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Monthly Global Tropical Cyclone Summary August 2001
[Summaries and Track Data] [Prepared by Gary Padgett]

                               AUGUST, 2001

  (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.)

  SPECIAL NOTE:  Tony Cristaldi of the NWS office in Melbourne, Florida,
  rather inadvertently "discovered" a hitherto unreported tropical (or
  possibly subtropical) cyclone which occurred in the Southwest Indian
  Ocean in April.  According to Philippe Caroff of the La Reunion TCWC,
  this system formed to the south of Reunion's AOR; therefore, no
  warnings were issued on the cyclone.  This system is being researched
  and hopefully more information and a track will be forthcoming in a
  couple of months.


                            AUGUST HIGHLIGHTS
  --> Western North Pacific very active, but no typhoon landfalls
  --> Three tropical storms in the Atlantic fall just short of reaching
      hurricane intensity


               ***** Feature of the Month for August *****

                          MONSOON DEPRESSIONS

     As promised I am trying to wrap up reporting on the responses to my
  tropical cyclone survey that I sent out last March.  I have covered
  the topics of cyclone size as a possible classification criteria (May
  Feature), classification of subtropical/hybrid cyclones (June Feature),
  and warning strategies for subtropical/hybrid cyclones (July Feature).
  This month I will summarize the few opinions I received on the subject
  of monsoon depressions.  Exactly what is a monsoon depression?  The
  definition of a monsoon depression which used to be given in the Annual
  Tropical Cyclone Report published by JTWC reads as follows:

        "A monsoon depression is a tropical cyclonic vortex characterized
     by (1) its large size, the outer-most closed isobar may have a
     diameter on the order of 600 nm; (2) a loosely-organized cluster
     of deep convective elements; (3) a low-level wind distribution which
     features a 100 nm diameter light-wind core which may be partially
     surrounded by a band of gales; and (4) a lack of a distinct cloud
     system center."

     Monsoon depressions do not occur in all tropical cyclone basins.
  They are extremely rare in the Atlantic basin: one occurred in the
  western Caribbean in May, 1986, and Tropical Storm Frances of 1998
  in its earlier stages had the appearance of a monsoon depression.
  The main regions where they seem to develop most frequently are the
  North Indian Ocean, the tropical Northwest Pacific basin, the vicinity
  of northern Australia and occasionally the South Pacific.  Philippe
  Caroff of the La Reunion TCWC indicates that they are very rare in
  the Southwest Indian Ocean.  Jack Beven years ago related to me that
  an occasional Eastern Pacific tropical cyclone seemed to have monsoon
  depression characteristics.     Mark Lander has told me that on
  infrequent occasions monsoon depressions will form in the austral
  autumn over Africa south of the equator and sometimes move westward
  over the South Atlantic.  Such a system may have been responsible for
  the development of the only known South Atlantic tropical cyclone to
  date--a strong tropical depression or perhaps minimal tropical storm
  in April, 1991.   Some of the stronger African waves which move out
  into the Cape Verde region also occasionally display some monsoon
  depression features.

     Since classic monsoon depressions are an extremely rare feature in
  the Atlantic basin, the NHC forecasters who responded to my survey
  didn't have all that much to say.  James Franklin indicated that he
  would probably treat a monsoon depression (with gales) as a non-
  tropical gale center.  Jack Beven posed the question "how small does
  the core of a cyclone have to become for the system to be considered
  tropical?  From a theoretical standpoint the threshold would be when
  the tropical cyclone energetics become predominant.  From a practical
  standpoint, I don't know the right criteria or data to make such a
  determination objectively."

     Philippe Caroff, in response to the question about spatial
  distribution of gales within a circulation, indicated that for a system
  in which gales are well-removed from the center (such as in a monsoon
  depression), he felt that such gales should fairly well encompass the
  center before the system was named as a tropical storm.  Matthew Saxby
  of Australia is in favor of naming monsoon depressions with gale-force
  winds as tropical cyclones because their greater size would likely make
  them more damaging.

     David Roth of HPC writes, "I know monsoon depressions can mock
  subtropical cyclones when it comes to maximum winds being well-removed
  from the center.  Any radius should work, as long as the winds are
  caused by some direct effect of the existence of the LOW, like
  increased pressure gradient, and the system is deeply warm-core (to
  at least 500 mb)."   In his reply to the question about spatial
  distribution of gale-force winds as a criteria for classification as
  a tropical cyclone, Rich Henning wrote, "I personally don't think
  there should be a minimum for all the quadrants.  If there are 50-kt
  winds in the northeast quadrant of a monsoon-type cyclone, and only
  15 kts in the southwest is still a tropical cyclone."

     Although Mark Lander did not respond to my survey, I know from past
  correspondence and postings from Mark that he does consider monsoon
  depressions which have developed bands of gales within the circulation
  to be bonafide tropical cyclones worthy of having warnings issued.
  In a letter posted to some discussion lists in September, 1998, after
  the development of Tropical Storm Frances in the Gulf of Mexico, Mark
  pointed out that in the Northwest Pacific basin, monsoon depressions
  are the systems which are the precursors of most of the typhoons,
  especially those originating in the deep tropics.  Most monsoon systems
  which achieve winds of 30 kts go on to become "conventional tropical
  cyclones" (i.e., with organized central convection and tighter
  gradients).  Winds can increase in these systems to 50 kts in some
  portions before persistent central convection is established.  To
  quote Dr. Lander, "Attempts to say that this is due to the gradient
  between the LOW and some high pressure area, or any other line of
  reasoning to avoid calling it a tropical storm, are misleading, and
  a danger lurks.  As soon as persistent central convection develops,
  one has instantly a large, full-fledged 'conventional' tropical storm
  (or even near hurricane or typhoon), and has to suddenly go to a
  tropical cyclone warning with an embarrassingly high initial

     Mark also wrote that "the JTWC has for years had trouble with these
  systems.  People say they are not tropical cyclones; that they are
  hybrid systems of some sort; that they are not warm core--the
  explanations are legion.  Most of the time the effort goes into
  explaning why a tropical cyclone warning should not be issued on such
  systems.     Part of the problem is the Dvorak tropical cyclone
  classification system.   Largely developed from Atlantic tropical
  cyclones, Dvorak defines four basic patterns of (for lack of a better
  word) 'conventional tropical cyclones': (1) shear pattern, (2) curved-
  band pattern, (3) CDO pattern, and (4) eye pattern.    Monsoon
  depressions do not fit neatly into this scheme and are not common in
  the Atlantic.  Thus, Dvorak's techniques do not address them."

     In closing I'll include the reply I received from Julian Heming of
  the UK Meteorological Office.     Julian's reply didn't address the
  specific questions I'd raised, but rather shed light on the impact
  of the issuance or non-issuance of warnings on the performance of
  numerical models.  Julian wrote:

     "I've seen various views aired on this subject in the past and I
  probably haven't got too much to add to those who are more at the
  'cutting edge' of tropical cyclone warning strategies.  However, from
  the (UK) Met. Office's point of view, the most important thing is to
  have good information to use in initialising cyclones (be they
  tropical, subtropical, midgets, etc) in our model.  For us that means
  receipt of a warning or advisory from the relevant tropical cyclone
  warning centre.  If a warning centre decides not to name a cyclone and
  does not issue a warning because it is not a 'classical tropical
  cyclone', then our model (and I presume other models which use
  advisories in their initialisation procedures) will not have the
  benefit of information produced by tropical analysts.  This could
  possibly result in an inferior model forecast.  Of course, if a cyclone
  is too far removed from being a true tropical cyclone, then it may not
  be appropriate to use some initialisation techniques, but I think on
  most occasions having some information to feed the model is better
  than none at all.  I'm sure there will be arguments made for not
  issuing warnings until a cyclone is truly tropical, but I thought I'd
  present the viewpoint from one involved in model initialisation of
  tropical cyclones."

     I'd like to thank everyone who took the time to respond to my
  survey, and I hope that these ideas and opinions I've presented will,
  in a small way, lead to further discussions among tropical cyclone
  forecasters and researchers with the goal in mind of trying to forge
  a more globally consistent set of classification criteria and warning
  strategies for these various types of marginal tropical cyclones.

                           ACTIVITY BY BASINS

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

  Activity for August:  3 tropical storms

  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.   Some information was also obtained from the monthly
  summary for August prepared by the Hurricane Specialists and available
  on TPC/NHC's website.

                  Atlantic Tropical Activity for August

     Following Tropical Storm Allison in early June, the Atlantic basin
  remained quiet save for one short-lived minor tropical depression in
  July.  The tropical cyclone season, however, began to get underway in
  earnest early in August with the development of Tropical Storm Barry
  in the eastern Gulf of Mexico.  Barry made landfall in the Panhandle
  of Northwestern Florida during the night of 5-6 August just shy of
  hurricane intensity.    Tropical Storm Chantal developed on 16 August
  east of the Windward Islands.   The storm was moving so rapidly it lost
  its circulation and was downgraded to a tropical wave later that day.
  The next day it regained its circulation and was re-upgraded to a
  tropical storm in the central Caribbean.   Chantal moved westward and
  eventually made landfall near Chetumal, Mexico, around 0000 UTC on
  21 August as a strong tropical storm.

     Tropical Storm Dean developed rather suddenly just north of the
  Virgin Islands on 22 August.  However, the storm encountered a hostile
  shearing environment and weakened to a tropical wave the next day.
  Some of the convection associated with Dean moved northward, interacted
  with a non-tropical LOW, and eventually redeveloped into a tropical
  cyclone south of the Canadian Maritimes.  During its second incarnation
  Dean almost became a hurricane before encountering cooler waters and
  increased shear in the North Atlantic.

     Three named storms is about normal for August, but the lack of a
  hurricane is somewhat unusual--the average (1950-2000) is 1.55.  The
  last August which didn't produce a hurricane was in 1997--there were
  no tropical storms or depressions either.   The disintegration of two
  named storms back to tropical waves followed by their subsequent
  redevelopment to tropical storm intensity was also unusual.  This
  trend, strangely, continued into September as both Tropical Storm Erin
  and Tropical Depression 07 (pre-Felix) were downgraded to tropical
  waves but subsequently regained their circulations and went on to
  become major hurricanes.   

                       Tropical Storm Barry  (TC-03)
                                2 - 7 August

  A. Origins

     Barry was the first tropical storm of the 2001 season to form from
  an African tropical wave, but that development didn't occur until the
  system had reached the southeastern Gulf of Mexico.   The parent wave
  was located in the eastern Atlantic south of the Cape Verdes on 25 July
  and was moving rapidly westward.    By the 26th the disturbance was
  located around 1400 nm east of the Windward Islands.   Atmospheric
  conditions were not favorable for intensification and there was little
  associated convection.  The wave entered the eastern Caribbean area on
  29 July.  The convection was not well-organized but pressures had
  fallen a bit and the system was producing showers, thunderstorms, and
  gusty winds over portions of the Lesser Antilles.  The tropical wave
  continued westward across the Caribbean--on the 31st it was generating
  showers and thunderstorms from the central Caribbean northward across
  Hispaniola into the southeastern Bahamas; however, there were still no
  signs of increasing organization.

     Early on 1 August scattered showers and a few thunderstorms extended
  from the northwestern Caribbean northeastward across Jamaica, eastern
  Cuba, and into the Bahamas and were forecast to spread across western
  Cuba and southern Florida later in the day.  The TWO noted that some
  slow development was possible over the next day or two.  During the
  afternoon satellite imagery and surface observations indicated that
  the convection was becoming better organized near Dry Tortugas Island
  in the southeastern Gulf of Mexico.   The weak surface LOW changed
  little in organization during the night; it was interacting with a
  small upper-level LOW and upper-level winds were not favorable for
  rapid intensification.   Most models, however, suggested that tropical
  cyclogenesis would occur, and during the morning of the 2nd the LOW
  began to show signs of intensification.    TPC/NHC issued a Special
  Tropical Disturbance Statement at 1330 UTC which stated that surface
  observations and visible satellite imagery were indicating that a
  tropical depression might be forming.   An Air Force reconnaissance
  place reached the area around midday and found 48-53 kt winds at
  300 m, so the LOW was upgraded directly to Tropical Storm Barry in
  a special advisory at 1900 UTC.  Barry, which was then located about
  270 nm south-southeast of Fort Walton Beach, Florida, was more of a
  hybrid storm at that point than a purely tropical system as it was
  still sort of tangled up with the upper-level LOW.

  B. Track and Intensity History

     After being upgraded to a tropical storm, Barry strengthened
  to 40 kts as it moved slowly west-northwestward.  Late on the 3rd the
  storm slowed to an erratic drift a couple hundred miles south of the
  western Florida Panhandle, remaining in this general area until early
  on the 5th, when it began a steady northward march toward the coast.
  Barry had weakened to a minimal tropical storm by 0600 UTC on 3 August,
  and operationally remained at that intensity for 48 hours.  However,
  reconnaissance flights during the night of 3-4 August and on the 4th
  could find no tropical storm-force winds.  The Monthly Summary for
  August prepared by the staff of NHC indicates that Barry weakened to
  a depression on 3 August, and it seems likely that will be reflected
  in the final storm report and Best Track.  Since the pressure remained
  steady during this period and the circulation of Barry was large and
  well-defined, it was maintained as a minimal tropical storm in real
  time, although a couple of NHC discussions indicated that Barry very
  possibly was only a tropical depression.

     Barry began to show signs of re-intensification during the evening
  of the 4th as very deep convection with cold cloud tops reaching -81 C
  at times blossomed near the LLCC.   A reconnaissance flight around
  1200 UTC on 6 August found that the pressure had fallen 14 mb in six
  hours to 990 mb.  A special advisory was issued at 1300 UTC to post
  hurricane warnings from Pascagoula, Mississippi, eastward to the
  Ochlockonee River in northwest Florida.  Tropical storm warnings were
  already in place for portions of the coast, and these were extended
  eastward to the mouth of the Suwanee River.   Tropical Storm Barry
  reached its peak intensity of 60 kts around this time, but the
  intensification trend leveled off and the storm remained at just under
  hurricane intensity until landfall early on the 6th.

     Barry's center made landfall around the middle of the night of
  5-6 August about 30 km east of Fort Walton Beach between the Walton
  County communities of Miramar Beach and Grayton Beach.  The weakening
  cyclone continued inland across the Panhandle, moving just east of
  Crestview, and northward into southern Alabama, passing over or very
  near the author's home near Andalusia.  Barry turned to a northwestward
  track as it marched inland and had weakened to a tropical depression
  over southwestern Alabama by 1500 UTC on the 6th.   The remnant LOW
  speeded up somewhat for a time after landfall and had reached the
  Alabama-Mississippi border near Aliceville, Alabama, by 2100 UTC.
  HPC had assumed responsibility for issuing storm summaries after Barry
  was dropped by NHC, and the fourth and final HPC summary, issued at
  1500 UTC on 7 August, indicated that the weak remnants of Barry were
  located near Memphis, Tennessee.   They were last seen over south-
  eastern Missouri on the 8th.

  C. Meteorological Aspects

     Barry was upgraded to a tropical storm at 1900 UTC on 2 August.  By
  2100 UTC convection had wrapped more than halfway around the LLCC and
  outflow was good in the eastern semicircle.  A reconnaissance plane
  found 54-kt winds at 300 m and a pressure of 1008 mb.  Some south-
  westerly vertical shearing was hampering Barry at this time.  The
  NHC discussion issued at 03/0300 UTC, written by Jack Beven, provides
  a good example of some of the difficulties encountered in following
  tropical cyclones even with multiple observational platforms available.
  Reconnaissance fixes indicated that the center was moving west or west-
  northwest at about 10 kts.  However, satellite fixes, including some
  good visible pictures, suggested the center was moving north or even
  east of north.      Furthermore, data from Buoy 42003 supported the
  aircraft fixes while the Tampa WSR-88D radar supported the satellite
  positions!  The best conclusion seems to be that the center was tilted
  due to the southwesterly shear and that satellite and radar were
  tracking the upper-level center.

     Early on the 3rd, strong upper-level westerlies became established
  over Barry and the LLCC became detached from the limited convection.
  Later during the morning some convective organization was regained,
  and a reconnaissance flight found 35-40 kt winds and a pressure of
  1007 mb.  The westerly shear continued to decrease during the afternoon
  and Barry's appearance continued to improve.  However, no sooner had
  Barry begun to recover from the westerly shear when it was hit by
  strong northeasterly flow associated with a cyclonic shear axis which
  had moved over the storm.       Barry likely weakened to a tropical
  depression during the night of 3-4 August--a couple of reconnaissance
  flights could find no winds of tropical storm intensity.  However, the
  pressure had dropped to 1005 mb and satellite intensity estimates from
  TAFB and AFWA were 35 kts, so the cyclone was maintained as a minimal
  tropical storm.   A flight during the morning of the 4th reported a
  pressure of 1006 mb and winds to 39 kts south of the center.

     During the evening of 4 August another reconnaissance mission found
  flight-level winds of 44 kts and a minimum pressure of 1003 mb.  The
  storm was slowly improving in organization, and during the early
  morning hours of the 5th, Barry developed some very deep convection
  with cold cloud tops to -81 C at times near the LLCC.  The center was
  not embedded in the deepest convection but rather was on the north-
  western edge due to some west-northwesterly shear which had developed
  ahead of a shortwave trough that was digging down over Arkansas and
  Louisiana.   The MSW was increased to 40 kts at 0900 UTC based on TAFB
  and SAB estimates of T3.0.   A reconnaissance flight around 1200 UTC
  found that the pressure had fallen 14 mb to 990 mb in a six-hour
  period.  Winds were upped to 50 kts and the hurricane warnings were
  ordered for portions of the Gulf Coast.   This rapid intensification,
  however, did not continue throughout the day.  The structure of Barry
  had been changing with the development of outer banding features in the
  eastern semicircle which seems to have isolated the inner core and
  slowed the intensification process.   Also, the westerly shear over the
  storm had likely brought some drier air into the inner core.  Barry did
  not weaken, however, as a dropsonde released at 1900 UTC reported
  surface winds of 61 kts.

     During the night of 5-6 August, WSR-88D radar observations showed
  transient eyewall formations, but the inner core never became better
  defined with the eyewall remaining open over the southern semicircle.
  A reconnaissance flight at 06/0451 UTC found a 700-mb flight-level
  wind of 71 kts southeast of the center and an extrapolated minimum
  pressure of 990 mb.  The last dropsonde into the storm, at 0335 UTC,
  with the center still about 17 nm offshore, had reported a SLP of
  993 mb.    After Barry's center had made landfall and crossed over
  Choctawhatchee Bay, it passed near Eglin AFB range station C-52
  (30.6N, 86.3W) where the altimeter reached a minimum of 994.2 mb at
  0547 UTC with southeasterly winds of 25 kts, gusting to 37 kts.  The
  strongest gust was 52 kts from the northeast at 0516 UTC.    The
  peak gust reported at the Eglin Main weather station (around 15 km to
  the west-southwest) was 270/55 kts at 0627 UTC; the sustained wind at
  the time was 33 kts.   Destin, Florida, reported a gust of 37 kts
  around midnight when Barry's center was about 17 nm east-southeast
  of that location and the northern eyewall had already moved onshore.
  Cape San Blas, well to the east, reported a peak gust of 36 kts.

     Tyndall AFB near Panama City recorded 186 mm of rainfall in the
  24 hours ending at 06/1200 UTC with another 8 mm falling during the
  next six hours.  Eglin AFB had recorded 94 mm by 1400 UTC on the 6th.
  The first storm summary issued by HPC included some 5-day rainfall
  totals for Barry ending at 06/1200 UTC.  Many locations in the southern
  portion of the state experienced heavy rainfall associated with the
  tropical wave which spawned Barry and during the storm's early
  formative stages.  Tynfall AFB's 5-day total was 220 mm followed by
  204 mm at the West Palm Beach International Airport.  Fort Lauderdale
  recorded 202 mm during the 5-day period.   Quite a few locations over
  the state had totals between 150 and 175 mm.    Tallahassee recorded
  156 mm for a 5-day total ending at 1800 UTC--for the 12-hour period
  06/1200 UTC through 07/0000 UTC that site picked up 109 mm.  During
  the 30 hours ending at 1800 UTC on 6 August, Apalachicola measured
  156 mm.    The highest 3-day storm total, ending at 07/1200 UTC, was
  226 mm at Tallahassee.

     Rainfall amounts tapered off considerably as Barry weakened and
  moved across Alabama.  Maxwell AFB near Montgomery recorded a 24-hour
  total of 70 mm, ending at 07/1200 UTC, while the Shelby County Airport
  picked up 59 mm for the same period.  Some storm totals in Alabama for
  the 72-hour period ending at 07/1200 UTC include 103 mm at Troy, 89 mm
  at Ozark, and 82 mm at Maxwell AFB.   Valdosta, Georgia, well-removed
  from Barry's track, recorded 61 mm for the same period while Tupelo,
  Mississippi, measured 27 mm for a 3-day total.

  D. Damage and Casualties

     Winds and rain associated with Tropical Storm Barry caused minor
  damage in the Florida Panhandle amounting to about $30 million.  No
  deaths were attributed to the storm.

                     Tropical Storm Chantal  (TC-04)
                              15 - 22 August

  A. Origins

     Tropical Storm Chantal was one of the oddest and most troublesome
  Atlantic tropical cyclones in recent years.  It was the first of four
  consecutive "interrupted" cyclones--systems whose centers dissipated
  only to regenerate later.   Chantal was also one of the most rapid
  movers on record for the deep tropics, racing across the tropical
  Atlantic and central Caribbean at speeds of up to 25 kts at times.
  This rapid motion resulted in Chantal's having a great difficulty main-
  taining a well-defined closed circulation even after it regenerated
  in the southeastern Caribbean.   It's not far from the truth to say
  that Chantal was almost an open wave with winds to near hurricane
  force--something which "just isn't supposed to happen".  Like Barry
  before it, Chantal did slow down and become better organized and was
  near hurricane intensity when it made landfall near Chetumal, Mexico.

     A tropical wave left the west coast of Africa around 12 August,
  producing a large area of showers and thunderstorms but not very well
  organized.  By the next day there had been a slight increase in 
  convective organization and a TWO indicated that the system had some 
  potential for slow development over the next couple of days.  Early on
  the 14th the wave was even better organized, and was accompanied by a 
  broad area of low pressure but still lacked persistent central 
  convection.  By 1500 UTC on 15 August the wave had acquired enough 
  organized convection that it was upgraded to Tropical Depression 04, 
  located about 900 nm east of Barbados.  The center was poorly-defined 
  and appeared to be located east of the main convection, but since low
  shear and warm waters were ahead of the depression, intensification 
  was forecast.  A strong mid-level ridge to the north was steering 
  TD-04 westward at 20 kts or more.

     By the early morning of 16 August, TAFB was estimating 35 kts (the
  other agencies were lower), and the depression appeared to be very near
  tropical storm strength.   The NHC specialist on duty opted to wait
  until visible satellite pictures were available before upgrading in
  order to get a better handle on the center location.  The depression
  was moving westward at about 24 kts at the time.   An intermediate
  advisory was issued at 1200 UTC, upgrading the system to Tropical Storm
  Chantal, located about 325 nm east of Barbados.

  B. Track and Intensity History

     The cloud pattern of Chantal had improved since the previous day
  with banding features and excellent outflow due to an upper-level anti-
  cyclone located over the tropical cyclone.  However, there was a very
  big surprise when the first Hurricane Hunters' reconnaissance mission
  reached Chantal during the early afternoon.  The crew was not able to
  locate any closed circulation at the surface.  Chantal exhibited the
  cloud pattern of a fairly well-defined tropical cyclone, but the rapid
  translational speed had led to the storm's being unable to maintain its
  surface circulation--if it had ever existed at all.  The NHC Monthly
  Summary suggests that possibly Chantal was not a bonafide tropical
  storm on 16 August.  It will be interesting to see how this phase of
  Chantal's life is handled when the final storm report becomes available
  later.    A special advisory was issued at 07/0000 UTC downgrading 
  Chantal to a tropical wave about 100 nm west of Barbados.

     Even as a tropical wave, the system produced winds to tropical storm
  force on Martinique as it passed through the Windward Island chain.
  By the morning of the 17th convection had greatly increased and the
  system exhibited a very impressive cloud pattern.  After looking very
  hard, a reconnaissance plane found a small 1010-mb center about
  330 nm south-southeast of San Juan, Puerto Rico, so advisories were
  commenced once more on Chantal at 1500 UTC.  The depression was still
  moving rapidly westward at 23 kts; nonetheless, another flight during
  the afternoon found a well-defined center with a pressure of 1006 mb
  and winds strong enough to justify upgrading the system back to
  tropical storm status, so Chantal became a tropical storm once more
  at 2100 UTC with 35-kt winds, located about 250 nm south of San Juan.

     Based on reconnaissance reports during the night, by the morning of
  18 August Chantal's MSW had been increased to 50 kts, but the 1500 UTC
  advisory noted that satellite imagery revealed an exposed LLCC moving
  rapidly to the west-northwest, leaving the mid-level circulation and
  most of the convection behind.  Reconnaissance planes, however, had
  found winds exceeding hurricane force at flight level (450 m), so in
  spite of the very disorganized appearance, Chantal continued to
  maintain rather strong winds and even intensified some.  By 1200 UTC on
  19 August, the storm had reached an initial peak intensity of 60 kts at
  a point about 215 nm southwest of Kingston, Jamaica, even though all
  the strong winds were in the northeastern quadrant.   To the south of
  the broad and ill-defined center only light and variable winds were
  found.  (More on this particular reconnaissance flight below.)

     Chantal's forward motion slowed some on the 19th and 20th, but the
  benefits of the slower translational speed were offset by some shear
  from an upper-level trough over the western Caribbean.  The storm
  struggled to survive as a tropical cyclone, but the intense convection
  helped to maintain fairly strong winds and the MSW was never lowered
  below 55 kts during this period.  As Chantal approached the Yucatan
  Peninsula on 20 August, the shear began to relax and the storm
  responded by developing a better-defined center and intensifying right
  up to the moment of landfall.  The MSW was estimated at 60 kts once
  again as the center made landfall near Chetumal, Mexico.   The 21/1500
  UTC discussion noted that even though the center of Chantal had been
  over land for around 12 hours, the satellite signature was the best
  that it had been during the storm's history.

     Chantal was originally forecast to move west-northwestward across
  the Yucatan Peninsula and emerge into the Bay of Campeche with a chance
  of re-intensifying.  However, by 2100 UTC on the 21st convection had
  decreased significantly and most of what was left was over the
  Caribbean well removed from the center.  Chantal was downgraded to a
  30-kt depression; the system, however, was still showing anticyclonic
  outflow.  By 22/0300 UTC convection had continued to diminish and
  the mid-level center had sheared off to the northeast.  Even though
  a reconnaissance flight found 25-35 kt winds at flight level over the
  Bay of Campeche to the north, the low-level center turned to the south-
  west and began to dissipate over southeastern Mexico.  The final
  advisory on Tropical Depression Chantal, at 22/1200 UTC, placed the
  dissipating center near Villahermosa, Mexico.

  C. Meteorological Aspects

     Reconnaissance flights into Chantal on 18 and 19 August reported
  some unusual happenings.   A flight during the evening of the 17th
  reported 58-kt winds at 450 m north of the center with a central
  pressure of 1004 mb.   Convection was more concentrated but the crew
  reported that the circulation at flight level was not well-defined.  A
  reconnaissance mission around 18/0600 UTC reported winds to 73 kts at
  450 m, but this was adjudged to likely be due to mesoscale convective
  effects.  During the morning of the 18th satellite imagery revealed an
  exposed LLCC moving rapidly west-northwestward away from the mid-level
  circulation and convection; nonetheless, a reconnaissance plane fixed
  another weak center to the south with flight-level winds of 67 kts.
  Chantal had become disorganized with an elongated center.   During the
  afternoon it became apparent that unexpected shear from an upper-level
  trough over the western Caribbean was the culprit that was disrupting
  Chantal's cloud pattern, which consisted of a very tight center of
  low clouds to the west of a strongly-curved band of deep convection.
  Reconnaissance data during the afternoon showed a pressure of 1003 mb
  and 50-60 kt winds in the band of convection.

     The most unusual reconnaissance missions occurred early on the
  morning of 19 August.  The flight around 0600 UTC reported 62-kt winds
  at 450 m in the southeast quadrant with the pressure down to 997 mb--
  a drop of 6 mb since the previous mission.    Satellite intensity
  estimates were running around 45-55 kts, but the center was fixed on
  the western edge of the deep convection, whereas the reconnaissance
  crew placed the center farther back into the deep convection.  Thus,
  it appeared that Chantal's forward motion had slowed dramatically and
  that the storm was forming an eye and possibly embarking on a spell
  of rapid intensification.

     The 1200 UTC reconnaissance was most extraordinary.  Rich Henning
  was present on that flight and has personally related to me some of
  the surprises they found.  They flew into Chantal expecting to find a
  hurricane but barely found a closed circulation.  Because of some deep
  convection with very intense lightning and likely strong updrafts and
  downdrafts, the aircraft entered the storm at a higher altitude (around
  1500 m) than the earlier flights.   The plane approached the center
  from the northeast and 82-kt winds were observed in that quadrant.
  However, no eye was found, and they eventually broke out of the
  convection into a large, broad area of light and variable winds well
  southwest of the main area of deep convection.  The lowest pressure
  found was 1004 mb.  Rich stated that it was with great difficulty that
  they found enough of a circulation to justify a vortex fix.  Only very
  light and variable winds could be found to the south of the broad
  center.  Two subsequent flights through the northeast quadrant found
  peak winds of 72 kts and 62 kts, respectively.   What seems to have
  happened was that during the night Chantal had made an attempt at
  forming a tight vortex, but that it failed to develop further and the
  storm was weakening by the time the 1200 UTC mission reached the area.

     Chantal remained in a disorganized state until the morning of the
  20th when it began to show somewhat better organization.   A flight
  into the storm around 0000 UTC found the storm still poorly-organized
  with the LLCC about 100 nm to the west of the nearest deep convection.
  The reconnaissance crew reported flight-level winds of 69 kts, but the
  dropsonde released at that point measured surface winds of only 38 kts.
  Chantal was not effectively transporting momentum to the surface.
  Reconnaissance fixes were consistently to the south of the low-level
  cloud swirl, which implied that the surface wind center lay to the
  south of the low-level vorticity center.   The next reconnaissance
  mission into the storm at 0532 UTC found a better-defined circulation,
  and satellite imagery indicated that a large thunderstorm cluster had
  developed over or near the LLCC.  The peak flight-level winds found
  were 61 kts at 850 mb at 0552 UTC.  By afternoon Chantal's appearance
  was still better--satellite imagery portrayed a comma-shaped cloud
  pattern with the center near the edge of the dense overcast, the
  southern portion of the circulation had become distinct, the strongest
  winds in the northeast quadrant were nearer the center, and water vapor
  loops suggested that the shear was decreasing.

     Reports from USAF reconnaissance flights and a NOAA P-3 research
  mission revealed that Chantal continued to strengthen right up to the
  time of landfall near Chetumal.  A dropsonde in deep convection north-
  east of the center at 20/2144 UTC measured 58-kt winds at the surface
  and the peak flight-level wind was 71 kts--these values corresponding
  to a surface MSW of 60 kts.  Right at landfall there was a burst of
  deep convection very close to the center.   The NHC advisory at 0900
  UTC stated that surface observations from Chetumal and Belize, along
  with radar reports, indicated that Chantal had either stalled or had
  developed a new center farther south and east of the previous advisory
  position.  Radar data at 0800 UTC indicated that an eyewall was trying
  to close off between San Pedro and Corozal.     As noted earlier,
  Chantal's satellite signature continued to improve for a while after
  the center had moved inland.

  D. Damage and Casualties

     No fatalities were associated with Chantal while it was a tropical
  cyclone, although two deaths were reported in Trinidad due to lightning
  associated with the passage of the tropical wave through the Lesser
  Antilles.  Damage in Belize was estimated at $10-15 million, and there
  were no reports of significant damage in Mexico.

                        Tropical Storm Dean  (TC-05)
                                22 - 29 August

  A. Origins

     Unlike its two predecessors, Dean's formation doesn't seem to be
  directly related to a wave of African origin.  Based upon information
  taken from TPC's Tropical Weather Discussions, the progenitor of Dean
  seems to be a disturbance initially located on the ITCZ that detached
  itself and headed west-northwestward.  The disturbance was first
  mentioned at 1800 UTC on 18 August when located near 13.0N, 35.0W,
  with an associated 1015-mb LOW.  By the early morning of the 19th the
  wave was located about 1400 nm east of the Windward Islands.  It was
  not too well-organized but was showing signs of increased convective
  organization.   On the 20th the disturbance had moved to a position
  about 650 nm east of the Windwards and shower activity was still

     Convection increased on the 21st when the wave was located about
  450 nm east of the Lesser Antilles.   A TWO noted that upper-level
  winds were not favorable for rapid development but some slow
  organization was possible.   A reconnaissance flight by the Hurricane
  Hunters during the afternoon of 21 August was unable to locate a
  closed LLCC.  The wave was moving rather rapidly west-northwestward
  at 20 kts; it was well-organized but upper-level winds were inhibiting
  development.  On the morning of the 22nd the wave appeared much better
  organized based on surface, radar and satellite observations.  The
  system was moving west-northwestward at 18-22 kts through the northern
  Lesser Antilles and upper-level winds were becoming a little more
  favorable for strengthening.

     The next reconnaissance mission into the disturbance on the after-
  noon of 22 August found a surprise--a small 1010-mb center located
  north of the Virgin Islands with 65-kt winds at 300 m over the north-
  east quadrant.  Therefore, advisories were initiated immediately on
  Tropical Storm Dean with 50-kt winds.  Dean's center was located at
  the time about 115 nm east-southeast of San Juan and moving west-
  northwestward at 22 kts.  The center was exposed on the western edge
  of the deep convection, and the NHC discussion noted that some of the
  observed strong winds were likely due to the rapid translational 
  speed.  On the last pass of the reconnaissance plane through the 
  storm, a 1009-mb center was fixed and maximum flight-level winds were
  63 kts.   The center was exposed at the northern end of a convective 
  band trailing southward across the Virgin Islands.

  B. Track and Intensity History

     Exactly what factors led to the sudden intensification of the
  tropical wave into a fairly strong tropical storm aren't clear, but
  the intensification trend certainly did not continue.  The 23/0300
  UTC advisory noted that a recent QuikScat pass had showed an open
  wave, leading to the possibility that Dean no longer possessed a
  closed circulation.  The small storm had moved into a region of
  fairly strong vertical shear and found it to be more than it could
  withstand.  Nighttime infrared imagery suggested the possibility of
  multiple circulation centers, and a reconnaissance flight during the
  morning of the 23rd was unable to locate a closed surface circulation.
  The plane found a minimum pressure of 1013-1014 mb with maximum 
  flight-level winds of 42 kts east of the remnant low-cloud swirl.  So
  a final advisory on Dean was issued at 1500 UTC placing the 
  dissipating center about 325 nm northwest of San Juan.

     The remains of former Tropical Storm Dean moved northward ahead
  of a slow-moving frontal boundary lurking off the U.S. East Coast.
  By the morning of the 24th satellite images indicated that Dean's
  remnants had become better organized with a possible broad surface
  circulation forming about 350 nm west-southwest of Bermuda.  A
  reconnaissance mission into the disturbance during the afternoon
  found a broad 1011-mb LOW with a weak wind field about 300 nm west-
  southwest of Bermuda, moving north-northeastward at around 13-18 kts.
  The weak LOW interacted with a non-tropical trough to its west, and by
  1200 UTC on the 25th the two systems had merged to form a hybrid
  depression roughly 150 nm northwest of Bermuda.

     During the 26th ships began to report gale-force winds and
  convection slowly increased around the center.   Early on 27 August
  a ship with call sign WGMJ reported southerly winds of 55 kts with
  a SLP of 1004 mb near the center of the cloud mass.   Since the
  system had intensified and taken on a more tropical appearance once
  more, advisories were re-initiated on Tropical Storm Dean at 27/0900
  UTC.  The storm was centered at 0600 UTC about 425 nm south-southeast
  of Halifax, Nova Scotia, and was moving northeastward at 16 kts.
  The cyclone subsequently attempted to form a banding eye, and the
  MSW was increased to 60 kts at 1800 UTC when Dean was centered about
  475 nm southwest of Cape Race, Newfoundland.   Convection began to
  decrease early on the 28th with the center defined by a swirl of low-
  to mid-level clouds east of the primary convection.  At 0500 UTC a
  Canadian buoy (44141) reported a pressure of 1004.3 mb and 5.5 m seas
  55 nm southeast of the center.

     As Dean began to move over colder SSTs of 22 C or less, cool and 
  dry air began to work into the system, the pressure fields began to
  broaden, and the storm began to rapidly weaken and lose tropical
  characteristics.  The final NHC advisory was issued at 1500 UTC on
  the 28th and placed Dean about 200 nm south of Cape Race.  The storm
  was fast becoming extratropical as it accelerated to the east-
  northeast.   David Roth considers the system to have re-assumed a sort
  of hybrid/subtropical appearance for a day or so as there was limited
  convection southwest and north of the center.    Transition to an
  extratropical cyclone was complete by 30/0000 UTC as all convection
  had disappeared and the system had become linked to a baroclinic band
  as seen in satellite imagery.  The final position in David's track
  places the extratropical gale over 500 nm east-northeast of Cape Race.

  C. Meteorological Aspects

     Since Dean had such a short life as a tropical cyclone, including
  both phases, all the information received by the author from surface
  observations and reconnaissance missions has been incorporated into
  the above paragraphs detailing the storm's track and history.

  D. Damage and Casualties

     Winds to tropical storm force were reported in the U. S. Virgin
  Islands, and there was some damage due to flooding in Puerto Rico.
  Total damage is estimated at about $2 million.    No deaths were
  attributed to Tropical Storm Dean.


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

  Activity for August:  1 tropical depression
                        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.   A special thanks
  to John Wallace of San Antonio, Texas, for writing the summary on
  Hurricane Flossie.

              Northeast Pacific Tropical Activity for August

     The month of August on the average sees about four named storms
  develop in the Northeast Pacific basin.  Two of these will reach
  hurricane intensity with one becoming a major hurricane (Category 3+
  on the Saffir/Simpson scale).  August, 2001, was definitely a quieter
  than normal month in this basin.  Only one tropical storm developed,
  Flossie, although it did become a Category 2 hurricane.

     In addition to Hurricane Flossie, one short-lived tropical
  depression was tracked in the Eastern Pacific during August.  This
  depression can be traced back to a tropical wave which left the west
  African coast around 7 August.  The wave made its way westward across
  the Atlantic and Caribbean Sea, reaching the Eastern Pacific by the
  17th.  Once in the Pacific the disturbance continued moving rather
  rapidly westward, and by 21 August had reached the vicinity of 132W,
  or about 1300 nm east-southeast of the Hawaiian Islands, and was
  showing some signs of increased organization.   The next day a good
  low-level circulation was evident in the low clouds with ragged deep
  convection near the center, so advisories were initiated on Tropical
  Depression 06E, located about 1100 nm east of the Hawaiian Islands or
  about 1500 nm west-southwest of Cabo San Lucas on the tip of the Baja
  California Peninsula.

     However, even as the depression was upgraded it was crossing the
  25 C isotherm, so little further strengthening was forecast.  The weak
  cyclone moved slowly north-northwestward and almost immediately ran
  into some southerly shear due to an upper-level trough lying to its
  west.   By 1200 UTC on 23 August the depression consisted mainly of
  a swirl of low clouds with a few showers to the north and northeast of
  the center.  Some intermittent bursts of convection were seen during
  the day as the trough, which although was the source of the shear,
  provided some diffluence over the system.    By 24/0000 UTC the
  depression was beginning to dissipate with the center becoming
  elongated, resembling a shear axis.  With strong shear still above
  the system and 24 C waters below, regeneration was deemed unlikely.
  The final advisory on TD-06E was issued at 0300 UTC and placed the
  disspiating center only about 200 nm north-northwest of its point of

                      Hurricane Flossie  (TC-07E)
                        26 August - 2 September

  A. Origins

     The origin of Hurricane Flossie does not appear to be related to a
  tropical wave, but to a tropical LOW that was first noted off the
  Mexican coast on 24 August.   The LOW tracked west-northwestward and
  steadily organized.  By 0900 UTC on 26 August, its organization had
  increased enough to warrant its upgrade to Tropical Depression Seven-E
  approximately 175 nm south of Cabo San Lucas.  The depression tracked
  roughly west-northwestward, south of a 500-mb ridge.  It continued to
  strengthen, and was upgraded to Tropical Storm Flossie at 2100 UTC on
  the 26th, located 160 nm southwest of Cabo San Lucas.

  B. Track and Intensity History

     Flossie intensified on the 27th under increasingly favorable
  conditions while its track bent more toward the west; this development
  spared it from cooler SSTs to its north.  Satellite data supported its
  upgrade to Hurricane Flossie at 2100 UTC on 27 August about 310 nm
  west-southwest of Cabo San Lucas; this made it the first Pacific
  hurricane in over a month.  Flossie made an unusual west-southwestward
  turn upon its upgrade, as the ridge to its north moved westward with
  it.  On the 28th, Flossie tracked slowly southwestward, due to the
  strong ridge that was then to its northwest.   The hurricane briefly
  became quasi-stationary late on the 28th; the ridge to its north
  weakened while a cyclonic shear axis to its southwest exerted a more
  northerly influence on the track.  Another ridge southeast of Flossie
  placed the system in a weak col; even so, a slow northwestward track
  commenced late on the 28th as the northern ridge weakened.  Flossie
  underwent a quick burst of intensification the following day, and
  peaked at 2100 UTC on 29 August some 445 nm west of Cabo San Lucas.
  At this time, it had an estimated MSW of 90 kts and a 972-mb CP.
  Flossie slowly weakened thereafter as it tracked over cooler SSTs.

     Flossie dropped below hurricane strength on the 31st; late that day
  its track turned to the north, then northwestward on the 1st as a 
  shortwave trough "picked up" the system.    The storm weakened to a
  depression at 1500 UTC on the 1st, due both to increased vertical shear
  and unfavorable SSTs.   The final advisory on Tropical Depression
  Flossie was issued at 0300 UTC on 2 September, placing the dissipating
  center about 585 nm west-northwest of Cabo San Lucas, or roughly
  200 nm west-southwest of Punta Eugenia.   Moisture from Flossie's
  remnants spread across Baja California and the American Southwest,
  advected northeastward by upper-level winds.

  C. Meteorological Aspects

     Flossie was notable for both being the first storm after an 
  unusually long break in Northeast Pacific activity, and for being
  an amazingly compact tropical cyclone.  Upon its upgrade to a named
  storm, tropical storm-force winds extended only 50 nm from the center;
  the radii were never greater than 75 nm throughout its life.  At its
  peak, hurricane-force wind radii were only 15 nm, as compared to
  the 15 nm-diameter of the eye itself.  It has been hypothesized that
  Flossie's small size was the key to its surprising peak intensity,
  given its proximity to cool water and stable air; if it had been
  larger, it might have entrained more dry air or caused more upwelling.

  D. Damage and Casualties
     No casualties are known, and no watches or warnings were required.


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

  Activity for August:  3 tropical depressions **
                        3 tropical storms
                        2 typhoons
                        1 super typhoon

  ** - One of these was treated as a tropical depression only by PAGASA.
       Another was classified as a tropical depression by JMA, NMCC and
       Taiwan, but not by JTWC.    The third was treated as a tropical
       depression by JMA and briefly by JTWC; Roger Edson, however,
       believes this system reached tropical storm intensity.

  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.

     Also, some information based upon warnings issued by the National
  Meteorological Center of China (NMCC) and the Hong Kong Observatory
  (HKO) is included.  The tracks from these agencies were sent to me
  by Huang Chunliang of Fuzhou City, China.  Finally, Roger Edson of
  the University of Guam sent me his versions of tracks for Tropical
  Depression 15W and Tropical Depression Jolina.   A special thanks to
  these gentlemen for the information they sent.

     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 August

     A very active August followed on the heels of an active July.  Six
  named storms developed--one more than in July, but only three reached
  typhoon intensity--one less than in July.  However, one of the August
  typhoons, Wutip, became the season's first super typhoon as winds
  climbed to 130 kts.    (All these typhoon statistics are based upon
  JTWC's classifications.)   None of the typhoons made landfall while
  at typhoon strength, although Typhoon Man-yi passed through the
  northernmost Marianas Islands.  Typhoon Pabuk, after weakening to
  tropical storm strength, made landfall in south-central Honshu and
  skimmed eastward along the coast, passing very near Tokyo.    Weak
  tropical storms Usagi and Fitow made landfall in Vietnam and southern
  China, respectively.   Reports on all of the named cyclones follow.

     There were three systems (possibly four) which were classified as
  tropical depressions by one or more of the several TCWCs in the NWP
  basin.  Following are brief synopses of these systems.

     Tropical Depression(s) of 2-3 and 6-8 August - A low-pressure area
  moved quickly westward from a position several hundred miles southeast
  of Okinawa.   At 02/0000 UTC JMA referred to the system in their High
  Seas Warning and Summary bulletin as a weak tropical depression located
  about 525 nm southeast of Okinawa.  By 1200 UTC the system had moved to
  a position about 300 nm south-southeast of Okinawa and JMA assessed the
  maximum winds to be 30 kts.  The depression continued moving rapidly
  westward and by 0600 UTC on 3 August was located 150 nm southeast of
  Taipei, Taiwan.  The system was also showing signs of weakening.  It
  reached the coast of China near Fuzhou City around 1500 UTC the same
  day.  JTWC did not classify this system as a tropical depression nor
  were any TCFA's issued; however, in addition to JMA, both NMCC and
  Taiwan's Central Weather Bureau treated the LOW as a depression.

     After moving inland the system turned more to the north, then east-
  ward after reaching Anhui Province.  The depression's remnants passed
  near Shanghai on 5-6 August, triggering a 14-hour period of heavy
  rains which began around 1600 locally on the 5th.   By 0800 (local)
  the next morning, the city had averaged 150 mm of rain with the
  Huangpu district netting 289 mm and several other districts, including
  Xuhui and Luwan, exceeding 220 mm.  The rain was reported to be the
  heaviest that the Shanghai area had seen in ten years.  Over 30,000
  residential houses were inundated.  Additionally, the system triggered
  a tornado which struck Sunqiao, Shanghai.

     At 0600 UTC on 6 August, JMA noted the existence of a weak tropical
  depression in the southern Yellow Sea about 100 nm north-northeast of
  Shanghai.  JTWC also mentioned the disturbance in their STWOs, giving
  it a fair potential for development.  The system, however, did not
  strengthen further, and after remaining quasi-stationary for a day or
  so, began to move off to the northeast and crossed the Korean Peninsula
  as a weak LOW.  There is no conclusive evidence that this second system
  was a redevelopment of the depression of 2-3 August, but it does seem
  likely that they were related.   (A special thanks to Huang Chunliang
  for sending me the information on the Shanghai rainfall event.)

     Tropical Depression Jolina - PAGASA issued bulletins on a South
  China Sea system on 16-19 August which was named Jolina.  During this
  period the depression remained basically quasi-stationary west of
  Luzon.  To my knowledge no other warning centers issued any bulletins
  on this system.     After I had posted the August tropical cyclone
  tracks, I received some information from Roger Edson on circulations
  in the South China Sea.  Roger wrote: "Active monsoon trough during
  this period with axis around 16N.  Several circulations developed
  along the trough (at least one on the 13th and one on the 15th).
  Finally I could follow the third circulation from the 17th (Jolina)
  with good scatterometer and microwave data from this point.  Nice
  exposed circulation on the 21st in the mid-South China Sea."  Roger
  also sent his version of a track for Jolina.   I have incorporated
  Roger's tracking information into the track for Jolina and have
  re-sent the August tracks file to the gentlemen who archive the
  summaries and tracks.

     Tropical Depression 15W - At 1200 UTC on 24 August, JMA noted in
  a High Seas Bulletin the existence of a weak tropical depression
  about 350 nm northwest of Wake Island.  This system subsequently
  followed a long trajectory which took it generally northwestward to
  just east of the northernmost Japanese island of Hokkaido.  It then
  recurved to the north-northeast and passed through the southern Kuril
  Islands as it became extratropical.  JMA estimated that 30-kt winds
  were associated with the depression on 25 August, but for the remainder
  of its life it was relegated to the Summary portion of the bulletins,
  implying 25-kt winds.  At 1800 UTC on the 24th JTWC issued the first
  of three warnings on the depression, numbering it TD-15W.  The MSW
  was estimated at 30 kts and the system was forecast to strengthen to
  a tropical storm.  However, the third warning (25/0600 UTC) indicated
  that the system was merging with a frontal boundary and dissipating.

     However, Roger Edson sent me his version of a track for this system
  and he feels that it reached tropical storm intensity.    Roger does
  note that it was very difficult to follow, especially at first, as
  it was very small and mostly embedded in the monsoon trough.  Roger
  feels that JTWC "lost" the system as it accelerated northward along
  the west side of the monsoon trough, with this beginning to happen
  overnight when there was no visible imagery.  Roger's track for the
  system follows JMA's track fairly closely and starts the depression
  at 23/1800 UTC with tropical storm intensity being reached at 1200 UTC
  on the 24th.    Roger estimates that a peak intensity of 50 kts was
  reached at 0600 UTC on 26 August when the system was located several
  hundred miles east-southeast of Tokyo.   It is interesting to note
  that on 26 and 27 August, SAB was assigning CI numbers of 2.5 (35 kts)
  which lends support to the idea that the system did reach tropical
  storm intensity.  In addition to the JMA/JTWC track for TD-15W, the
  cyclone tracks file for August contains Roger Edson's track for this
  system with several of his comments included in the remarks column.

                    Typhoon Man-yi  (TC-12W / TY 0109)
                               1 - 11 August

  Man-yi: contributed by Hong Kong, was originally the name of a strait.
          With the construction of a dam, that part of the sea has become
          a reservoir.

  A. Origins

     A STWO issued by JTWC at 0200 UTC on 31 July noted that an area of
  convection was developing approximately 150 nm north of Pohnpei.  
  Animated infrared imagery showed persistent deep convection and 
  cyclonic turning whereas animated visible imagery and synoptic data did
  not support the existence of a closed LLCC.  A 200-mb analysis showed 
  weak ridging over the disturbance.     A few hours later microwave 
  imagery depicted improving organization with weak low-level cloud lines
  indicative of a developing LLCC; the development potential was upgraded
  to fair.

     A TCFA was issued at 0100 UTC on 1 August.  Convective organization
  was improving and a recent SSM/I pass had revealed a possible banding
  feature south of the LLCC.  The system exhibited good outflow to the
  south and east.  The STWO issued at 0600 UTC noted that there had been
  a new flare-up of deep convection near the center during the previous
  few hours.  An upper-level LOW to the north was enhancing outflow, and
  water vapor imagery and a 200-mb analysis depicted organizing 
  equatorial outflow to the south of the center.  JTWC issued the first
  warning on TD-12W at 01/1800 UTC with the center located about 200 nm
  north-northeast of Chuuk, moving west-northwestward at 8 kts.

     On the second warning--issued at 02/0000 UTC---JTWC upgraded the
  depression to a tropical storm based on satellite CI estimates of 30
  and 35 kts.  Infrared satellite imagery depicted rapidly improving
  organization and banding over the past few hours.  The storm continued
  moving to the northwest and steadily intensified.  The MSW was upped
  to 45 kts at 0600 UTC based on CI estimates of 35 and 45 kts; satellite
  imagery revealed a developing 130-nm diameter CDO feature with cold
  cloud tops to -83 C.  NMCC upgraded the system to a tropical storm
  at 0600 UTC, and JMA followed suit at 1200 UTC, naming the cyclone
  Tropical Storm Man-yi.  At the time, Man-yi was centered approximately
  300 nm north-northwest of Chuuk or about 325 nm east-southeast of Guam.

  B. Track and Intensity History

     Initially, Tropical Storm Man-yi was steered northwestward or north-
  northwestward at a fairly good clip of around 15-16 kts by a low- to
  mid-level subtropical ridge to the storm's northeast.    The cyclone
  steadily intensified, reaching typhoon intensity at 0600 UTC on the
  3rd (per JTWC) when located about 125 nm east-northeast of Saipan.
  Winds had reached 95 kts by 04/0000 UTC--enhanced infrared imagery
  depicted deep convection developing in the eyewall.  JTWC upped the
  MSW to 110 kts at 0600 UTC, noting that Man-yi was a symmetric system
  with a round eye 6 nm in diameter.   Typhoon Man-yi reached an initial
  peak intensity of 115 kts at 1200 UTC on the 4th when satellite imagery
  revealed a well-defined primary banding feature wrapping in toward the
  vortex center from the southwest.    Gales extended outward 145 nm
  northeast of the center and 60 nm to the southwest, while storm-force
  winds reached outward 75 nm to the northeast and 35 nm to the south-
  west.  Man-yi was centered about 200 nm southeast of Iwo Jima at the

     As Man-yi continued north-northwestward it moved into a weakness in
  the subtropical ridge and recurved to the northeast on the 5th.  The
  storm reached the westernmost point of its track at 05/0000 UTC when it
  was centered approximately 115 nm east of Iwo Jima.   After recurving
  to the northeast, Man-yi initially weakened some with winds dropping to
  95 kts by 06/0000 UTC.  This weakening was likely due to some shear
  plus an eyewall replacement cycle.   A 04/1102 UTC SSM/I pass depicted
  a collapsed eyewall in the eastern quadrant with an associated banding
  feature over the southwest quadrant; winds were lowered to 110 kts
  at 04/1200 UTC.   At 06/0000 UTC water vapor imagery indicated less
  vertical shear over the typhoon with an outflow channel to the north.
  Man-yi responded by re-intensifying to 115 kts by 1200 UTC on the 6th.
  By this time the system had developed pronounced dual outflow channels,
  and the gale- and storm-force wind radii were more symmetric than at
  the earlier peak.  Gales extended outward 110 nm northeast of the
  center and 90 nm to the southwest, while 50-kt winds reached out an
  estimated 60 nm to the northeast and 50 nm to the southwest.  Man-yi's
  large 45-nm round eye was centered about 250 nm northeast of Iwo Jima
  at this time.

     As Typhoon Man-yi continued on toward the northeast, gradually
  curving back more to the north-northeast, it began to slowly weaken.
  The diameter of the eye also continued to increase, reaching 65 nm
  at 07/0000 UTC.   The storm became one of the so-called truck-tire,
  or annular, typhoons: storms which develop a very large eye in
  proportion to the CDO and look like huge doughnuts or truck tires.
  Winds were down to 95 kts by 1800 UTC on 7 August and the storm was
  beginning to exhibit signs of extratropical transition.  By the 8th
  Man-yi was north of the ridge axis and still moving northeastward,
  but a mid-level HIGH was forecast to move out of the Sea of Okhotsk
  and cause the storm to take a more northward track.  This forecast
  verified--by 08/1200 UTC Man-yi was moving northward at 17 kts from
  a position about 550 nm east of Tokyo.  Peak winds were down to
  minimal typhoon intensity and cold air was wrapping into the
  circulation from the north and west with no eyewall visible any

     JTWC declared Man-yi to be extratropical at 1800 UTC on the 8th and
  issued their final warning, placing the storm about 500 nm south of the
  Kuril Islands.  JMA continued to carry Man-yi as a tropical storm until
  1800 UTC on 9 August when it was well east of Hokkaido.  The extra-
  tropical remnants of Man-yi continued trekking northeastward parallel 
  to the Kuril Island chain.  By 11/0000 UTC the system had weakened to a
  20-kt LOW southeast of the tip of the Kamchatka Peninsula.

     In summary, Typhoon Man-yi reached an estimated peak intensity (per
  JTWC) of 115 kts on three occasions: at 1200 and 1800 UTC on 4 August,
  at 0600 UTC on 5 August, and at 1200 and 1800 UTC on 6 August.  The
  minimum central pressure assigned by JMA was 945 mb at 0000 and 0600
  UTC on 5 August.

  C. Meteorological Aspects

     The most noteworthy event of Man-yi's history, meteorologically
  speaking, was the evolution of its eye from a pinhole eye only 6 nm
  in diameter on the 4th to a huge 65-nm diameter eye on the 7th.  An
  eyewall replacement cycle seems to have been ongoing during part of
  this period.  The JTWC warning issued at 05/0600 UTC noted that an
  apparent eyewall replacement cycle was beginning with visible imagery
  depicting a developing convective ring 33 nm in diameter.  Six hours
  later the eyewall had collapsed in the eastern quadrant.  The 1800
  UTC warning noted that a TRMM pass at 1315 UTC had depicted a nearly
  concentric rainband outside a large eye feature.  The diameter of the
  eye had grown to 45 nm at 06/0600 UTC and to 65 nm at 0000 UTC on the
  7th.  According to Mark Lander, once a tropical cyclone reaches this
  "annular" stage, the large eye condition tends to be stable.  Also,
  Mark noted that this particular type of tropical cyclone evolution is
  fairly common in the region of the Ryukyu Islands--many typhoons with
  very large eyes have crossed Okinawa.  Typhoon Man-yi was located not
  all that far from the primary "truck-tire" region.

  D. Comparisons Between JTWC and Other Centers

     Center position coordinates were in excellent agreement between the
  various warning agencies throughout the life of Man-yi.  As usual, the
  intensity estimates between JTWC and JMA agreed fairly well during the
  earlier stages of the cyclone and during the weakening phase.  JMA's
  peak 10-min mean sustained wind estimate was 80 kts from 04/1200 UTC
  through 06/0000 UTC, whereas, as noted above, JTWC's peak 1-min avg
  MSW estimate was 115 kts.   JMA's reported intensities also do not show
  the double peak as indicated by JTWC:  JMA's intensity estimates
  remained at 75 kts during the storm's second intensification phase
  reported by JTWC.   NMCC's peak 10-min mean MSW was 100 kts from
  04/1200 through 05/1200 UTC.  This agrees very closely with JTWC's
  peak 1-min avg MSW of 115 kts; however, neither do NMCC's intensities
  reflect the second peak, remaining at 80 kts through this period.

  E. Damage and Casualties

     Typhoon Man-yi passed through the northernmost Marianas Islands on
  3 and 4 August during the time at which it was becoming a rather
  intense typhoon; however, I have received no reports of any damage or
  casualties that might have resulted.  If any become available later,
  they will be reported in a future summary.

                 Tropical Storm Usagi  (TC-13W / TS 0110)
                               8 - 11 August

  Usagi: contributed by Japan, is the Japanese word for rabbit

  A. Origins

     A STWO issued by JTWC at 0600 UTC on 8 August mentioned that an area
  of convection had developed and persisted in the South China Sea just
  west of Luzon.  Animated visible imagery depicted organized convection
  associated with a possible LLCC in a region of weak to moderate
  vertical shear.  At 1800 UTC the disturbance was located approximately
  330 nm south of Hong Kong with animated enhanced infrared imagery
  showing new deep convection developing west of the LLCC.  JTWC upgraded
  the development potential to fair at this time.

     The first warning on TD-13W was issued at 09/0000 UTC with the 
  center located about 300 nm south of Hong Kong.  The MSW was estimated
  at 25 kts and the depression was moving west at 12 kts.  (NOTE: The
  JMV file, a sort of working Best Track, indicates that JTWC retro-
  actively considers the system to have become a depression at 0600 UTC
  on 8 August about 400 nm south-southeast of Hong Kong.)  The second
  warning (at 09/0600 UTC) noted that the center of TD-13W was fully-
  exposed about 30 nm east of the deep convection.  Six hours later the
  center was still exposed but a weak banding feature was attempting to
  wrap into the vortex from the southwest.  Upper-level easterlies of 30
  to 40 kts over the region were continuing to hamper further development
  of the depression.

     Organization had improved slightly by 1800 UTC and JTWC increased
  the MSW to 30 kts.  A SSM/I pass at 09/2240 UTC depicted a partially-
  exposed center with deep convection still sheared to the west; CI
  estimates had risen to 30 and 35 kts around this time.  By 0600 UTC
  on the 10th animated visible imagery indicated that the LLCC was
  situated beneath the extreme northern edge of the deep convection.
  JTWC relocated the center to a position about 70 nm west of the 
  previous warning position, just off the Vietnamese coast south-
  southwest of Hainan Dao.  CI estimates were 35 kts and JTWC, NMCC
  and JMA all upgraded the system to a tropical storm with JMA assigning
  the name Usagi.   Six hours later HKO had also upgraded Usagi to a
  40-kt tropical storm.

  B. Track and Intensity History

     Usagi's career as a tropical storm was quite short-lived, however.
  The storm reached its peak intensity of 40 kts (per JTWC) at 1200 UTC
  on the 10th when it was located about 80 nm east of the Vietnamese
  coast and moving westward at 11 kts.  Enhanced infrared imagery showed
  a primary banding feature wrapping in toward the center from the south-
  west.   By 1800 UTC the center had moved inland about 155 nm south of
  Hanoi and was weakening, so JTWC issued their final warning with Usagi
  continuing to move farther inland at 20 kts.   Tropical Storm Usagi
  tracked westward throughout its life along a monsoon trough south of a
  weakening low- to mid-level ridge.  There were some synoptic reports
  received of winds to 35 kts as the weak tropical storm made landfall.

  C. Comparisons Between JTWC and Other Centers

     Center position coordinates were in good agreement between the
  several warning centers throughout the life of Usagi despite the fact
  that the system remained weak.  JMA's maximum 10-min avg MSW was
  35 kts, which represents excellent agreement with JTWC's peak 1-min avg
  MSW of 40 kts.  HKO and NMCC, however, reported a slightly stronger
  system with peak 10-min mean winds of 40 and 45 kts, respectively.

  D. Damage and Casualties

     I have been unable to locate any reports of damage or casualties
  resulting from the landfall of Tropical Storm Usagi in Vietnam.  There
  was flooding reported in that country during the month of August, but
  I have found no press reports which link the flooding with Usagi.

                     Typhoon Pabuk  (TC-14W / TY 0111)
                               14 - 24 August

  Pabuk: contributed by Laos, is the name of a large freshwater fish
         that lives in the Mekong River

  A. Origins

     JTWC issued a special STWO at 2100 UTC on 13 August for an area of
  convection about 130 nm north-northwest of Saipan which had developed
  rapidly over the previous 6-12 hours.    Animated infrared satellite
  imagery depicted rapidly improving organization with a convective band
  developing south and east of a LLCC.  Synoptic data indicated that 
  the LLCC was located within a broad monsoon depression with 20-kt
  westerly winds south of the center and 25-30 kt winds east of the
  LLCC associated with some deep convection.  Water vapor imagery and
  a 200-mb analysis indicated that an anticyclone was developing over
  the disturbance.    Since the disturbance appeared to be rapidly 
  developing and environmental conditions favored further strengthening,
  the development potential was immediately upgraded to good and a TCFA
  was issued shortly afterward.

     The first warning on TD-14W was issued at 14/0000 UTC placing the
  center 180 nm north of Saipan.  CI estimates were 25 and 30 kts, and
  animated water vapor imagery indicated good outflow, particularly on
  the equatorward side.  A 13/2012 UTC QuikScat pass showed a well-
  defined LLCC with extensive near-gale-force gradient westerlies south
  of the center.   JTWC upgraded TD-14W to a tropical storm at 0600 UTC
  with the center located about 210 nm north of Saipan, moving north at
  6 kts.   JMA and NMCC upgraded the cyclone to a tropical storm six
  hours later with JMA assigning the name Pabuk.

  B. Track and Intensity History

     Initially located in a region of weak steering between mid-level
  ridges to the north-northwest and east, Tropical Storm Pabuk moved
  slowly northward through the northernmost Marianas as a minimal
  tropical storm.  At 14/1200 UTC the storm was relocated farther to
  the west along the western edge of the deep convection.  Animated
  infrared imagery depicted deep convective bands south and east of
  the LLCC while animated multi-spectral imagery indicated that a
  broad circulation had not fully consolidated in the monsoon trough.
  A 14/0841 UTC QuikScat pass showed a LLCC with troughing to the west
  along the monsoonal axis.   Water vapor imagery depicted good outflow
  equatorward of the center with strong upper-level westerlies to the
  north.  At 15/0000 UTC the center was relocated 47 nm to the west of
  the previous warning position based on the appearance of a partially-
  exposed LLCC.

     The cyclone turned to a west-northwesterly track on 15 August as a
  ridge to the north strengthened.  By 1200 UTC water vapor imagery and
  a 200-mb analysis indicated good outflow with the presence of a weak
  anticyclone aloft.   Pabuk steadily intensified and reached typhoon
  intensity (per JTWC) at 1800 UTC on the 15th when it was centered about
  425 nm northwest of Saipan.  (NMCC upgraded the storm to a typhoon at
  0600 UTC on 16 August while JMA waited until 1800 UTC to classify Pabuk
  as a typhoon.)     According to JTWC Pabuk reached an initial peak
  intensity of 85 kts at 17/0000 UTC when the storm was centered about
  575 nm northwest of Saipan.   However, the storm began to show signs 
  of weakening and JTWC lowered the MSW to 75 kts at 1200 UTC and to
  70 kts at 1800 UTC.     During this time Pabuk continued to track
  slowly west-northwestward in easterly flow south of the mid-level ridge
  to the north with some weak southerly flow generated by a ridge to the
  east-southeast.  An upper-level shortwave trough over eastern China was
  forecast to move into the East China Sea and develop a weakness in the
  mid-level ridge over western Japan.

     By early on the 18th Pabuk was beginning to show signs of
  strengthening once more.  The JTWC warning at 0600 UTC noted that a
  banding eye feature was visible in satellite imagery, and at 1200 UTC
  animated imagery depicted a developing eyewall with deep convection
  forming in all quadrants.  Eyewall convection had improved by 1800 UTC
  and a 75-nm irregular eye was visible.  Typhoon Pabuk reached its peak
  intensity of 95 kts at 0600 UTC on 19 August.  Pabuk was a large storm,
  sporting an eye 50 nm in diameter with gales covering an area about
  500 nm across; storm-force winds extended outward about 100 nm from the
  center.  The 20/0000 UTC warning noted that the storm exhibited an
  irregular eye 55 nm in diameter with deep convection cycling diurnally.
  Animated water vapor imagery depicted excellent dual-channel outflow.

     On the 19th Pabuk began moving more northwestward toward a
  developing weakness in the ridge to the north, and by 1200 UTC on
  20 August the storm was moving north-northeastward into a weakness
  created by a mid-latitude trough over the Sea of Japan.  Winds were
  down to 80 kts by 1200 UTC; a SSM/I pass had revealed that most of
  the deep convective bands were in the northern semicircle and that the
  eyewall was eroding.   Pabuk began to weaken rather rapidly as it
  approached the southern coast of Japan.   The center of the cyclone
  just reached the coast of Japan on the southern tip of the peninsula
  south of Osaka around 21/1200 UTC with peak winds estimated at 55 kts.
  (JMA's 10-min avg MSW at the time was 60 kts.)  The weakening storm
  turned more to the northeast and later east-northeast, skimming along
  the coast of southern Honshu.  At 22/0600 UTC Pabuk's center passed
  just south of Tokyo and by 1200 UTC was back over the Pacific east of
  Honshu, moving east-northeastward at 19 kts and rapidly losing tropical
  characteristics.  JTWC issued their final warning at 1800 UTC with the
  now-extratropical Pabuk located about 80 nm east-southeast of Misawa,
  Japan, and moving north-northeastward at 24 kts.  The extratropical
  renmants of Pabuk continued moving northeastward and slowly weakened.
  By 24/1200 UTC the former tropical cyclone was a weak LOW in the
  western Bering Sea near the northeastern coast of the Kamchatka

  C. Meteorological Aspects

     At 21/0000 UTC Murotomisaki reported sustained 10-min mean winds
  of 60 kts with an attendant SLP of 976 mb.    At the time of the
  observation, Pabuk's center was about 100 nm south-southeast of the
  station.  Synoptic reports as the weakening cyclone approached and
  moved over coastal Honshu allowed forecasters to keep a good handle on
  the pressure.  Synoptic reports around 21/0600 UTC indicated that the
  CP was around 970 mb.  This had risen to 981 by 22/0000 UTC and to
  988 mb at 1200 UTC after Pabuk had exited Japan and was back over
  Pacific waters.

     Per JTWC's warnings, Pabuk was at its peak intensity of 95 kts from
  19/0600 through 20/0600 UTC.    The minimum CP estimated by JMA was
  955 mb at 17/0600 UTC, but then remained at 960 mb through 1200 UTC
  on the 20th.

     NOTE:  After I had this report on Pabuk essentially written, I
  discovered in my files an e-mail from Julian Heming to Pete Donaldson
  which raises some questions about the intensity of the cyclone early
  in its life.   JTWC initiated warnings on TD-14W at 14/0000 UTC and
  upgraded the depression to a tropical storm on the second warning at
  0600 UTC.  However, according to Julian's e-mail, ship WFLG reported
  winds of 40 kts at 13/1800 UTC, 39 kts at 13/2100 UTC, and a south
  wind of 46 kts at 14/0000 UTC.   The ship's position was well south
  and east of JTWC's estimated center location, and it is possible that
  since Pabuk was developing as (or in) a large monsoon depression, JTWC
  did not consider the gale-force winds to be representative of the
  developing tropical cyclone's intensity.

  D. Comparisons Between JTWC and Other Centers

     Center position coordinates were in fairly good agreement between
  JTWC, NMCC and JMA during the life of Typhoon Pabuk.  As noted above,
  JMA did not upgrade Pabuk to a typhoon until 24 hours after JTWC had
  done so; otherwise, intensity estimates were in fairly good agreement
  between the two warning centers.   During Pabuk's initial peak of
  85 kts, JMA's reported 10-min avg winds were around 70-75 kts, which
  represents very good agreement.  However, JMA's intensity remained at
  70 kts during the time Pabuk reached its peak JTWC intensity of 95 kts.
  The peak MSW (10-min avg) reported by NMCC was 80 kts for a full 3-1/2
  day period, extending from 17/0000 through 20/1200 UTC.

  E. Damage and Casualties

     Pabuk moved through the Northern Marianas as a minimal tropical
  storm early in its career, but I have received no reports of damage
  of casualties from the islands as a result of the storm.  Pabuk was
  responsible for seven deaths in Japan as it swept the southern coast
  of Honshu.  Hundreds of homes were flooded and rail, sea, and air
  traffic were hampered.

                 Super Typhoon Wutip  (TC-16W / TY 0112)
                          26 August - 4 September

  Wutip: contributed by Macau, is the Macanese word for butterfly

  A. Origins

     An area of convection developed over the Philippine Sea west of Guam
  on 25 August; a STWO issued by JTWC at 0600 UTC noted that a weak LLCC
  with associated scattered deep convection lay within a broad monsoon
  circulation.  A 200-mb analysis indicated weak to moderate vertical
  shear over the region.   The system began to develop fairly quickly;
  the development potential was upgraded to fair at 26/0100 UTC, and a
  TCFA was issued at 0400 UTC, upgrading the potential for development to
  good.    The disturbance was centered approximately 340 nm north-
  northwest of Guam at the time.  Another 200-mb analysis indicated good
  diffluence aloft with a possible anticyclone forming over the area.
  Deep convection was scattered but improving in organization; moderate
  vertical shear was still inhibiting development somewhat.

     JTWC issued the first warning on TD-16W at 0000 UTC on the 27th,
  locating the center about 330 nm northwest of Guam.  The initial MSW
  of 30 kts was based on CI estimates of 25, 30 and 35 kts.  Organization
  had improved markedly over the past six hours with an increase in deep
  convection noted.  (NOTE: The JMV file from JTWC classifies the system
  as a 25-kt tropical depression at 26/1800 UTC--six hours prior to the
  issuance of the first warning.)

     JTWC upgraded the depression to a tropical storm at 27/0600 UTC with
  the center located approximately 325 nm northwest of Saipan.  The MSW
  was estimated at 35 kts--this was upped to 45 kts six hours later.
  Also at 1200 UTC, JMA upgraded the system to Tropical Storm Wutip with
  40-kt winds (10-min avg), and NMCC also classified Wutip as a tropical
  storm at this time.

  B. Track and Intensity History

     Throughout its life Wutip tracked generally northeastward along a
  reverse-oriented monsoon trough under the influence of a mid-level
  ridge to its southeast.   Tropical Storm Wutip's intensification
  proceeded at a rapid pace.   An eye feature was seen developing at
  28/0000 UTC so JTWC upgraded Wutip to a typhoon only 18 hours after
  it had been declared a tropical storm.   The fledgling typhoon was
  located slightly more than 100 nm west of the northernmost Marianas
  Islands at the time.  By 0600 UTC a 12-nm irregular cloud-filled eye
  had become visible, and a 28/1055 UTC SSM/I pass depicted a primary
  banding feature wrapping in toward the vortex center from the north-
  west.   The MSW was upped to 90 kts at 1200 UTC and to 115 kts at
  1800 UTC when Wutip was centered about 250 nm southeast of the island
  of Iwo Jima.

     Continuing to the northeast, Wutip had reached a point about 250 nm
  east-southeast of Iwo Jima by 29/0600 UTC.  Based on CI estimates of
  127 and 140 kts, JTWC increased the MSW to 130 kts, making Wutip the
  first super typhoon of the year.  The warning noted that interaction
  with an upper-level trough to the northwest had resulted in rapid
  intensification of the system.    Gales covered an area 180 nm in
  diameter around a well-defined 10-nm round eye.  The diameter of the
  area of 50-kt winds was 100 nm while the maximum radius of 100-kt
  winds was estimated at 25 nm.  Wutip was maintained as a super typhoon
  for only six hours; at 1200 UTC all the CI numbers were 6.5 so the
  MSW was reduced to 125 kts.   Typhoon Wutip's center passed about
  300 nm due east of Iwo Jima at 29/1800 UTC.

     By 30/0000 UTC the storm displayed a 20-nm eye with warming cloud
  tops; however, one CI estimate of 140 kts was received so the MSW
  remained at 125 kts, but was lowered slightly to 120 kts six hours
  later.  As Typhoon Wutip continued to move northeastward away from the
  tropics and into the subtropical zone, it began to weaken.    At 1800
  UTC on 31 August animated infrared imagery depicted a reduction in the
  coverage of deep convection; the intensity had been reduced to 75 kts
  by that time.  The JTWC warning at 0000 UTC on 1 September noted that
  Wutip was beginning to enter the early stages of extratropical
  transition, although at 0600 UTC the storm still had a fairly well-
  defined banding eye feature with the MSW estimated to be 70 kts at
  the time.

     A SSM/I pass at 01/1004 UTC revealed that deep convection was
  confined to the eastern semicircle, and by 1800 UTC dry air entrainment
  into the western semicircle had led to further weakening.  JTWC down-
  graded Wutip to a 60-kt tropical storm at this time with further
  weakening forecast.  The center had become partially-exposed by
  02/0000 UTC, and Wutip had become more-or-less completely extratropical
  by 1800 UTC.  JTWC issued the final warning on the cyclone at 1800
  UTC, placing the center almost 900 nm east of Tokyo.  The remnants
  of Wutip continued moving northeastward as a slowly weakening extra-
  tropical gale.  By 0600 UTC on 4 September the system, still producing
  winds to 35 kts, had crossed the Dateline well to the south of the
  westernmost Aleutian Islands.

     To summarize, Super Typhoon Wutip's peak intensity of 130 kts (per
  JTWC's warnings) was reached on 29 August at 0600 UTC.  The MSW was
  estimated at 115 kts or greater from 28/1800 UTC through 30/1800 UTC.
  The minimum CP assigned by JMA was 930 mb from 29/1200 UTC through
  30/0600 UTC.

  C. Comparisons Between JTWC and Other Centers

     Center position coordinates were in very good agreement between the
  various warning centers throughout the life of Wutip.    Intensity
  estimates between JTWC and JMA agreed well during the earlier and
  latter stages of the storm's history.  JMA's peak estimated 10-min avg
  wind was 90 kts from 29/1200 through 30/0600 UTC.  This was slightly
  after the time of JTWC's peak of 130 kts (29/0600 UTC).   A little
  surprisingly, NMCC's maximum 10-min avg MSW estimate was also only
  90 kts--from 29/0600 through 30/1200 UTC.  

  D. Damage and Casualties

     Around the time that Wutip was reaching typhoon intensity, it passed
  close enough to the Northern Marianas such that the outer fringes of 
  the storm would have affected the islands.    However, I have not 
  received any reports of damage or casualties resulting from Wutip.  If
  any become available later they will be reported in a future summary.

                 Tropical Storm Sepat  (TC-17W / TS 0113)
                          27 August - 1 September

  Sepat: contributed by Malaysia, is the name of a freshwater fish
         often found in rivers and swampy areas with lots of weeds,
         and also in paddy fields

  A. Origins

     A very active and extensive monsoon trough covered most of the
  Western North Pacific in late August.  Tropical Depression 15W as
  well as named storms Wutip, Sepat, and Fitow all had their origins as
  circulations in the trough.  There were numerous circulations, ranging
  from small eddys with only one or two thunderstorms to the intense
  Super Typhoon Wutip.  Tracing the origin of Tropical Storm Sepat using
  the daily STWOs issued by JTWC led to a long journey around the NWP
  basin.  The discussion below is based on what I gleaned from the STWOs,
  using the "previously located near" coordinates to piece together the
  continuity from day to day.    However, it seems fantastic that one
  single, weak LLCC could make such a tour of the Western Pacific for
  over a week, at times making a quantum leap of several hundred miles
  from one day to the next.   Given the numerous circulations crawling
  around in the huge monsoon trough, which some meteorologists dubbed
  "a marvel of nature", it seems likely that there were flare-ups of
  convection here and there which may or may not always have been
  directly traceable to a flare-up seen the previous day.

     The STWO issued by JTWC at 0600 UTC on 19 August mentioned that an
  area of convection was developing very deep in the tropics roughly
  100 nm south of Pohnpei.  Bands of deep convection were forming south
  of a broad LLCC.  A 200-mb analysis indicated 20 kts of easterly shear
  over the area.   The STWO for 20/0600 UTC indicated that the area of
  convection was southwest of Chuuk--over 500 nm west of the previous
  day's position.  The existence of a broad LLCC was supported by
  animated visible imagery and synoptic reports.   At 0600 UTC on the
  21st the area of convection was relocated about 350 nm to the west-
  northwest to a position south-southwest of Guam.  Moderate to strong
  vertical shear overlay the disturbance.

     By 22/0600 UTC the disturbance had migrated east-northeastward to a
  point south-southeast of Guam.    A 22/0000 UTC surface analysis had
  indicated a broad LLCC; however, a QuikScat pass had been unable to
  resolve a single circulation but rather had revealed multiple areas
  of turning within the monsoon trough.   An interim STWO issued at
  2000 UTC relocated the disturbance to a position farther north over
  the Northern Marianas.  Synoptic data indicated that a weak LLCC had
  formed in the monsoon trough and appeared to be merging with a shear
  line extending northeastward from the islands.  Several bursts of
  convection had been noted along the trough.

     At 0600 UTC on the 23rd the area of convection was relocated to a
  point a couple hundred miles east of the Marianas.  The majority of
  the deep convection remained south of the LLCC in low-level convergent
  flow.  The system remained quasi-stationary on the 24th, but by 0600
  UTC on 25 August had again been repositioned a couple hundred miles
  to the east with little change in structure.   At 0600 UTC on the 26th
  the disturbance was relocated about 400 nm to the east of the previous
  day's position.  The LLCC was by then located about 1000 nm east of
  the Marianas and had moved into a region of favorable vertical shear.
  JTWC upgraded the development potential to fair.   A TCFA was issued
  at 26/1700 UTC with the LLCC estimated to be about 225 nm west of
  Wake Island.  Animated satellite imagery indicated a convective band
  forming southwest of the LLCC with improving overall organization
  noted.  Vertical shear was weak and the system had good outflow aloft.

     JTWC issued the first warning on TD-17W at 27/0000 UTC with the
  center located about 250 nm northwest of Wake Island and moving north-
  northwestward at 14 kts.  The initial MSW of 30 kts was based on CI
  estimates of 25 and 30 kts.    JTWC upgraded the depression to a
  tropical storm at 1800 UTC when it was centered approximately 400 nm
  northwest of Wake Island and moving northward at 8 kts.  Six hours
  later JMA upgraded the cyclone to Tropical Storm Sepat.  JTWC upped
  the MSW to 45 kts (which turned out to be the peak intensity) at the
  same time based on CI estimates of 45 and 55 kts.  Also, a recent
  QuikScat pass had shown uncontaminated winds of 40 kts.  A 200-mb
  analysis indicated that Sepat was experiencing enhanced outflow due
  to a TUTT lying to the northwest.   NMCC was the last warning agency
  to upgrade Sepat to tropical storm status--they did so at 0600 UTC
  on 28 August.

  B. Track and Intensity History

     Tropical Storm Sepat tracked on a course just west of due north for
  its entire life span as a tropical cyclone.  The storm was steered on
  its poleward course by a strong mid-level HIGH centered generally east-
  northeast of the cyclone.  As noted above the maximum MSW assigned by
  JTWC was 45 kts, and the peak 10-min avg MSW estimated by JMA was
  40 kts.  At 28/0600 UTC satellite imagery revealed new deep convection
  building over the vortex center, but a 28/0915 UTC SSM/I pass depicted
  a significant decrease in overall coverage of convection, although low-
  level cloud lines were still well-defined.   By 29/0000 UTC Sepat had
  moved to a position about 1000 nm west of Midway Island.  A SSM/I pass
  at 28/2009 UTC revealed only scattered deep convection associated with
  the circulation.  JTWC decreased the intensity to 35 kts at this time.

     By 1800 UTC Sepat was located approximately 1250 nm west-northwest
  of Midway and moving north-northwestward at 29 kts.  The concurrent
  JTWC warning indicated that the storm was becoming extratropical.
  JTWC issued their final warning at 0000 UTC on the 30th with Sepat
  located about 870 nm east-southeast of Misawa, Japan.  The initial
  warning estimated the MSW at 25 kts, but later receipt of QuikScat
  data indicating winds to 30 kts, and a ship report of 30 kts, led to
  the issuance of an amended warning raising the winds to 30 kts.
  However, Sepat was forecast to be completely extratropical in 12 hours,
  so JTWC did not issue any further warnings.  JMA, however, maintained
  Sepat as a 40-kt tropical storm for another 30 hours as the system
  turned to the east-northeast and accelerated.  JMA deemed Sepat to be
  extratropical at 31/1200 UTC, and the final reference to this system
  in JMA's High Seas Bulletins placed it near the Dateline south of the
  Aleutians at 0000 UTC on 1 September as a weakening gale.

  C. Comparisons Between JTWC and Other Centers

     Center position coordinates were in good agreement between JTWC,
  JMA and NMCC for Tropical Storm Sepat.  And, as noted above, intensity
  estimates between JTWC and JMA were also in excellent agreement,
  although JMA carried the storm as a tropical entity for over a day
  longer than JTWC.   NMCC's intensity estimates were the lower of the
  three TCWCs--Sepat was maintained as a minimal 35-kt tropical storm
  for the entire period in which NMCC issued warnings.

  D. Damage and Casualties

     Tropical Storm Sepat did not affect any populated areas, and no
  damage or casualties are known to have resulted from this tropical

                  Tropical Storm Fitow  (TC-18W / TS 0114)
                                28 - 31 August

  Fitow: contributed by the Federated States of Micronesia, is the
         Yapese name for a beautiful fragrant flower

  A. Origins

     The STWO issued by JTWC at 0600 UTC on 26 August noted that an area
  of convection had developed west of Luzon in the South China Sea. 
  Synoptic data and satellite imagery indicated a broad LLCC within the
  monsoon trough.   CIMSS shear products indicated moderate vertical 
  shear over the region.  Disturbed weather had persisted in the northern
  South China Sea for a good portion of the month of August.  As noted
  in the introductory section on NWP activity for August, there was
  possibly a connection between the circulation(s) classified by PAGASA
  as Tropical Depression Jolina and the later Tropical Storm Fitow.

     By 0600 UTC on the 27th the system had drifted slightly to the west
  of the previous day's position.     JTWC upgraded the development 
  potential to fair since convection was increasing in organization near
  the LLCC.   By 28/0600 UTC the LLCC was again farther to the west at
  a position about 300 nm south-southwest of Hong Kong.  Animated visible
  imagery depicted a broad LLCC with associated cloudiness along the
  periphery of the system.     Synoptic data also indicated monsoon
  depression characteristics.  A 200-mb analysis revealed improving
  environmental conditions conducive to development.  HKO was the first
  warning agency to issue warnings--at 28/1200 UTC they issued the first
  warning on a 25-kt depression located about 285 nm south-southwest of
  Hong Kong.    JTWC issued a TCFA for the system at 0900 UTC on the

     JTWC issued the first warning on TD-18W at 29/0000 UTC, locating the
  center approximately 210 nm southwest of Hong Kong, moving west-
  northwestward at 7 kts.  JMA and NMCC also classified the system as a
  tropical depression at 0000 UTC.  By 1200 UTC the center of TD-18W was
  located over the northeastern coast of Hainan Dao.  JTWC assessed the
  MSW to be 25 kts based on satellite intensity estimates and synoptic
  ship reports of 25 kts.   The depression subsequently moved slowly
  westward across the northern portion of the island.

     By 0600 UTC on 30 August the depression's center was near the north-
  west coast of Hainan Dao, moving out into the Gulf of Tonkin.  NMCC
  upgraded the system to a 35-kt tropical storm at this time with JTWC
  and HKO both upgrading the depression to a tropical storm at 1200 UTC.
  The center was by this time over the Gulf of Tonkin moving slowly 
  northwestward.  Convection associated with the LLCC had increased and
  there was good outflow to the south.   Also, SSM/I and TRMM imagery 
  revealed a more organized LLCC embedded in the convection.

  B. Track and Intensity History

     By 1800 UTC Tropical Storm 18W had turned to a slow northward track 
  toward the coast of China.  JTWC estimated the MSW at 35 kts based on
  CI estimates of 35 and 45 kts.   At 31/0000 UTC both JTWC and NMCC
  increased the intensity to 40 kts; also at 0000 UTC, JMA upgraded the
  system to a tropical storm, naming it Fitow.  By 0600 UTC on the 31st,
  Tropical Storm Fitow's center was on the coast of China near Dongxing,
  moving north-northwestward at 6 kts.   JTWC maintained 40 kts as the
  MSW based on satellite intensity estimates of 35 and 45 kts and a
  synoptic report of 40 kts from near the center.  JMA, however, down-
  graded Fitow to a 30-kt depression at 0600 UTC.  By 1200 UTC Fitow was
  inland and dissipating over southwestern China and all the other TCWCs
  downgraded the system to depression status.  This was JTWC's final
  warning, but NMCC and HKO each issued one more bulletin on Fitow at
  1800 UTC.

  C. Meteorological Aspects

     Huang Chunliang has sent me several meteorological observations
  from southern China.  The depression's center first made landfall
  near Wenchang City in Hainan Province around 1130 UTC on 29 August.
  According to some information Chunliang received from NMCC, Fitow
  dropped in excess of 700 mm of rain at some location (site unknown)
  on the island of Hainan--a very rare occurrence.

     The storm's final landfall occurred just southwest of Beihai City
  (21.5N, 109.1E) around 31/0300 UTC.  At 31/0000 UTC Beihai recorded
  a SLP of 988 mb with sustained winds (presumably a 10-min avg) of
  23 kts, gusting to 37 kts.  At 0600 UTC the station reported a SLP
  of 996 mb with mean winds of 17 kts, gusting to 47 kts.

     Dongfang City recorded 815.3 mm of rainfall during the 8-day
  period from 27/1700 UTC through 2000 UTC on 4 September.  A location
  within Changjiang County recorded 831.1 mm during the 72-hour period
  ending at 0800 UTC on 31 August with 404 mm falling during a 12-hour
  period on the 30th.  Several locations recorded rainfall amounts in
  excess of 400 mm in the 72 hours ending at 31/0800 UTC.   Wenchang
  City on Hainan Dao recorded 245 mm in the 30 hours ending at 1400
  UTC on 29 August.

     Several stations in the Hong Kong area reported winds gusting in
  excess of gale force on 28 and 29 August when the depression was
  nearest to Hong Kong.  Some of these observations were: 44 kts at
  Cheung Chau, 41 kts at North Point, 52 kts at Tai Mo Shun, and 54 kts
  at Waglan Island.   Sustained winds in general were well below gale
  force except at Tai Mo Shun where mean winds reached 34 kts.  Several
  stations in the Hong Kong area neared or exceeded 200 mm of rainfall
  for storm totals with the highest being 255 mm at Sha Tin and 227 mm
  at Jordan Valley.   More detailed information can be found in a storm
  report on Fitow located on HKO's website (see Section E below for
  the URL).

  D. Comparisons Between JTWC and Other Centers

     Center position coordinates were in fairly good agreement between
  the several warning centers for Fitow, especially considering that it
  was a weak, disorganized system.  Although JMA classified the cyclone
  as a tropical storm for only one warning cycle, the difference between
  it and the other TCWCs was only a matter of 5 kts--it just happened to
  involve that very arbitrary but very important threshold of 34 kts.
  NMCC was the first agency to upgrade the system to tropical storm
  status (at 30/0600 UTC), and JTWC and HKO did so six hours later.
  Twelve hours elapsed before JMA issued their only tropical storm
  warning on the system, officially naming it Fitow.    The maximum
  intensity estimated for Fitow was 40 kts, from both JTWC (1-min avg)
  and NMCC (10-min avg); the peak 10-min mean winds reported by JMA and
  HKO remained at 35 kts.

  E. Damage and Casualties

     As of 31 August, total economic losses in Hainan were estimated at
  1.367 billian yuan.  Over two million residents of the province were
  seriously affected by the storm, 1300 houses were destroyed, 106.5
  thousand hectares of farmland were badly stricken, and 26,700 head of
  livestock were reported dead.  In Guangdong Province almost a million
  and a half residents were seriously affected with 2380 houses toppled.
  There were also four deaths reported in the province.   In the Hong
  Kong area two persons drowned when they were swept away by waves.

     The Hong Kong Observatory has prepared a report on Tropical Storm
  Fitow which can be found at the following website:>

     (A special thanks to Chunliang for sending me all the information
  on the effects of this tropical storm.)


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

  Activity for August:  No tropical cyclones


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

  Activity for August:  No tropical cyclones



  Activity for August:  No tropical cyclones


  Activity for August:  No tropical cyclones


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

  Activity for August:  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
           August as an example:   aug01.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:  aug01.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>>>>

  NOTE:  The URL for Michael V. Padua's Typhoon 2000 website has
  changed slightly once more.

     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:>


     JTWC now has available on its website the complete Annual Tropical 
  Cyclone Report (ATCR) for 2000 and a report on the 2000-2001 season in
  the Southern Hemisphere.  ATCRs for earlier years are available also.

     The URL is:>

     Also, TPC/NHC has available on its webpage nice "technicolor"
  tracking charts for the 2000 Atlantic and Eastern North Pacific
  tropical cyclones; also, preliminary storm reports for all the 2000
  Atlantic and Eastern North Pacific cyclones are now available, as
  well as track charts and reports on storms from earlier years.

     The URL is:>

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


Document: summ0108.htm
Updated: 27th December 2006

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