satellite intensity estimates
  of 90 and 102 kts.   Microwave imagery indicated a well-defined center
  with deep convection consolidated in the southern semicircle.   By
  0600 UTC on the 9th Wukong was located over the extreme southern tip of
  Hainan and moving westward at 10 kts.      The storm was beginning to
  weaken and the MSW was lowered to 75 kts.  (JMA downgraded Wukong to
  a 60-kt tropical storm at 0600 UTC.)   Wukong's intensity continued to
  decrease further as it plodded westward across the Gulf of Tonkin, and
  JTWC dropped the MSW to 65 kts at 1200 UTC.  By 0000 UTC on the 10th
  the storm was nearing the coast of northern Vietnam, and although
  microwave imagery indicated the redevelopment of a large eye, Wukong
  was downgraded to a 60-kt tropical storm.     All the convection was
  located along the southern side of the LLCC.   The tropical cyclone
  made landfall and began to weaken quickly.  At 10/0600 UTC JTWC issued
  their final warning, placing the center of Wukong about 150 nm south of
  Hanoi.  The MSW was estimated at 45 kts, based on a synoptic report of
  40 kts just north of the center.   JMA issued one more bulletin, down-
  grading the storm to a depression.  The remnants of Wukong continued
  moving westward toward central Laos and northeastern Thailand.

     Media reports indicate that Wukong left 5 dead with one person
  missing in Hainan province.  Over 2700 homes and 70,000 hectares of
  crops were destroyed while 240,000 hectares of crops were damaged and
  nearly 2.5 million persons adversely affected by the typhoon.   In
  Vietnam's Ha Tinh province, where the storm made its final landfall,
  two persons were reported killed and 69 injured.  Wukong's heavy rains
  and 60-kt winds destroyed nearly 3000 homes--leaving 10,000 homeless--
  and blew the roofs off 5000 others.  In addition 11,000 hectares of
  rice were submerged, power lines downed, and some sea dyke systems
  breached by the torrential rains and storm surge.

                         Tropical Cyclone "Nu"
                           13 - 18 September

     The discussion of this system is based almost completely upon
  information supplied by Dr. Mark Lander of the University of Guam,
  who supplied the track for this cyclone which was included in the
  global cyclone tracks file.   Mark's track first defines a weak
  tropical depression at 0600 UTC on 13 September about 425 nm north-
  west of Wake Island.    Over the next day or two the system moved
  rather quickly to the northwest, gradually turning to the north-
  northwest.     By 15/0000 UTC the cyclone had reached its point of
  recurvature about 700 nm east of Tokyo.   In Mark's opinion the system
  had reached tropical storm intensity at this point.  A visible picture
  taken at 14/2230 UTC shows a small, bright convective area with very
  pronounced spiral bands feeding into the CDO.  Mark estimates that the
  MSW was 40 kts around this time.    An intermediate STWO issued by JTWC
  at 14/2300 UTC mentioned this area and indicated that it appeared to be
  developing rapidly.  The system was given a Fair development potential
  and a Formation Alert was issued at 15/0000 UTC.   A recent QuikScat
  pass supported the existence of a LLCC beneath the convection with
  winds of 20-25 kts.  

     However, the small cyclone turned toward the east-northeast and
  quickly weakened.  Mark's track weakens the system to 30 kts by 1200
  UTC, and JTWC cancelled the Formation Alert at 1800 UTC.  Convection
  had decreased significantly and the exposed LLCC had moved north of
  the upper-level ridge axis beneath moderate westerlies.  The weak
  system continued moving generally eastward for about 24 hours and then
  sprang back to life with another burst of convection.  Mark estimates
  that the system had regained tropical storm intensity by 1200 UTC on
  16 September and that it reached its peak MSW of 45 kts at 1800 UTC
  when it was centered approximately 900 nm east of Tokyo.  An infrared
  image taken at 1130 UTC reveals a circular area of cold cloud tops
  seemingly over or very near the LLCC.  Following this flare-up the
  system began to weaken again and drifted toward the south and later
  toward the west-southwest.  The final entry in Mark's track at 0600
  UTC on 18 September places the dissipating center about 950 nm east-
  southeast of Tokyo.

                     Typhoon Sonamu  (TC-25W / STS 0017)
                              14 - 21 September

  Sonamu: Korean word for pine tree, contributed by the Democratic
          People's Republic of Korea (North Korea)

     An area of convection formed on 13 September roughly 400 nm south-
  west of Iwo Jima and by early on the 14th had moved to a position
  approximately 200 nm southwest of the island.  JTWC issued a Formation
  Alert at 0430 UTC for the system as convection had become increasingly
  organized.   Synoptic and scatterometer data indicated a possible
  LLCC beneath the convection.  Vertical wind shear was weak and the
  environment was favorable for strengthening.  By 0600 UTC animated
  satellite imagery indicated that the system was organizing quite
  rapidly and warnings were initiated on TD-25W.  The depression was
  moving east-northeastward at 9 kts in the general direction of Iwo
  Jima.   The MSW was increased to 30 kts at 1200 UTC and to 35 kts
  at 1800 UTC when the cyclone was centered about 130 nm southwest
  of Iwo Jima.  (JMA had designated the system as a depression at
  1200 UTC but did not upgrade it to a tropical storm until 0600 on
  the 15th.)  The minimal tropical storm was being steered northeast-
  ward by a low-level ridge to the south but was forecast to begin
  tracking northward after about twelve hours due to the influence
  of a subtropical ridge to the east.

     JTWC increased the MSW to 40 kts at 15/0000 UTC, and JMA upgraded
  and named the system Sonamu at 0600 UTC.  By this time Sonamu was
  located about 75 nm south of Iwo Jima and the expected northward
  turn was taking place.  The storm was rather small with the radius of
  gales estimated to be only 50 nm.     Animated satellite imagery
  around 1800 UTC indicated a possible developing eye and also a deep
  convective band developing southeast of the vortex center; therefore,
  the MSW was upped to 60 kts (JMA's maximum 10-min avg wind estimate
  was 50 kts).   Tropical Storm Sonamu continued to move toward the
  north-northeast and had reached a position about 25 nm east of Iwo
  Jima by 0000 UTC on 16 September.  Animated satellite imagery depicted
  a tiny cloud-filled eye only 3 nm in diameter with an associated
  primary spiral band wrapping in toward the LLCC from the southwest.
  JTWC upgraded Sonamu to a 65-kt typhoon based on the formation of the
  eye and satellite intensity estimates of 55 and 77 kts.  At 15/2300 UTC
  Iwo Jima reported sustained winds of 21 kts (10-min avg) from the
  northwest with gusts to 33 kts.  (JMA increased their maximum 10-min
  avg wind estimate to 55 kts, which was the peak for the storm's
  history--that agency did not upgrade Sonamu to a typhoon.)

     By 0600 UTC Typhoon Sonamu was located about 80 nm north-northeast
  of Iwo Jima and moving northward at 12 kts.   The island was then
  reporting sustained southwest winds of 22 kts (10-min avg) with gusts
  to 31 kts.  The MSW was increased to 70 kts at 1200 UTC based upon
  satellite imagery which revealed improving organization.  The typhoon
  was centered about 30 nm northwest of Chichijima Island which was
  reporting 35-kt sustained winds (10-min avg).   Sonamu continued to
  track toward the north, accelerating to 20 kts by 17/0000 UTC when
  it was centered about 300 nm south-southeast of Tokyo.  Most of the
  deep convection was to be found in the northeast quadrant while the
  southwest quadrant was virtually convection-free.  JTWC bumped the
  MSW up to 75 kts at 0600 UTC on the 17th--this was the storm's peak
  intensity per that agency's analysis.  Animated visible satellite
  imagery revealed improving organization and a 13-nm irregular eye.
  Sonamu by this time was located about 200 nm southeast of Tokyo
  and moving north-northeastward at 21 kts.   The translational speed
  had increased to 29 kts by 1200 UTC as the typhoon passed 170 nm east
  of Tokyo.  Sonamu was maintaining its intensity and exhibited a banding
  eye with tightly curved bands.

     The storm continued to move rapidly north-northeastward in advance
  of a major shortwave trough over South Korea and eastern China.  Sonamu
  was able to maintain its intensity due to its tracking beneath an
  upper-level ridge axis, but by 1800 UTC deep convection was beginning
  to weaken as the storm moved over 20 to 22 C SSTs.   The MSW was still
  estimated to be 75 kts at 0000 UTC on the 18th, but visible satellite
  imagery depicted a mid/high cloud shield extending several hundred
  miles northwest of the vortex center, indicative of an extratropical
  system.  An upper-level wind analysis at 17/1800 UTC indicated that
  Sonamu was situated beneath the polar front jet with winds of 60 kts
  from the southwest.  In addition water vapor imagery indicated a cold
  air tongue pushing in toward the vortex from the southwest.  Almost no
  convection was left and JTWC declared Sonamu to be extratropical at
  18/0000 UTC and issued their final warning, placing the center about
  240 nm northeast of Misawa, Japan.    The vigorous storm, however, was
  still estimated to be packing winds of 75 kts (55-kt 10-min avg wind
  from JMA) even as it transitioned into an extratropical cyclone.  The
  extratropical storm raced rapidly to the northeast for the next 
  24 hours, passing through the Aleutian Island chain into the Bering
  Sea where it became quasi-stationary and remained for several more
  days while slowly filling.

                 Super Typhoon Shanshan  (TC-26W / TY 0018)
                               17 - 27 September

  Shanshan: contributed by Hong Kong, China, is a fairly common pet name
            for young girls

     An area of convection formed on 15 September near 15N just west of
  the Dateline.  A QuikScat pass indicated a developing LLCC with 20-kt
  sustained winds.   JTWC issued a Formation Alert at 16/0230 UTC as
  imagery indicated that deep convection was increasing near the LLCC
  and low-level cloud lines were becoming evident west of the center.
  The disturbance developed slowly and a second Formation Alert was
  issued 24 hours later.   The first warning on TD-26W was issued at
  1200 UTC on the 17th, placing the center about 450 nm southeast of
  Wake Island or about 400 nm north of Majuro Atoll in the Marshall
  Islands.  Convection was becoming better organized and a 17/0640 UTC
  QuikScat pass indicated 20-25 kt winds near the LLCC.  The depression
  continued to slowly strengthen and JTWC upgraded the system to a 40-kt
  tropical storm at 0000 UTC on 18 September.    Satellite current
  intensity estimates were 30 and 45 kts, and animated imagery depicted
  rapid consolidation of the deep convection during the previous three
  hours with a 34-nm CDO over the LLCC and a spiral band wrapping into
  the center from the east.  (JMA began issuing bulletins on the system
  at 18/0000 UTC but did not upgrade it to a tropical storm until 1200
  UTC.)  The cyclone's center at 0000 UTC was located about 390 nm
  southeast of Wake Island (or 475 nm north of Majuro) and was tracking
  west-northwestward at 7 kts within a weakness in the subtropical ridge.

     The MSW was increased to 50 kts at 0600 UTC and to 55 kts at 1200
  UTC when JMA upgraded the system to a tropical storm and named it
  Shanshan.  Convective organization had continued to improve with an
  increase in spiral banding wrapping in toward the LLCC.  A TUTT north-
  west of Shanshan was helping to enhance the outflow.   Expanding areal
  coverage of the deep convection with cooling cloud top temperatures
  was observed over the next 18 hours, and JTWC upgraded Shanshan to a
  typhoon at 0600 UTC on the 19th when the storm was centered roughly
  200 nm southeast of Wake Island.  Shanshan jogged northward a bit about
  this time but soon resumed a slow, northwesterly motion.  Hints of a
  developing eye were seen at 1200 UTC, and by 1800 UTC a 25-nm
  irregular, cloud-filled eye had developed.   The typhoon was then
  located about 175 nm east of Wake Island, and JTWC increased the MSW
  estimate to 90 kts while JMA upgraded Shanshan to a typhoon with
  maximum 10-min avg winds of 70 kts.

     By 0600 UTC on the 20th Shanshan's winds had climbed to 100 kts (per
  JTWC's warnings).  The typhoon displayed a 7-nm diameter eye, and
  animated water vapor imagery depicted good outflow aloft with a mid-
  level ridge building northeast of the storm.     Typhoon Shanshan
  continued to intensify as it tracked slowly northwestward.  The MSW
  reached 125 kts at 1800 UTC when the eye was centered approximately
  120 nm north-northeast of Wake Island.  However, satellite imagery
  revealed that the southern half of the eyewall had collapsed and
  the storm's intensity plateaued at 125 kts for about 18 hours.  But
  by 1200 UTC on 21 September Shanshan had begun to strengthen again
  and JTWC increased the MSW to 130 kts, thus qualifying Shanshan for
  super typhoon status.  The storm had excellent outflow in all quadrants
  and a 25-nm round eye.  Six hours later Shanshan reached its peak
  estimated intensity of 135 kts, based upon satellite current intensity
  estimates of 127 and 140 kts.   The 17-nm diameter eye was then
  centered about 275 nm north-northwest of Wake Island and was moving
  north-northwestward at 8 kts under the steering influence of a mid-
  level HIGH situated to the northeast.  50-kt winds extended outward
  90 nm to the northeast and 50 nm elsewhere while gale-force winds
  covered an area about 320 nm in diameter.  (The peak 10-min avg wind
  estimate from JMA was 95 kts from 21/1200 through 22/0600 UTC.

     Super Typhoon Shanshan maintained its peak intensity for about
  twelve hours and then began to slowly weaken.  At 0600 UTC on the 22nd
  the MSW was decreased slightly to 130 kts as the storm turned to
  a northerly course.  Six hours later Shanshan was moving slowly to the
  north-northeast and convection was beginning to weaken.  The storm
  was downgraded from super typhoon status with the MSW being estimated
  at 115 kts.  A 22/0939 UTC SSM/I pass depicted concentric eyewalls with
  convective bands north of the eye.   The typhoon passed about 900 nm
  west of Midway Island around 1800 UTC, still slowly weakening.
  At 0000 UTC on 23 September the MSW was still estimated at 100 kts
  although there was little convection in the southwestern quadrant.
  By 0600 UTC Shanshan was beginning to experience increased vertical
  shear from the southwest, and the forward motion had increased slightly
  to 14 kts.   Six hours later the MSW was down to 90 kts (JMA's maximum
  10-min avg wind estimate was 75 kts) and Shanshan's translational speed
  had increased to 17 kts.  A 23/1342 UTC TRMM pass revealed an exposed
  LLCC with all the convection to the north of the center.

     By 24/0000 UTC Shanshan was a minimal typhoon moving quickly north-
  eastward at 24 kts and was beginning to undergo extratropical
  transition as it merged with a mid-latitude system to the north-
  northwest.  The final JTWC warning at 24/0600 UTC indicated that the
  storm had become fully extratropical at a position about 600 nm west-
  northwest of Midway.  The winds were estimated at 60 kts and the storm
  was moving northeastward at 33 kts.   JMA was still treating Shanshan
  as a minimal typhoon, but six hours later issued their final bulletin
  and declared the storm to be extratropical.  Over the next few days the
  storm continued to move northward in the vicinity of the Dateline,
  eventually turning northeastward and weakening to a 40-kt gale by
  27 September a few hundred miles south of the Aleutian Islands.

     While Super Typhoon Shanshan did not significantly affect any land
  areas, it was notable for the location in which it occurred.  According
  to Mark Lander, who reviewed some studies of typhoon climatology, it
  is highly likely that Shanshan was the first known storm to reach super
  typhoon intensity north of 20N and east of 155E.

                         Tropical Storm (TC-27W)
                            28 - 30 September

     Tropical Storm 27W was a short-lived tropical cyclone which popped
  up in the waters north of Wake Island and moved northward for a couple
  of days before dissipating.     JMA treated the system as a tropical
  depression only; therefore, no name was assigned.   However, as was
  the case with the other unnamed tropical storm (TS-28W in early
  October), there were a couple of synoptic ship observations which seem
  to support minimal tropical storm intensity.   The cyclone had its
  beginnings in an area of convection which developed about 200 nm north-
  northwest of Wake Island on 27 September.   A 27/1009 UTC SSM/I pass
  (85 GHz data) indicated increasing organization with some banding
  features developing, so JTWC upgraded the development potential to
  Fair in a special STWO at 1400 UTC.   This trend continued throughout
  the day and a Formation Alert was issued at 2200 UTC.    The LLCC
  appeared to be embedded in the eastern extension of a monsoon trough.

     JTWC issued the first warning on TD-27W at 1800 UTC on 28 September.
  The depression was moving northward at 9 kts with increased convective
  organization and cooling cloud tops.   The system was upgraded to a
  35-kt tropical storm at 29/0000 UTC when it was located about 500 nm
  north of Wake Island.  Satellite intensity estimates were 30 kts, but
  a ship about 40 nm northwest of the LLCC reported winds of 35 kts.
  The tropical storm was located in a moderate vertical shear environment
  and the deeper convection was sheared northeast of the center.  Another
  35-kt ship report six hours later (from 60 nm northwest of the center)
  sufficed to keep the system classified as a tropical storm for one more
  warning cycle.   An approaching mid-latitude trough was creating the
  shear and also was steering the system to the north-northeast.   The
  center was exposed with the deeper convection about 17 nm northeast
  of the LLCC.

     The system was downgraded to a tropical depression at 29/1200 UTC
  as it continued moving to the north-northeast and began to merge with
  the frontal boundary ahead of the trough.  By 1800 UTC on 30 September
  the system had become extratropical and the final warning was issued
  placing the center about 600 nm north of Wake Island or 775 nm west
  of Midway.


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

  Activity for September:  No tropical cyclones

  NOTE:  A low-pressure area which persisted in the Bay of Bengal for
  several days in late August and early September moved inland near the
  head of the Bay on 1 September.  A bulletin from the IMD on 2 September
  mentioned that a depression had formed over land and at 02/0300 UTC
  was centered near 24N, 85W.    This location is well inland to the
  northwest of Calcutta and about 70 km south of Gaya.   No references
  were made to this system in any STWOs issued by JTWC and no track was
  included in the accompanying cyclone tracks file.


  SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E

  Activity for September:  No tropical cyclones



  Activity for September:  No tropical cyclones



  Activity for September:  No tropical cyclones


  SOUTH PACIFIC OCEAN (SPA) - South Pacific Ocean East of Longitude 160E

  Activity for September:  No tropical cyclones


                              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 first included in the July, 1998
  summary.  I don't normally include the Glossary in most months in
  order to help keep them from being too long.  If anyone would like to
  receive a copy of the Glossary, please e-mail me and I'll be happy
  to send 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
           September as an example:   sep00.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:  sep00.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):>> OR>>>>

     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 also.

     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.  In
  addition storm reports are now available for some of the Atlantic
  tropical cyclones in 2000.

     The URL is:>

  Prepared by: Gary Padgett
  E-mail:  [email protected]
  Phone:  334-222-5327 (nights & weekends) / 850-882-2594 (weekdays)


Document: summ0009.htm
Updated: 29th December 2006

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