Tropical Cyclones
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Monthly Global Tropical Cyclone Summary July 1999
[Summaries and Track Data] [Prepared by Gary Padgett]


                               JULY, 1999

  (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.)


                             JULY HIGHLIGHTS

  --> North Pacific activity increases but average intensity quite weak

                           ACTIVITY BY BASINS

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

  Activity for July:  1 tropical depression

  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.   Also, some information on Tropical Depression #2
  was obtained from the preliminary report on this system already
  available on TPC/NHC's website.

                        Atlantic Activity for July

     No named tropical storms or hurricanes were noted in the Atlantic
  basin during July, but there were a couple of significant tropical
  weather systems.   The first was Tropical Depression #2 which formed
  from a tropical wave that had left the coast of Africa on 20 Jun. The
  wave reached the extreme western Caribbean Sea on 30 Jun and a broad
  area of mid-tropospheric turning was noted.   The wave moved onto the
  Yucatan Peninsula on 1 Jul and a weak LOW moved out into the Bay of
  Campeche early on the 2nd.   During the day deep convection became
  better organized and a tropical depression had formed by 1800 UTC
  about 200 nm southeast of Tampico, Mexico.   The depression continued
  moving west-northwestward and the center had crossed the coast about
  35 nm south-southeast of Tuxpan by 0400 UTC on 3 Jul.     Reported
  rainfall totals ranged from 105 to 317 mm.    There were no known
  casualties or significant damage.

     The second significant tropical weather system of July was a
  tropical wave which left the coast of Africa on the 3rd and moved
  rapidly westward across the Atlantic.     The wave had reached the
  eastern Caribbean Sea on 8 Jul when it was investigated by U. S. Air
  Force Reserves Hurricane Hunters.   The reconnaissance flight found
  flight-level and surface winds in excess of 45 kts in squalls, mainly
  west of the wave axis.   This unusual wave was propagating westward
  at 20-25 kts--faster than the environmental easterly flow.   As the
  wave approached Honduras early on 10 Jul it was becoming better
  organized.  A reconnaissance flight found a weak low-pressure area
  just inland over northeastern Honduras with strong, gusty winds to
  the north and northeast of the LOW.   Deep convection with cloud
  tops colder than -80 C had developed in bands within 120-240 nm of
  the center with weak to moderate convection near the surface center.
  Upper-level cirrus outflow had also become better defined.   The
  surface LOW skimmed along the northern Honduran coast and inland
  over southern Belize and Guatemala.   The system almost became a
  tropical depression and would likely have done so were it not for
  the fact that the area of minimum pressure remained inland or right
  along the coast.    This tropical wave subsequently crossed Central
  America and moved out into the Eastern Pacific where it developed
  into a tropical depression (TD-03E).

     This tropical wave was likely prevented from developing into a
  tropical cyclone due to its very rapid translational speed.  No doubt,
  relative to the wave axis, a circulation existed, but in order to
  qualify as a tropical cyclone a complete circulation must exist for
  a stationary point on the earth's surface--evidenced by a westerly
  wind on the equatorward side of the disturbance.      Such strong
  gale-bearing tropical waves are not common, but they do occur
  occasionally in the Atlantic.   A strong wave passed through the
  central Caribbean in September, 1992.  Easterly winds to around 50 kts
  were reported by ships and a reconnaissance flight on the northern
  side of the disturbance when it was south of Hispaniola, but on the
  south side of the wave only easterly winds were reported.   The
  tropical waves which produced Hurricanes Camille of 1969 and Erin of
  1995 both contained sustained winds well above tropical storm force
  before a surface circulation had become established.   In each case,
  when the surface circulation did develop, the system was upgraded
  immediately to a tropical storm.

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

  Activity for July:  3 tropical depressions
                      1 tropical storm
                      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.   Some information was
  obtained from preliminary storm reports located on TPC/NHC's website.

                  Northeast Pacific Activity for July

     One rather strong hurricane (Category 3 on the Saffir/Simpson
  Scale) plus four weak, short-lived systems roamed tropical Northeast
  Pacific waters during July.   Beatriz became the region's second
  hurricane of 1999 and the first to become a major hurricane, but
  the storm remained far from any populated areas.   The other four
  systems were quite weak and short-lived with Calvin being the other
  named storm during the month, and a minimal tropical storm at that.

     Due I suppose to the relative inactivity in the Atlantic and North-
  east Pacific basins during July and early August, the staff of TPC/NHC
  found time to prepare some preliminary reports for all the Northeast
  Pacific systems in July except for Hurricane Beatriz.  I have used the
  analyzed Best Tracks from the preliminary storm reports on the other
  systems in the companion cyclone tracks file document.   Tropical
  Depression 03E developed from the very active tropical wave which
  crossed the Atlantic, Caribbean, and Central America during early and
  mid-July.  (See the section of this summary covering the Atlantic
  basin for a description of the early history of this system.)  The
  tropical wave emerged into the Eastern Pacific on 13 Jul and was
  upgraded to a depression at 0600 UTC on the 14th when it was centered
  about 225 nm southwest of Manzanillo.  The system at one point had
  a very large, impressive area of deep convection, but after the
  depression had formed it remained very ill-defined.  TD-03E moved
  generally westward and dissipated around 15/1800 UTC about 450 nm
  southwest of Cabo San Lucas.   After 1200 UTC on 14 July, the official
  Best Track positions differ by almost 100 nm from the operational
  warning positions, and the final advisory position at 15/1200 UTC
  is almost 200 nm south of the Best Track location for that time.

     Tropical Depression 04E formed on 23 July from a tropical wave which
  had entered the Pacific on 15 July.      At 0000 UTC on the 23rd the
  center was about 1300 nm west-southwest of Cabo San Lucas.      The
  depression moved generally westward and into the Central North Pacific
  region on 24 Jul, dissipating about 725 nm east-southeast of Hilo,
  Hawaii, by 25/0000 UTC.

     A tropical wave which left the African coast on 5 July, immediately
  behind the active wave which ultimately spawned TD-03E, crossed the
  Atlantic and Caribbean and eventually reached the Eastern Pacific where
  by 26 July it began to show increased convective organization.  The
  first advisory on TD-06E placed the center about 1100 nm southwest of
  Cabo San Lucas at 1800 UTC on 26 Jul.  The depression moved northwest-
  ward and encountered vertical shear which did not allow the system to
  intensify into a tropical storm.  The depression had dissipated by
  28/0000 UTC.

                       Hurricane Beatriz  (TC-02E)
                               9 - 16 July

     Hurricane Beatriz developed from an area of disturbed weather near
  the Gulf of Tehuantepec which was first mentioned by TPC/NHC on 6 Jul.
  The disturbed area drifted westward, slowly becoming better organized,
  and was upgraded to a tropical depression at 0600 UTC on 9 Jul when it
  was centered approximately 275 nm southwest of Acapulco, Mexico.  The
  depression exhibited good outflow in all quadrants, and with Dvorak
  intensity estimates of T2.5 and T3.0 from TAFB and SAB, respectively,
  was upgraded to Tropical Storm Beatriz only six hours later.  Tropical
  Storm Beatriz (Spanish form of Beatrice--pronounced "bay-ah-TREECE")
  continued moving westward and slowly intensified.   A U. S. Navy
  FNMOC scatterometer pass indicated a wind of 41 kts about 150 nm
  northeast of the center around 1800 UTC on 10 Jul.

     Beatriz was upgraded to a hurricane at 1200 UTC on 11 Jul when the
  center was estimated to be about 575 nm south-southwest of Cabo San
  Lucas.   By 12/0000 UTC cloud tops of -65 to -70 C were wrapping
  three-quarters of the way around the eye, and the MSW was estimated
  at 85 kts.  The hurricane exhibited good banding features and outflow
  was well-developed in all quadrants except the northwest.   Beatriz
  apparently underwent a concentric eyewall cycle during the 12th.  By
  1800 UTC the storm displayed a well-defined eye 21 nm in diameter and
  T-numbers from TAFB and SAB were up to T5.5, so the MSW was increased
  to 100 kts, making Beatriz the first major hurricane (Category 3 on
  the Saffir/Simpson scale) in the Eastern Pacific this season.  Six
  hours later the eye had become even tighter and the intensity was
  set at 105 kts--the maximum reached by Beatriz--with an attendant
  estimated central pressure of 956 mb.   Objective T-numbers were
  ranging around 5.6-5.7 during this time.  At peak intensity Hurricane
  Beatriz was located about 775 nm southwest of Cabo San Lucas on the
  southern tip of the Baja California Peninsula.

     Hurricane Beatriz to this point had been moving on a course just
  north of due west, but now the storm began to turn to more of a west-
  northwesterly course.   By 0600 UTC on 14 Jul Beatriz was nearing the
  25 C SST isotherm, the eye was becoming ragged and convective tops
  were warming, so the MSW was decreased to 95 kts.  Twenty-four hours
  later an eye was still visible, but the storm was beginning to weaken
  rapidly.   Beatriz was downgraded to a tropical storm at 16/0000 UTC
  as satellite imagery showed the low-level circulation to be de-coupling
  from the mid- and upper-level convective circulation.     Six hours
  later there were no convective tops colder than -50 C and a
  scatterometer pass found no winds higher than 30 kts except for perhaps
  near the center where there was no data available.      Since Dvorak
  estimates were slightly higher, the MSW was set at 40 kts for the
  0900 UTC advisory, but the storm was downgraded to a dissipating
  depression six hours later since all that remained was a tight swirl
  of low clouds.  Dvorak numbers still supported minimal tropical storm
  intensity, but, as Lixion Avila pointed out in a Discussion Bulletin,
  the Dvorak estimates were constrained by rules which were not designed
  for weakening swirls over cool Eastern Pacific waters.     The final
  advisory placed the dissipating system about 1300 nm west-southwest
  of Cabo San Lucas at 16/1800 UTC.

                     Tropical Storm Calvin  (TC-05E)
                              25 - 27 July

     Tropical Storm Calvin was a "one-day wonder" which barely qualified
  as a tropical storm.  The parent tropical wave left the African coast
  on 9 Jul and entered the Eastern Pacific on the 20th.   A mid-level
  circulation was evident on the 23rd, and an elongated low-level center
  formed within the ITCZ on 24 Jul but did not exhibit enough organized
  convection to warrant depression classification.   The first visible
  satellite images on 25 Jul revealed a low-level circulation center
  located on the northwest edge of a cluster of deep convection, so
  the disturbance was classified as a tropical depression.  The first
  warning position, at 25/0600 UTC, placed the depression's center
  about 575 nm south-southwest of Cabo San Lucas.   During this period
  the Pacific Ocean north of 16N and between 115W and 140W was dominated
  by a large, upper-level trough which was responsible for fairly
  strong northwesterly shearing over the region.

     Dvorak estimates from TAFB and SAB had reached 35 kts by 0600 on
  26 Jul, so the depression was upgraded to Tropical Storm Calvin.
  However, the shearing persisted and Calvin soon began to weaken and
  was downgraded back to a depression only 12 hours later when satellite
  intensity estimates were 35 kts, 30 kts, and 25 kts, respectively, from
  TAFB, SAB, and AFGWC.   This system moved on a west-northwesterly track
  through most of its existence, turning more to the northwest on 27 Jul.
  The 27/0300 UTC advisory noted that there had been a recent burst of
  convection near the center with the suggestion of a convective band
  extending from the east to the south of the center, but this feature
  did not persist for long.  By 1500 UTC the weak low-level center
  appeared to be weakening into an open wave.  The final Best Track
  position on Calvin, at 1200 UTC, places the dissipating center about
  800 nm west-southwest of Cabo San Lucas.

     One interesting aspect of Tropical Storm Calvin is that
  operationally, Calvin was carried as a tropical storm only from 0600
  UTC to 1800 UTC on 26 Jul, but according to the official Best Track,
  the tropical storm portion of the system runs from 25/1200 UTC through
  26/0600 UTC.   However, the Best Track's MSW never rises higher than
  35 kts, which was the highest operationally assigned value.


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

  Activity for July:  1 tropical depression
                      3 tropical storms **
                      1 typhoon

  ** - two of these were classified as tropical storms only by JMA;
       JTWC carried them only as tropical depressions.

  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.  Also, as
  announced earlier in a separate posting, a column of 10-min avg MSW
  is included--the values being obtained from either PAGASA's or JMA's
  advisories.  A special thanks to Michael V. Padua, owner of the
  Typhoon '99 webpage, for sending me the PAGASA and JMA tracks.

     In the title line for each storm I plan to reference all the cyclone
  names/numbers I have available:  JTWC's depression number and 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 Activity for July

     It was a month of interesting discrepancies between the various
  warning centers in matters of tropical cyclone classification.  JTWC,
  which normally has the more liberal warning criteria, named only two
  tropical storms while JMA classified two other systems as tropical
  storms that were treated as only tropical depressions by JTWC.    And
  during the early stages of Tropical Storm Neil, PAGASA had upgraded the
  disturbance to Tropical Storm Helming before JTWC had even initiated
  tropical depression warnings!    One system was carried as a tropical
  depression by JTWC that was not warned on by any other agency (at least
  to the author's knowledge).   This system, TD-08W, formed on 21 Jul
  about 200 nm north-northeast of Okinawa and moved generally northward
  and into the southwestern tip of the Korean peninsula.  A track is
  given for this depression in the Global Tropical Cyclone Tracks file
  for July.   Since two of the tropical depressions were treated as
  tropical storms by JMA, I will give them individual coverage below.

                    Tropical Storm  (TC-07W / TS 9904)
                               15 - 18 July

     The first unnamed tropical storm of July (as per JMA) can be traced
  to an area of disturbed weather which was located about 600 nm east-
  northeast of the Northern Marianas Islands on 13 Jul.  By the 14th a
  very weak low-level circulation center was exposed to the northeast of
  a area of convection.  The convection was drifting to the southwest
  and had good outflow aloft, and the Tropical Weather Outlook from JTWC
  indicated the possibility of a new center forming under this
  convection.  JTWC issued the first tropical depression warning at
  0000 UTC on 15 Jul, placing the low-level center about 500 nm east-
  northeast of the northern tip of the Marianas.  The warning indicated
  that intensification of the depression was being hindered by some
  shearing as a result of its being caught between two subtropical
  ridges, one to the east and one to the west.   The next warning 
  relocated the depression's center to the north-northwest somewhat.

     Beginning around 1800 UTC on 15 July, TD-07W began moving on more of
  a west-northwesterly course which it maintained throughout most of its
  life.   The depression was steered primarily by a subtropical ridge
  to its east-northeast, and remained in a moderate shearing environment
  created by an upper-level LOW to its northeast.   JMA upgraded the
  depression to a tropical storm with 35-kt MSW (10-min avg) at 1800 UTC
  on 16 Jul and maintained it as a tropical storm for 30 hours.  JTWC
  initially forecast the system to reach tropical storm status, but
  by 17/0000 UTC the forecast no longer called for this since the low-
  level center had become completely exposed 80 nm north-northwest of
  the strongest convection.

     Late on the 17th the system began moving on more of a northerly
  track in response to a passing trough to the north.   Vertical shear
  increased and the depression began to rapidly dissipate.  The final
  JTWC warning at 18/0600 UTC placed the dissipating center about 400 nm
  south-southeast of Tokyo.

     Discrepancies in warning positions between JMA and JTWC were greater
  than normal, and may give a clue as to why JMA happened to classify 
  this disturbance as a tropical storm.  Most of the time, especially 
  during the tropical storm stage, JMA's position was generally about
  70-80 nm southeast or south-southeast of JTWC's position.  Since this
  system experienced mainly northwesterly shear, the main convective
  mass was usually southeast of JTWC's placement of the low-level center
  of circulation.   If JMA's analysts were consistently assessing the
  low-level center to be nearer or under the deeper convection, then
  it is not surprising that they considered the system to be stronger
  than did JTWC.

             Tropical Storm Neil/Helming  (TC-09W / STS 9905)
                               21 - 28 July

     A Significant Tropical Weather Outlook (STWO) from JTWC on 19 Jul
  mentioned a symmetrical area of convection located east of Luzon
  but there was no low-level circulation apparent.  PAGASA initiated
  depression advisories on this disturbance at 0000 UTC on 21 Jul
  when it was located roughly 300 nm east-southeast of Cabo Engano
  (the northeastern tip of Luzon), naming the depression Helming.  The
  system moved very little over the next couple of days, drifting very
  slowly northwestward.   PAGASA upgraded Helming to a tropical storm
  the next day when the center was estimated to be about 250 nm east-
  southeast of Cabo Engano.   By the 23rd PAGASA was reporting the
  MSW (10-min avg) to be 45 kts; yet the SWTO from JTWC on that day
  indicated a completely exposed low-level center about 100 nm north of
  the nearest deep convection with maximum winds in the area estimated
  at only 15-20 kts.   This obviously represents a major disagreement
  between warning centers in interpretation of satellite imagery.

     PAGASA had dropped the winds back to 35 kts on 24 Jul, but the SWTO
  from JTWC indicated that convection had increased in areal coverage and
  a 24/0000 UTC surface analysis indicated a low-level circulation center
  might be present underneath the convection.   A Formation Alert was
  issued at 24/2130 UTC and JTWC initiated depression warnings at 0600
  UTC on 25 Jul when the center was estimated to be located about 200 nm
  south-southwest of Okinawa.  At the same time PAGASA increased the
  10-min MSW to 40 kts.   The tropical cyclone at this time was located
  in a very active monsoon trough which extended from the South China
  Sea, across Luzon, and northeastward to a point southeast of Okinawa.
  The system to be known as TD-10W / TS 9906 was taking shape at this
  time within the trough in the South China Sea.

     The cyclone continued generally northward, steered by a subtropical
  ridge to its east.  The center passed only about 20 nm east of Okinawa
  around 25/1800 UTC per JTWC's track (about 70 nm east per JMA's track).
  Kadena AB reported a sustained wind to 16 kts with gusts to 23 kts and
  a pressure of 986.4 mb as the system passed by.   JTWC's MSW estimate
  was 30 kts at this time, while interestingly, JMA's 10-min avg MSW
  estimate was 50 kts--approximately equivalent to a 1-min avg MSW of
  60 kts.     The system was upgraded to Tropical Storm Neil at 26/0000
  UTC, but JTWC's assigned MSW never rose higher than 40 kts.   JTWC
  upgraded the system to a tropical storm based upon animated satellite
  imagery which indicated convection to the north of the center had
  consolidated and was wrapping around the center.  Satellite current
  intensity estimates (received by JTWC) were around 30 kts, but
  apparently some synoptic reports indicated higher winds.

     After passing Okinawa Tropical Storm Neil turned to a course just
  west of due north in the direction of South Korea.   The convection
  began to weaken as the storm moved over cooler SSTs.  Neil passed just
  east of Cheju Island and moved over the extreme southwestern tip of
  South Korea around 0600 UTC on 27 Jul.  The weakening system skimmed
  up the western coast of South Korea and made a final landfall about
  20 nm southwest of Seoul around 28/0600 UTC.  There was no significant
  convection associated with the system at this time, and scatterometer
  data and synoptic reports indicated winds no higher than 15 kts.

                     Tropical Storm  (TC-10W / TS 9906)
                                26 - 27 July

     The second unnamed tropical storm of July (as per JMA) was a short-
  lived system which formed in the northern South China Sea and quickly
  made landfall in southeastern China just east of Hong Kong.  The daily
  STWO issued by JTWC first mentioned an area of convection on 21 Jul, 
  located in the northern South China Sea west of Luzon.   A mid-level 
  circulation was detected but was not reflected at the surface.  By the
  23rd a small, low-level center was noted embedded in the monsoon 
  trough.    The next day some anticyclonic flow was developing over 
  the region and convective organization was becoming slightly better.   
  Synoptic data at 25/0000 UTC indicated possible multiple circulation 
  centers in the South China Sea.
     JTWC issued the first tropical depression warning at 1800 UTC on
  26 Jul, placing the center about 120 nm south-southwest of Hong Kong
  and with MSW set at 25 kts.   Six hours later the system had moved
  northeastward and was located about 65 nm south-southeast of Hong
  Kong.  JTWC still estimated the MSW to be 25 kts, but JMA upgraded
  the system to a tropical storm with 40-kt MSW (10-min avg).   By
  0600 UTC on the 27th the center of the tropical storm was almost
  on the coast of China about 60 nm east-northeast of Hong Kong.  JMA's
  position at this time was slightly farther north and east.  This
  was the last bulletin from JTWC, but JMA issued advisories through
  1800 UTC, keeping the storm at 35 kts as it trekked north-northeastward
  through southeastern China.  It is not known to the author whether or
  not JMA's MSW estimates were based upon synoptic reports.

                   Typhoon Olga/Ising  (TC-11W / TY 9907)
                            28 July - 3 August

     A STWO issued by JTWC at 0600 UTC on 25 Jul mentioned that an area
  of convection south of Guam was becoming better organized, and the
  25/0000 UTC surface analysis indicated that a low-level circulation
  center might be forming.   The SWTO for the next day, however, placed
  the primary area of convection almost 600 nm to the west, and there
  was no further indication of a circulation forming.   JTWC issued a
  Formation Alert at 0230 UTC on 28 Jul, and this appears to be related
  to the previously mentioned disturbance.   High-resolution visible
  satellite imagery depicted a low-level center, and PAGASA initiated
  tropical depression advisories at 0600 UTC, naming the depression
  Ising.   Ising's center was east of the southern Philippines, about
  430 nm east of Surigao, a city on the northern tip of Mindanao.

     Tropical Depression Ising began moving on a north-northwestward
  course which it followed for a couple of days, steered by a
  subtropical ridge to the northeast.   Organization increased and JTWC
  initiated warnings at 29/0000 UTC.   By 1800 UTC deep convection east
  of the Philippines was forming into a spiral band feeding into the
  depression.   JTWC upgraded the system to Tropical Storm Olga at this
  time based on satellite intensity estimates of 30 kts and extrapolation
  of ship reports.   PAGASA also upgraded Ising to a tropical storm at
  1800 UTC.  Olga/Ising's center was located at this time about 550 nm
  east-northeast of Catanduanes Island in the Philippines.

     Olga/Ising continued moving north-northwestward until it crossed 
  20N around 1200 UTC on the 30th; then the storm turned to more of a
  northwesterly track.      The storm continued to slowly intensify,
  with PAGASA upgrading it to a typhoon at 31/0600 UTC when the center
  was estimated to be about 275 nm southeast of Okinawa.   JTWC followed
  suit six hours later.   Olga was initially forecast to become a rather
  intense typhoon, but its development was limited somewhat by dry air
  entrainment--the drier air likely resulting from subsidence associated
  with a TUTT.    By 0600 UTC on 1 Aug the dry air entrainment ceased
  and Olga displayed a small, completely-formed eye.  The typhoon had
  intensified slightly, reaching a peak MSW of 75 kts shortly before
  passing over the island of Okinawa.   Typhoon Olga passed directly
  over Okinawa around 1200 UTC, causing it to weaken slightly, but it
  soon regained its 75-kt winds after exiting the island.

     By 2 Aug Olga's motion turned to more of a northerly course as
  a mid-latitude trough to its west deepened.  The typhoon also began to
  accelerate.  Olga passed just west of Cheju Island around 03/0000 UTC
  as it slowly weakened, due primarily to cooler SSTs.  Olga passed near
  the southwestern tip of South Korea and then raced northward in the
  Yellow Sea, just brushing the western coast of South Korea.    At
  0600 UTC Kunsan AB reported gusts to 48 kts with a pressure of 984 mb.
  The storm was downgraded to a tropical storm at 1200 UTC with the low-
  level center displaced 112 nm from the nearest convection.   By 1800
  UTC, when JTWC and JMA each wrote the last advisory, Olga was inland
  over North Korea and rapidly losing tropical characteristics.

     Press reports located by the author indicate that 63 persons were
  killed or missing in South Korea from floods, landslides, and other
  rain-related accidents.    Olga's passage through the country came on
  the heels of several days of torrential rains, and widespread flooding
  was reported throughout much of the nation.    About 8500 homes were
  submerged in the floodwaters, and 25,000 persons were homeless.
  Agricultural losses were significant too--98,800 acres of rice paddies
  were reportedly washed away.        Heavy rains associated with the
  storm also fell on North Korea, leading to widespread flooding there.
  The author has not received any information about the effects of
  Typhoon Olga during its passage over Okinawa.   If anyone has any
  reports of the typhoon's passage over the island, please send them to
  me and I will include them in next month's summary.


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

  Activity for July: 1 tropical depression **

  ** - classified as a depression by IMD only

  NOTE:  The tracking and intensity information for North Indian Ocean
  Basin tropical cyclones is based primarily upon operational warnings
  from the Joint Typhoon Warning Center of the U. S. Air Force and Navy
  (JTWC) at Pearl Harbor, Hawaii.  Occasionally some information may
  be gleaned from the daily Tropical Weather Outlooks and other bulletins
  issued by the Indian Meteorological Department (IMD), which is the 
  WMO's RSMC for the basin.
     The MSW are based on a 1-min averaging period, which is used by
  all U. S. civilian and military weather services for tropical cyclone
  warnings.  For synoptic observations in the North Indian region,
  both 10-min and 3-min average winds are employed, but IMD makes no
  attempt to modify the Dvorak scale for estimating tropical cyclone
  intensity; hence, a 1-min avg MSW is implied.  In the North Indian
  basin JTWC usually does not initiate warnings until a system is
  well-organized and likely to attain tropical storm status within
  48 hours.

                   North Indian Ocean Activity for July

     The Indian Meteorological Department (IMD) classified one system
  as a depression during July.  A low-pressure area formed in the
  northern Bay of Bengal on 26 Jul, and by 0300 UTC on the 27th had
  organized into a tropical depression about 100 nm south-southeast of
  Calcutta.   The depression subsequently moved west-northwestward and
  inland into Orissa State near Dhiga early on 28 Jul.    The system
  became somewhat better organized and was classified as a deep
  depression by IMD (basically meaning 30-kt winds).  By 1200 UTC the
  system was inland and dissipating about 50 km northwest of Ranchi.
  This disturbance was mentioned by JTWC in their daily STWO's for the
  North Indian Ocean but was not classified as a tropical depression.


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

  Activity for July:  No tropical cyclones


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

  Activity for July:  No tropical cyclones


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

  Activity for July: 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 included in the July, 1998 summary.
  I will include this glossary from time to time, primarily in "lean"
  months without a lot of tropical cyclone activity to cover.  But if
  anyone missed receiving it and wishes to obtain a copy, send me an
  e-mail privately and I'll forward 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
           July as an example:   jul99.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:  jul99.sum, for

    Back issues can also be obtained from the following websites
  (courtesy of Michael Bath, Michael V. Padua, Tom Berg, and Michael

     Another website where much information about tropical cyclones may
  be found is the website for the UK Meteorological Office.  Their site
  contains a lot of statistical information about tropical cyclones
  globally on a monthly basis.  The URL is:>


     I have discovered that JTWC now has available on its new website
  the complete Annual Tropical Cyclone Report for 1997 (1996-1997 season
  for the Southern Hemisphere).   Also, tracks only for the 1998 tropical
  cyclones are currently available.

     The URL is:>

     Also, TPC/NHC has available on its webpage nice "technicolor"
  tracking charts for the 1998 Atlantic and Eastern North Pacific
  tropical cyclones; also, preliminary storm reports for all the 1998
  Atlantic and Eastern North Pacific cyclones are now available.

     The URL is:>

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


Document: summ9907.htm
Updated: 4th January 2007

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