MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
AUGUST, 2003
Part 2
(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: The August summary is being disseminated in two install-
ments. The first part covered tropical cyclones forming during the
first half of the month in all basins, plus contained the Feature of
the Month. This second installment covers storms forming during the
latter half of the month.
*************************************************************************
AUGUST HIGHLIGHTS
--> Bermuda struck by most intense hurricane in many decades (actually
in early September)
--> Strong tropical storm strikes northeastern Mexico
--> Category 2 hurricane strikes southern Baja California Peninsula
--> Hurricane threatens Hawaii but passes to south
--> Northwest Pacific active with four typhoons--several Asian nations
adversely affected
*************************************************************************
***** Feature of the Month for August *****
NOTE!!! The Feature of the Month was included in Part 1 of the
August summary.
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for August: 1 tropical depression
2 tropical storms **
1 major hurricane
** - Erika has been upgraded to minimal hurricane status in
post-storm analysis
Sources of Information
----------------------
Most of the information presented below was obtained from the
various tropical cyclone products issued by the Tropical Prediction
Center/National Hurricane Center (TPC/NHC) in Miami, Florida:
discussions, public advisories, forecast/advisories, tropical weather
outlooks, special tropical disturbance statements, etc. Some
additional information may have been gleaned from the monthly
summaries prepared by the hurricane specialists and available on
TPC/NHC's website. All references to sustained winds imply a
1-minute averaging period unless otherwise noted.
Atlantic Tropical Activity for August
-------------------------------------
Over the period 1950-2002, August has averaged 2.7 named storms, 1.5
hurricanes and 0.6 intense hurricanes. In terms of overall activity,
August, 2003, was a rather average month with 3 named storms, 1 hurricane
and 1 intense hurricane. Tropical Storm Erika formed on 14 August in the
eastern Gulf of Mexico from a disturbance of subtropical origin which
had traveled westward for several days from the Atlantic north of
Hispaniola. Erica sailed westward at an unusually rapid speed for a Gulf
of Mexico storm and made landfall in northeastern Mexico only two days
after its formation southwest of Tampa. Erica intensified fairly quickly
as it neared landfall and may possibly have been a minimal hurricane when
the center moved onshore.
Tropical Storm Grace formed in the western Gulf of Mexico on 30 August
and limped ashore in Texas as a minimal tropical storm the next day. The
main storm to form in August was mighty Hurricane Fabian. This large,
severe Cape Verde hurricane tracked westward for many days, eventually
recurving along a smooth, parabolic track which took the center just west
of Bermuda, bringing Category 3 hurricane conditions to the small island.
Fabian was the most intense hurricane to strike the British colony in
many decades and was rather destructive to the island.
One non-developing depression formed during August in the northeastern
Caribbean. A strong tropical wave entered the Caribbean on 20 August,
and the next day a ship reported a west wind south of the center. There-
fore, advisories were initiated on Tropical Depression 09 at 2100 UTC
with the poorly-defined center located approximately 225 nm south of San
Juan, Puerto Rico. The depression was expected to develop into a
tropical storm and be near hurricane strength in 96 hours. On the
morning of the 22nd, high-resolution visible satellite imagery indicated
that the depression was becoming better organized with a well-defined
cloud band to the north and east of the center and good outflow in all
quadrants except the west. However, a reconnaissance plane investigating
the system south of Santo Domingo in the afternoon could not find a
closed circulation, so the system was downgraded to a tropical wave.
Even so, the system had a vigorous mid-level circulation and a well-
defined cloud pattern in satellite imagery, and data T-numbers were 2.0
and 2.5 from the various satellite analysis agencies. Regeneration was
considered a possibility, but this never materialized.
NOTE: A short report on Tropical Depression 09, written by Lixion
Avila, can be found on TPC/NHC's website at the following URL:
<http://www.nhc.noaa.gov/2003nine.shtml?>
Also, additional reports on some of the other Atlantic tropical cyclones
of 2003 have already been placed on TPC/NHC's website:
<http://www.nhc.noaa.gov/2003atlan.shtml>
This installment of the August summary (Part 2) contains reports
on Hurricane Fabian and Tropical Storm Grace. Part 1 included the
report on Hurricane Erika (which was upgraded to a hurricane in post-
storm analysis.)
HURRICANE FABIAN
(TC-10)
27 August - 9 September
-------------------------------------------
NOTE: The official TPC/NHC storm report on Hurricane Fabian is now
available online at the following URL:
<http://www.nhc.noaa.gov/2003fabian.shtml?>
The very informative report was jointly authored by Richard Pasch,
Eric Blake and Dan Brown, and I would encourage all readers to access
this report. However, the report was not available until after I had
completed my summary of Fabian, so I am sending that one along as well.
A. Storm Origins
----------------
A large tropical wave moved off the west African coast on 24 August.
The Tropical Weather Outlook issued by TPC/NHC at 0930 UTC on the 25th
mentioned that the wave was located about 285 nm southeast of the Cape
Verde Islands, moving west at 13 kts, and that conditions appeared to
be favorable for further development. By the morning of 26 August a
well-defined surface LOW accompanying the wave was located approximately
225 nm southeast of the Cape Verdes. Convective activity had increased
near the center overnight and atmospheric conditions were believed to
be conducive for continued development. Convection gradually increased
in coverage and organization, and at 2100 UTC on the 27th, the first
advisory was issued on Tropical Depression 10, located about 415 nm west
of the southernmost Cape Verdes and moving westward at 17 kts with the
MSW estimated at 25 kts.
The intensity was upped to 30 kts at 28/0300 UTC based on T2.0 Dvorak
ratings from TAFB and SAB, plus data from a scatterometer pass.
Convection was beginning to take on a more banded appearance. The
depression remained somewhat disorganized early on the 28th--at least
three low-level swirls were being identified as centers--so the MSW
remained at 30 kts even though TAFB and SAB had bumped up their estimates
to 35 kts by 0600 UTC. During the day the cloud pattern's organization
improved with more prominent banding features and an increase in central
convection. With T-numbers ranging from 35 to 45 kts, the depression
was upgraded to Tropical Storm Fabian at 2100 UTC. The new tropical
storm was located about 870 nm west of the southernmost Cape Verdes and
moving quickly westward at 19 kts. The MSW was estimated at 40 kts,
and continued intensification was forecast with Fabian progged to reach
hurricane intensity in 72 hours.
B. Storm History
----------------
Tropical Storm Fabian intensified steadily as it moved rather quickly
westward across the Atlantic. By mid-morning on the 29th the cloud
pattern consisted of a cyclonically curved band which wrapped around the
center of circulation. A 29/0930 UTC SSM/I pass showed a ring of
convection associated with Fabian's center. T-numbers from all satellite
agencies had reached 3.5 by 1200 UTC, but the MSW remained at 50 kts on
the 1500 UTC advisory due to the ragged cloud pattern. During the after-
noon the convective signature and outflow continued to improve, and
Fabian was upgraded to a hurricane at 2100 UTC, only 24 hours after being
named as a tropical storm. Hurricane Fabian was located about 950 nm
east of the Lesser Antilles, and the westward motion had slowed down a
bit to 14 kts.
The season's third hurricane continued to intensify at a steady pace.
Early in the morning of 30 August Fabian was sporting cloud tops to
-80 C near the center with evidence of outer banding in the eastern semi-
circle. Winds were upped to 70 kts at 0900 UTC and further to 85 kts
at 1500 UTC, thus making Fabian a Category 2 hurricane on the Saffir/
Simpson scale. An eye feature was becoming apparent in visible images,
and by afternoon the eye was well-defined and surrounded by very deep
convection. T-numbers had reached 5.5, so at 2100 UTC Fabian's MSW was
increased to 100 kts, making the storm the first major hurricane of the
season only 72 hours after being classified as a tropical depression.
Hurricane Fabian was then located roughly 675 nm east of the Lesser
Antilles, moving westward at about 12 kts. During the evening the deep
convection became even more symmetric around a very tight 10-nm diameter
eye. Dvorak satellite intensity estimates from TAFB and AFWA had reached
6.0 by 31/0000 UTC, so the MSW was upped to 110 kts on the 31/0300 UTC
advisory. During the morning of the 31st the coldest cloud tops looked
a little ragged and the eye became obscured by the cirrus canopy for
a time, so the intensity remained pegged at 110 kts for 18 hours. But
by 2100 UTC the eye had become distinct again in both visible and infra-
red images, embedded within a perfectly round CDO and surrounded by
plenty of banding features. Therefore, the MSW was upped to 115 kts,
making Fabian a dangerous Category 4 hurricane on the Saffir/Simpson
scale. The hurricane was then centered about 435 nm east of the northern
Leeward Islands, moving west at 10 kts.
Monday, 1 September, was an exciting day in the life of intense
Hurricane Fabian. At 01/0300 UTC the MSW was raised slightly to 120 kts
based on an improved satellite signature and CI estimates of 127 kts from
TAFB and SAB, and 140 kts from AFWA. The eye had cleared out and warmed
significantly. Then, the first Air Force Hurricane Hunters
reconnaissance mission reached the hurricane around 0600 UTC. Peak winds
of 133 kts were measured at 700 mb, bolstering confidence in the 120-kt
surface MSW estimate. However, the lowest CP measured (949 mb) was not
quite as low as had been estimated in the 0300 UTC advisory (940 mb).
Another plane investigated Fabian in the afternoon around 1800 UTC and
found that the CP had dropped to 942 mb. Also, peak flight-level winds
of 140 kts were indicated, corresponding to 125 kts at the surface. The
2100 UTC discussion bulletin noted that eyewall convection had become
colder and more symmetric, and also that the outflow pattern had become
more symmetric since the morning. Fabian was now at its peak intensity--
a large, severe Category 4 hurricane located 240 nm east-northeast of the
island of Barbuda in the northern Leewards, moving west-northwestward
at 10 kts. Hurricane-force winds extended outward 45 nm in all quadrants
except the southwest, and gales reached outward 120 nm in the northern
quadrants and 75 nm to the south.
During 2 September Fabian's track gradually bent more to the right--by
2100 UTC the cyclone was moving between west-northwest and northwest at
9 kts. The intensity remained basically static--the MSW was lowered
slightly to 120 kts at 0900 UTC based on reconnaissance data. Satellite
intensity estimates came down a bit during the day to 102-115 kts, but
the 1800 UTC reconnaissance plane found peak 700-mb winds of 130 kts,
which supported 115-120 kts at the surface. Two NOAA P-3 aircraft found
105 kts at the surface in the northwest eyewall with the Stepped
Frequency Microwave Radiometer, but at advisory time had not sampled the
stronger northeastern quadrant. The eye diameter had increased to 30 nm
from 20 nm the previous day. Late on the 2nd Fabian was making its
closest approach to the Leeward Islands, being centered at 2100 UTC about
185 nm north-northeast of Barbuda. A NOAA P-3 aircraft made an eye
penetration around 02/2221 UTC and found a 700-mb FLW of 125 kts and a CP
of 944 mb, so the MSW was reduced slightly to 115 kts at 03/0300 UTC.
The inner-core convection had also weakened and become more ragged in
appearance. Some westerly shear was also beginning to affect Fabian as
evidenced by a lack of cirrus outflow over the western semicircle. The
eye had also become somewhat ragged in satellite images and the Hurricane
Hunters reported that it had taken on an elliptical shape, although it
was still surrounded by a ring of deep convection. At 03/2100 UTC the
center of Hurricane Fabian was located about 575 nm south of Bermuda,
moving northwest at 8 kts. Based on lower T-numbers and findings from
USAF and NOAA reconnaissance aircraft, the MSW was lowered to 105 kts,
placing Fabian back in Category 3 status.
For days Fabian had been moving along the southern periphery of the
subtropical ridge, and by late on the 3rd was located on the southwestern
edge of the ridge. With a large trough over the eastern U. S., recurv-
ature to the north and then northeast was forecast. The projected track
was pointing to Bermuda as a likely target of Fabian, and accordingly
at 0900 UTC on 4 September, the Bermuda Weather Service issued a hurri-
cane watch for the island. At 0900 UTC the hurricane was centered about
500 nm south of the island and moving north-northwest at 7 kts. A NOAA
P-3 aircraft made an eye penetration at 03/2245 UTC and found a 738-mb
FLW of 127 kts in the north quadrant along with a CP of 939 mb. Also,
an eyewall dropsonde reported a wind speed of 142 kts at 28 m above the
surface. Based on this information, the MSW was upped to 110 kts in the
04/0300 UTC advisory. However, a few hours later data from a Hurricane
Hunters' mission indicated some weakening, so the MSW was reduced to
105 kts once more at 0900 UTC.
During the morning of 4 September Fabian's outflow became better
established as the upper-level LOW northeast of the Bahamas weakened.
This LOW had been responsible for the unfavorable shear over the storm
on the previous day. The intensity was held at 105 kts during the day,
but at 0000 UTC on the 5th was upped to 110 kts again. Two eyewall drops
between 04/2000 and 2200 UTC had indicated surface winds of 111 and 114
kts, and the CP was measured at 940 mb. At 05/0300 UTC Hurricane Fabian
was centered 260 nm south of Bermuda, and the storm was now moving almost
due northward at a faster pace of 15 kts. The storm had continued to
grow in size, and winds to hurricane force reached outward 100 nm to the
northeast of the eye and 75 nm to the southeast and northwest while gales
covered an area over 300 nm in diameter. A reconnaissance plane in the
storm around 0600 UTC reported a CP of 948 mb and 110 kts for a peak FLW,
so the MSW was reduced back to 105 kts at 0900 UTC. The eye was 40 nm
in diameter and circular, but as the morning progressed the eye became
elongated. The 1200 UTC reconnaissance flight found a peak FLW of 118
kts and a CP of 951 mb, so it appeared Fabian was maintaining its MSW
of 105 kts. During the afternoon the center of severe Hurricane Fabian
passed just west of Bermuda, bringing the intense east eyewall directly
over the island. Observations from Bermuda (see Section C below)
indicate that the hurricane struck the island as a major Category 3
hurricane on the Saffir/Simpson scale--the strongest hurricane to
strike the island since 1926.
By 0300 UTC on 6 September Fabian was centered about 110 nm north-
northeast of Bermuda and was moving northeastward at about 17 kts.
Recent observations from Bermuda indicated winds in the 50-60 kt
range (made with a hand-held anemometer due to the destruction of the
normal wind measuring equipment). By 0900 UTC winds had dropped to
just below gale force on the island as Fabian continued to pull away
toward the northeast. The MSW was dropped to 95 kts at 1500 UTC, but
even during the afternoon Fabian remained a well-organized hurricane
with a distinct eye surrounded by deep convection and good outflow.
The MSW remained at 95 kts in the 2100 UTC advisory, and the forecaster
noted that this could be conservative. However, Fabian's intensity
began to steadily decline on the 7th. The 07/0900 UTC discussion noted
that Fabian was beginning to feel the effects of the upper-level
westerlies with some shearing evident. Satellite intensity estimates
were in the 80-90 kt range, so the intensity was adjusted to 85 kts.
Weakening continued with Fabian crossing the 25 C isotherm during the
late morning of the 7th. Central convection was less intense and the
hurricane displayed a southeast-northwest elongated appearance in
satellite imagery. By late afternoon a small core of deep convection
remained near Fabian, but satellite imagery revealed a frontal tail
forming on the southeastern side of the cyclone along with cold-air
stratocumulus clouds wrapping into the southwest quadrant, signifying
that Fabian was beginning extratropical transition. The MSW was further
decreased to 75 kts at 07/2100 UTC, and Fabian was forecast to be fully
extratropical in 24 hours. The weakening hurricane was then located
approximately 250 nm southeast of Cape Race, Newfoundland, and moving
quickly northeastward at 27 kts over SSTs below 21 C.
Convection continued to decrease in coverage and intensity early on
8 September as the low-level circulation gradually became exposed.
Enhanced infrared imagery and a 08/0008 UTC SSM/I pass depicted an
asymmetric structure with a very small area of deep convection confined
to the northwest quadrant. By 0900 UTC the LLCC had become fully-exposed
and the MSW was reduced to 65 kts, based on an intensity estimate from
TAFB. (AFWA and SAB had estimated the intensity as an extratropical
system.) By 1500 UTC satellite images indicated there was no deep
convection below -50 C near the center of Fabian, and cold-air strato-
cumulus clouds had infiltrated the core of the cyclone. TPC/NHC issued
the final advisory on Fabian at this time, placing the center almost
600 nm east-northeast of Cape Race and moving northeastward at 34 kts.
Water temperatures were near 15 C and the storm was rapidly becoming
fully extratropical. The final advisory intensity was kept at 65 kts
due to a late-arriving buoy report of 70-kt winds at 0700 UTC. The
extratropical Fabian continued moving northeastward, gradually turning
northward toward Greenland on the 9th. After 11/0000 UTC the LOW began
moving toward the east, crossing southern Iceland on the 12th. It was
last noted moving northward once again to the east of Iceland later
on 12 September.
C. Meteorological Observations
------------------------------
Other than the buoy report referenced in the final paragraph in
Section B, all the surface observations from Hurricane Fabian were
reported from Bermuda. At 05/1800 UTC the Bermuda Weather Service
relayed an observation of a sustained wind of 75 kts and a peak gust of
87 kts from Bermuda Harbor Radio. Around 05/2000 UTC the Bermuda Air-
port estimated sustained winds at 91 kts with a peak gust of 116 kts.
The highest reported wind was an unofficial report from Bermuda Harbor
Radio around 05/2100 UTC of a sustained wind of 102 kts and a peak gust
of 110 kts. This latter observation was made shortly before the 76 metre
instrumented mast blew down. The Bermuda Airport also recorded a SLP
of 965.5 mb during the afternoon of the 5th.
D. Damage and Casualties
------------------------
Damage in Bermuda was extensive. A preliminary estimate placed the
total at around $300 million (US). The hurricane was also responsible
for eight deaths: four fatalities on Bermuda, three fishermen who
drowned off Newfoundland, and a rip current drowning near Cape Hatteras.
(Report written by Gary Padgett)
TROPICAL STORM GRACE
(TC-11)
30 August - 2 September
-------------------------------------------
A. Storm Origins
----------------
A tropical wave left the coast of western Africa during the third
week of August. A Tropical Weather Outlook issued by TPC/NHC at 1530
UTC on 21 August indicated that an area of disturbed weather associated
with a tropical wave had developed in the Atlantic midway between Africa
and the Lesser Antilles. The system was moving westward at 13 kts and
conditions were only marginally favorable for further development. By
the morning of the 23rd the wave was 825 nm east of the Windward Islands,
and satellite imagery indicated that showers had increased some since
the previous day. Also, upper-level conditions were becoming a little
more favorable for development. A Tropical Weather Outlook on the
morning of 24 August described the system as a large, complex tropical
wave located about 520 nm east of the Lesser Antilles. The southern
portion of the wave had become a little better organized, and convection
was seen to increase even more during the afternoon.
Early on the 25th the wave was moving across the Lesser Antilles and
into the extreme eastern Caribbean Sea. By afternoon of the 26th the
system was producing showers and thunderstorms over Hispaniola and
eastern Cuba. Surface pressures were low, but upper-level winds were
not favorable for development. On 27 August cloudiness and showers
associated with the wave diminished and the system consisted of a very
broad area of low pressure extending from the northwestern Caribbean
across Cuba and into the Bahamas. A Tropical Weather Outlook from
TPC/NHC around midday on the 28th noted that cloudiness and showers
had become more concentrated over the northwestern Caribbean. By
late afternoon the area had become better organized with a large area
of showers spreading over the Cayman Islands, western Cuba and the
Yucatan Channel. The system was forecast to move into the Gulf of
Mexico in a day or two where upper-level conditions would be more
conducive to tropical cyclone development.
By 29 August the disturbance had moved into the southern Gulf of
Mexico with little change in organization as it moved slowly northwest-
ward. At 1315 UTC on the 30th, a Special Tropical Disturbance State-
ment was issued by TPC/NHC. Surface observations and high resolution
visible images indicated that a tropical depression appeared to be
forming in the Gulf. The first advisory on Tropical Depression 11 was
issued at 1500 UTC, placing the poorly-defined center about 300 nm east-
southeast of Corpus Christi, Texas. TD-11 was moving northwestward at
10 kts, and the initial intensity was set at 30 kts. Tropical storm
warnings were issued from High Island, Texas, to Corpus Christi.
An intermediate bulletin at 1800 UTC indicated that TD-11 was nearing
tropical storm strength, and that a reconnaissance plane was approaching
the system. At 2100 UTC the depression was upgraded to Tropical Storm
Grace, located about 245 nm east-southeast of Corpus Christi and moving
west-northwestward at 8 kts. The maximum 450-metre FLW reported was
43 kts, corresponding to about 34 kts at the surface, and there were also
some reports from ships and oil platforms of tropical storm-force winds
well to the northeast of the broad center. The discussion bulletin noted
that upper-level outflow was good in the eastern semicircle but somewhat
restricted to the west.
B. Storm History
----------------
A reconnaissance flight into Grace during the evening hours found a
very poorly-defined system. Indeed, as the 31/0300 UTC discussion
bulletin noted, it was a stretch to call it a tropical cyclone. Grace
was more of a north-south oriented trough with pressures 150 nm north
of the center about the same as near the supposed center. The plane
found a FLW of only 40 kts at 450 metres, but a ship reported surface
winds of 36 kts at 31/0000 UTC about 180 nm northeast of the center.
The 0000 UTC reconnaissance flight found multiple, poorly-defined
centers within a larger elongated circulation. The 0900 UTC advisory
position, about 100 nm southeast of Corpus Christi, was a compromise
between aircraft and surface observations as well continuity from the
previous advisory. An upper-level LOW in the vicinity of Brownsville
was inhibiting strengthening of the tropical cyclone.
Grace was downgraded to a tropical depression at 31/1500 UTC with the
center of the elongated trough near the Texas coast near Port O'Connor.
The highest wind observed shortly before advisory time was 30 kts at
the Sabine Pass CMAN Station. At 1300 UTC the lowest reported MSLP was
1008.6 mb near Galveston, but at 1200 UTC Buoy 42019 reported 1008.7 mb.
The center position was kept south near the buoy, but the advisory noted
that it could just as well have been placed 100 miles further north near
Galveston. The center position was not particularly important since
the strongest winds and heaviest rains extended well north and east of
the center. The 1500 UTC advisory was the final one issued by TPC/NHC.
Future releases on the weakening remnants of Grace became the
responsibility of the Hydrometeorological Prediction Center (HPC),
located at Camp Springs, Maryland. Tropical Depression Grace moved
slowly northwest over eastern Texas, later turning toward the northeast.
By the time of the issuance of the final HPC summary at 0900 UTC on
2 September, Grace's remnant LOW had merged with a stationary front
and was located about 120 km west-northwest of Hot Springs, Arkansas.
C. Rainfall Measurements
------------------------
Some selected rainfall amounts resulting from Tropical Storm Grace
and/or the combination of Grace's remnants and the stationary front
include:
Station Rain (mm) Time Period (UTC)
----------------------------------------------------------------------
Beaumont/Port Arthur, TX 72 24 hrs ending Aug 31 1800
Galveston, TX 69 Total through Sep 01 0000
Beaumont/Port Arthur, TX 124 Total through Sep 01 0600
Houston Clover Field, TX 107 Total through Sep 01 0600
Houston Clover Field, TX 85 24 hrs ending Sep 01 1200
Houston Hobby, TX 85 24 hrs ending Sep 01 1800
Terre Haute, IN 119 24 hrs ending Sep 02 0000
Huntsville, TX 84 30 hrs ending Sep 02 0600
Jefferson City, MO 99 30 hrs ending Sep 02 0600
Indianapolis, IN 187 30 hrs ending Sep 02 0600
Lafayette, IN 92 30 hrs ending Sep 02 0600
The above rainfall information was obtained from the HPC storm
summaries.
D. Damage and Casualties
------------------------
No reports of damage or casualties resulting from Tropical Storm Grace
have been received.
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for August: 1 tropical depression
2 tropical storms
2 hurricanes
Sources of Information
----------------------
Most of the information presented below was obtained from the
various tropical cyclone products issued by the Tropical Prediction
Center/National Hurricane Center (TPC/NHC) in Miami, Florida (or the
Central Pacific Hurricane Center (CPHC) in Honolulu, Hawaii, for
locations west of longitude 140W): discussions, public advisories,
forecast/advisories, tropical weather outlooks, special tropical
disturbance statements, etc. Some additional information may have
been gleaned from the monthly summaries prepared by the hurricane
specialists and available on TPC/NHC's website. All references to
sustained winds imply a 1-minute averaging period unless otherwise
noted.
Northeast Pacific Tropical Activity for August
----------------------------------------------
Over the period 1971-2002, August has averaged 4.0 named storms, 2.4
hurricanes and 1.2 intense hurricanes. August, 2003, was pretty close
to normal with 4 named storms, 2 hurricanes and no intense hurricanes.
Tropical Storm Ignacio reached hurricane intensity on 24 August--the
latest starting date for the first hurricane of the season since the
beginning of the modern satellite era. Tropical Storms Guillermo and
Hilda formed during the second week of the month well southwest of
Mexico and were rather insignificant. Ignacio strengthened into a
Category 2 hurricane and moved up into the Gulf of California, passing
east of Cabo San Lucas. The hurricane grazed the coast near La Paz
and later moved inland on the peninsula northwest of La Paz, subsequently
dissipating over the mountainous terrain. Hurricane Jimena, forming
far to the west, also became a Category 2 hurricane and was beginning to
pose a threat to the Big Island of Hawaii, but as it approached the
island, weakened and turned to the west-southwest.
The only non-developing depression during the month formed in the
Honolulu AOR west of 140W. A disturbance which had been followed for
several days had acquired enough convective organization to be classified
as a tropical depression by the 15th. Advisories were initiated on
Tropical Depression 01C at 2100 UTC, placing the center approximately
475 nm southeast of Hilo. Almost immediately after being classified,
convection died down rather significantly. The discussion bulletin at
16/0900 UTC noted that the depression was a marginal system with an
elongated shape and several vorticity centers. By 17/0000 UTC the
depression had become too weak to be properly classified and was down-
graded to a disturbance at 0300 UTC when located roughly 350 nm south-
southwest of Hilo. An exposed vortex center was visible, but there was
no evidence of westerly winds on the south side of the system. Deep
convection was located far to the east and the vortex was forecast to
move into an even more hostile environment.
Additional reports on some of the other Eastern Pacific tropical
cyclones of 2003 have already been placed on TPC/NHC's website:
<http://www.nhc.noaa.gov/2003epac.shtml>
This installment of the August summary (Part 2) contains a summary
of Hurricane Jimena, and a brief report on Hurricane Ignacio (the
official TPC/NHC storm report on this cyclone is already available
online). Part 1 carried reports on Tropical Storms Guillermo and
Hilda.
HURRICANE IGNACIO
(TC-09E)
22 - 27 August
-------------------------------------
NOTE: The official TPC/NHC storm report on Hurricane Ignacio,
authored by Miles Lawrence, is now available at the following
URL:
<http://www.nhc.noaa.gov/2003ignacio.shtml?>
Since the official storm report is already available online, there
is no need of my writing a preliminary report on the system, so my
comments here will be brief.
Tropical Depression 09E formed on 22 August southeast of the tip
of the Baja California Peninsula, was upgraded to Tropical Storm
Ignacio the next day, and at 0600 UTC on 24 August became the first
hurricane of the 2003 Eastern North Pacific season. This represents
the latest date for the appearance of the first hurricane in this
basin since the beginning of the modern satellite era in 1966. The
only other year in which the first hurricane did not put in its
appearance until August was in 1968, when Hurricane Fernanda became
that season's first hurricane on 8 August (according to the Best
Track file). Also, 2003 was the first year not to produce a July
hurricane since 1972.
Ignacio followed a slow north-northwesterly track which carried
it just east of Cabo San Lucas on the tip of the Baja and later inland
on the Peninsula just north of La Paz. Heavy rainfall, enhanced by
the storm's slow movement, was the primary destructive agent in
association with Hurricane Ignacio. Miles' report indicates that
two persons were drowned as a result of the hurricane.
For more information on Ignacio, please see the report at the
link given above.
HURRICANE JIMENA
(TC-10E)
28 August - 5 September
-------------------------------------------
A. Storm Origins
----------------
A Tropical Weather Outlook issued by TPC/NHC at 1100 UTC on 27 August
mentioned a broad area of disturbed weather located roughly 1130 nm
southwest of the southern tip of the Baja California Peninsula (Cabo
San Lucas). The disturbed weather was poorly organized but there was
some potential for further development. By very early on the 28th the
system was located about 1215 nm west-southwest of Cabo San Lucas and
had become much better organized. The first advisory on Tropical
Depression 10E was issued at 0900 UTC, locating the center approximately
1250 nm west-southwest of Cabo San Lucas and moving westward at 10 kts.
Convection was concentrated near the center and outflow was good in all
directions. Six hours later satellite classifications had reached a
consensus of T2.5, or 35 kts, but since a TRMM microwave pass at 28/0841
UTC had suggested that the LLCC might be displaced north of the center
position inferred from infrared imagery, the forecaster opted to hold
off upgrading the cyclone for the moment.
B. Storm History
----------------
By 2100 UTC, however, CI estimates from TAFB and SAB had reached 45
kts, so TD-10E was upgraded to Tropical Storm Jimena. The new tropical
storm was then located about 1350 nm west-southwest of Cabo San Lucas,
or roughly 1375 nm east-southeast of Hilo, Hawaii. Jimena continued
to intensity steadily as evidenced by increased banding of cold
convection and the occasional appearance of an eye-like feature. At
29/0000 UTC satellite intensity estimates were 55 kts from TAFB, 45 kts
from SAB and Honolulu, and 35 kts from AFWA; hence, at 0300 UTC the
MSW was jumped up to 50 kts. A 29/0556 UTC SSM/I pass revealed a well-
defined eye under the concentrated cold convection, so the MSW was upped
again to 55 kts at 0900 UTC. Six hours later, Jimena was upgraded to the
second hurricane of the 2003 season based on CI estimates ranging from
55 kts to 77 kts, plus a 29/0932 UTC TRMM pass which had revealed a
small distinct eye embedded in the deep convection. Newly-upgraded
Hurricane Jimena was located about 1125 nm east-southeast of Hilo, moving
west-northwestward at 14 kts. The west-northwesterly motion was
attributed to a weakness in the subtropical ridge induced by a mid to
upper-level trough north of Hawaii. This ridge was expected to lift out
and allow the ridge to become re-established, leading to a more westward
track for Jimena in about 24 hours.
The last few visible images on 29 August showed a very tight eye only
10 nm in diameter which was partially cloud-filled. Based on Dvorak
intensity estimates of 90 kts from TAFB and AFWA, Jimena's intensity was
upped to 85 kts at 30/0300 UTC. Since the hurricane was moving along the
26 C SST isotherm and would soon be entering cooler waters, it was felt
that the intensity would level off for 24 hours or so with a gradual
weakening beginning thereafter. The final TPC/NHC advisory issued at
0900 UTC maintained the 85-kt MSW, based on intensity estimates ranging
from 77 kts to 102 kts. Since the hurricane's center had moved west
of 140W, the Central Pacific Hurricane Center (CPHC) located in Honolulu
assumed responsibility for issuing advisories on Jimena. In spite of
its passage over SSTs slightly cooler than 26 C, persistent Dvorak
estimates of 5.0 from Honolulu and even higher AFWA estimates prompted
CPHC to raise the MSW to 90 kts at 2100 UTC--the peak for the storm's
history. (The minimum estimated CP for Jimena was 970 mb.) At the
time the center of Jimena's well-defined eye was located approximately
735 nm east-southeast of South Point on the Big Island of Hawaii, moving
almost due westward at 17 kts. An immediate slow weakening was fore-
cast, yet Jimena maintained the 90-kt peak intensity for 24 hours.
With the hurricane's persistent rather rapid westerly motion in the
direction of Hawaii, a hurricane watch was issued for the Big Island in
a special advisory at 31/0000 UTC, followed by a tropical storm warning
for the island three hours later. As the 31st progressed Jimena began
to encounter some slight south-southwesterly shear which caused the storm
to gradually show signs of weakening. The MSW remained at 90 kts
through the 1500 UTC advisory based on the higher of the available Dvorak
estimates, but at 2100 UTC the intensity was reduced to 85 kts. The
hurricane's eye was not apparent in visible imagery, and the system was
becoming somewhat elongated. The weakening trend became more pronounced
on 1 September with Jimena being downgraded to a 60-kt tropical storm at
1500 UTC when located about 150 nm south of Hilo. The highest FLW found
by a reconnaissance aircraft was 55 kts. The hurricane watch for the
Big Island was also cancelled at this time. Jimena's track had also
taken a turn to the west-southwest, meaning that the likelihood of the
storm's striking the Big Island was further reduced. The closest
approach of Jimena to the island occurred around 01/1200 UTC when the
center was located about 100 nm southeast of South Point.
Jimena quickly fell apart after passing south of the Big Island--by
1500 UTC on 2 September the system had weakened to minimal tropical storm
intensity of 35 kts. Sporadic bursts of convection were occasionally
seen, but the general trend was that of weakening. By 0900 UTC on the
3rd Dvorak T-numbers were 2.0 or lower from all the applicable agencies,
so Jimena was reduced to tropical depression status. The depression's
center was placed approximately 300 nm east-southeast of Johnston Atoll.
The MSW was decreased further to 25 kts at 03/1500 UTC, where it remained
for 24 hours. Jimena continued to maintain a good peripheral cloud
circulation and some convection near the center. As the depression moved
farther west, shear decreased and Jimena began to show signs of life once
more. The MSW was boosted slightly to 30 kts at 04/1500 UTC as the
system exhibited some intense deep convection in the central core region.
With most Dvorak classifications at 2.5 at 1200 UTC, Jimena was
upgraded once again to minimal tropical storm status at 04/2100 UTC when
located about 375 nm west-southwest of Johnston Atoll. The center was
relocated somewhat further to the south of the previous advisory's
position. Most of the intensity models were rather enthusiastic for
some continued modest strengthening over the next 48 hours, but this was
not to be. By 05/0300 UTC Jimena's cloud and convective structure had
become quite ragged, and the convection had weakened with cloud tops
10 C warmer than six hours previously. All Dvorak classifiers rendered
a final T-number of 2.0, but due to constraints, Jimena was retained as
a tropical storm for one more advisory cycle. A developing upper-level
LOW was inducing increased shear over the tropical cyclone. By 0900 UTC
the weakening cyclone was moving across the International Dateline and
CPHC downgraded it back to a 30-kt tropical depression and issued their
final warning.
JTWC issued the final two warnings on Jimena. The MSW was further
lowered to 25 kts at 05/1200 UTC. A 05/0914 UTC SSM/I pass showed that
the LLCC was completely exposed with convection occurring far to the
south of the circulation center. A 05/1727 UTC TRMM pass indicated
that the LLCC had nearly dissipated. The final JTWC warning was issued
at 1800 UTC, placing the dissipating center about 500 nm northeast of
Majuro Atoll in the eastern Marshall Islands, or approximately 715 nm
east-southeast of Wake Island.
C. Damage and Casualties
------------------------
No reports of any damage or casualties resulting from Hurricane
Jimena have been received.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for August: 4 tropical depressions **
1 tropical storm
4 typhoons ++
** - one classified as a tropical depression by some of the Asian TCWCs
but not by JTWC, and as a tropical storm by PAGASA; another
referred to as a tropical depression only in a CPHC satellite
bulletin; two others classified as depressions by CWBT (one of
these by JMA also)
++ - one of these classified as a typhoon by JTWC only
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Michael V. Padua of Naga City in the Philippines, owner of the
Typhoon 2000 website, normally sends me cyclone tracks based upon
warnings issued by the Japanese Meteorological Agency (JMA) and the
Philippines' Atmospheric, Geophysical & Astronomical Services
Administration (PAGASA). Also, Huang Chunliang of Fuzhou City, China,
sends me each month tracks obtained from warnings issued by the
National Meteorological Center of China (NMCC), the Central Weather
Bureau of Taiwan (CWBT) and the Hong Kong Observatory (HKO). A very
special thanks to Michael and Chunliang for the assistance they so
reliably provide.
In the title line for each storm I have referenced 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 warning responsibility.
The reports on Typhoon Krovanh/Nina, Tropical Storm Vamco/Manang,
and Typhoon Dujuan/Onyok were written by Kevin Boyle. Significant
portions of these reports, as well as most of the information on
Tropical Depression Lakay, were based on information supplied by
Huang Chunliang. A special thanks to Kevin and Chunliang for their
contributions.
Northwest Pacific Tropical Activity for August
----------------------------------------------
August was a very active month in the Northwest Pacific basin. Five
tropical cyclones were named by JMA--four of these became typhoons per
JTWC's analysis. Another system was named by PAGASA and was upgraded to
a minimal tropical storm by that agency, although no other warning center
did so. Typhoon Morakot formed early in the month east of Luzon and
followed a northwesterly track which carried it across southern Taiwan
and into China. JTWC was the only agency which classified Morakot as a
typhoon. NMCC upgraded it to severe tropical storm status (winds > 47
kts), but none of the other TCWCs estimated the MSW any higher than 45
kts. Also during the first week of August, much-stronger Typhoon Etau
formed well to the east of the southern Philippines and followed a
typical recurving track to the east of Taiwan which carried it over
Okinawa and later over Japan, first striking Shikoku and later Honshu.
Typhoon Krovanh, known as Nina ("NEEN-yah") in the Philippines, took
shape very slowly around mid-month in the Philippine Sea. Once the
depression finally developed into a tropical storm, it followed a some-
what unusual west-southwesterly track before turning westward across
northern Luzon as a typhoon of moderate intensity. After emerging into
the South China Sea, Krovanh turned to the west-northwest and regained
intensity, passing just off northeastern Hainan Dao before striking
the Luichow Peninsula. Krovanh emerged into the Gulf of Tonkin and
made a final landfall in extreme northern Vietnam. Minor Tropical
Storm Vamco formed east of Taiwan and moved northwestward into China,
passing just off the northern tip of Taiwan.
Finally, late in the month, Typhoon Dujuan (named Onyok by PAGASA)
formed west of Guam and followed a fairly straight west-northwesterly
track which carried it through the Luzon Strait south of Taiwan and
into southern China near Hong Kong. Dujuan became a strong typhoon
and neared super typhoon intensity (per JTWC) as it passed just off
Taiwan's southern tip.
Another South China Sea system was classified as a tropical depression
by several of the Asian TCWCs--though not by JTWC--and was assigned the
name Lakay by PAGASA. Since Lakay was treated as a minimal tropical
storm by PAGASA, and since it caused some enhanced rainfall in China
as it dissipated, a short report will be included on this system.
Huang Chunliang has advised me of two additional tropical disturbances
which were treated as weak tropical depressions by some of the Asian
TCWCs. A disturbance which took shape during the final two days of
July several hundred miles east-northeast of Saipan was carried as a
weak tropical depression (MSW of 25 kts or less implied) by JMA in the
summary portion of that agency's High Seas Forecasts. JTWC gave this
system a fair potential for development, but dissipated it in their STWO
on 2 August. The CWB of Taiwan also upgraded this LOW to depression
status. Another disturbance located to the west of the pre-Etau system
was briefly classified as a tropical depression by CWBT on 2 August.
Apparently, at one point this system and the one which ultimately became
Etau were competing for inflow, but the eastern system won and developed
into Typhoon Etau.
This installment of the August summary (Part 2) contains reports on
Typhoons Krovanh and Dujuan as well as Tropical Storm Vamco. A short
report is also included on a tropical depression (classified as Tropical
Storm Lakay by PAGASA). Typhoons Morakot and Etau were covered in Part
1 of the August summary.
TYPHOON KROVANH
(TC-12W / TY 0312 / NINA)
14 - 26 August
---------------------------------------------
Krovanh: contributed by Cambodia, is the name of a type of tree
and also the name of a mountain
Nina: PAGASA name, is a female name (Spanish for small girl)
A. Storm Origins
----------------
At 2300 UTC on 13 August an area of convection had persisted near
6.9N, 155.3E ,or approximately 200 nm east of Chuuk, and this activity
was first noted on a STWO issued by JTWC at this time. The chances for
development were assessed as fair, based on low-level cloud lines
consolidating near a possible LLCC. An upper-level LOW was providing
good outflow aloft and wind shear over the area was light. Convection
associated with the suspect area continued to organise through the 14th,
although the aforementioned upper-level LOW was suppressing activity in
the northwestern quadrant. However, this feature was expected
to fill during the next 24 hours, further increasing the opportunity for
the development of a tropical cyclone. This was indicated in a TCFA
issued by JTWC at 14/2000 UTC. By this time the disturbance had moved
northwestward to a position approximately 85 nm northeast of Chuuk (near
6.8N, 154.7E). The potential for development remained good at 14/2100
UTC, and the STWO written at that time stated that the first warning
would soon follow. (Note: JMA began classifying the system as a 30-kt
(10-min avg) tropical depression at 14/0600 UTC, the time of their
first bulletin.)
The first warning on Tropical Depression 12W at 15/0600 UTC quickly
superceded the STWO issued at that time. The newly-formed tropical
depression was then located 370 nm east-southeast of Guam and moving
west-northwestward at 13 kts toward the island. This first warning
mentioned a second partially-exposed LLCC located to the southeast of
the deep convection and the primary centre being tracked. There was no
further mention of this attendant circulation, and deep convection waned
somewhat during the next six hours. Most of the convective activity had
been occurring in the northern semicircle with short bursts over the
LLCC. An increase in convection over the southern quadrants was noted
in multi-spectral satellite animations at 16/0600 UTC. The warning
position at this time was based on enhanced infrared satellite imagery
which located the centre approximately 160 nm east-southeast of Guam
(near 11.6N, 148.0E.)
By 16/1800 UTC Tropical Depression 12W was approaching Guam, being
located 90 nm to the east-southeast. Six hours later the system had
made its closest approach to Andersen AFB and was centred 30 nm to the
northwest. The depression continued to organise during this period,
and a 16/2332 UTC SSM/I pass depicted deep cycling convection beginning
to consolidate over the LLCC. However, there were no other indications
that strengthening was occurring. In fact, a QuikScat pass at 17/0833
UTC showed no evidence of a LLCC but rather an area of convergence near
the deep convection. Animated satellite imagery suggested that the
convection was associated with a mid-level circulation. Moving away
from Guam on a west-northwesterly to northwesterly track, TD-12W failed
to show any signs of an identifiable LLCC, and the 17/1800 UTC position
(approximately 195 nm northwest of Andersen AFB, Guam) had to be
determined by extrapolation of previous positions plus the apparent
centre of the deep cycling convection. Based on the lack of a proper
LLCC, JTWC opted to discontinue warnings at 18/0000 UTC. (JMA issued
warnings for a further 18 hours before that agency also discontinued
bulletins.)
JTWC included the remnants of Tropical Depression 12W in their STWOs
through the 18th, assessing redevelopment potential as poor at 0600 UTC,
then upgrading to fair at 1000 UTC. UW-CIMSS chart analysis showed
light wind shear conditions and fair to moderate diffluence aloft.
Early on the 19th, animated multi-spectral satellite imagery revealed
an exposed LLCC north of the deep convection, which had increased in
areal extent. This was a step in the right direction for the tropical
cyclone, and at 19/0600 UTC JTWC indicated in an STWO that the system
would be re-designated as a tropical depression and warnings restarted
within 6 to 12 hours. Warnings were initiated at short notice, (i.e.,
at 19/0900 UTC) and the regenerated depression's initial position was
approximately 530 nm southeast of Okinawa, or 20.9N, 135.5E. Deep
convection had increased over the LLCC, although a 19/1155 UTC SSM/I
pass showed decreased convection in the northwestern quadrant of TD-12W,
possibly due to some kind of interaction with the developing Tropical
Storm Vamco located to the northwest. (JMA began re-issuing warnings
at 19/1800 UTC although there was a reference to the system in the
19/1200 UTC bulletin.)
At 0000 UTC on 20 August Tropical Depression 12W was centred approxi-
mately 440 nm southeast of Okinawa, Japan, and moving westward at 7 kts.
Recent microwave satellite imagery revealed a partially-exposed LLCC
north of the deep convection. The heading turned west-southwesterly at
0600 UTC as the system became a 35-kt tropical storm, and toward the
southwest six hours later as TS-12W became a named tropical cyclone when
JMA upgraded the system to a 35-kt tropical storm (10-min avg). Newly-
christened Tropical Storm Krovanh reverted back to a westerly heading
as it strengthened to 45 kts at 1800 UTC.
(Krovanh also had another name: Nina. This was PAGASA's internal
name, used after that agency began writing warnings at 20/0000 UTC.
NMCC began issuing statements at 20/1200 UTC while the remaining Asian
warning agencies--HKO and CWBT--began writing warnings at 22/0000 UTC.)
B. Storm History
----------------
The MSW had increased to 60 kts by 0000 UTC on the 21st and Krovanh
was on the verge of becoming a typhoon. A banding eye was seen but the
deepest convection was occurring mainly in the southern sectors. A
Prognostic Reasoning message issued at this time suggested further
intensification at a climatological rate until the storm made its
initial landfall on Luzon. The extended forecast also suggested a
possible landfall north and east of Hong Kong within approximately
84 hours. Krovanh became a 65-kt typhoon at 21/0600 UTC, although an
earlier 21/0142 UTC AMSU pass showed that the mid-level circulation
was slanted to the west of the LLCC. Also, animated satellite imagery
depicted the deep convection being sheared to the southwest due to an
upper-level LOW to the northeast propagating west toward Krovanh and
interfering with the poleward outflow pattern. Undaunted, the cyclone
strengthened further with the MSW increasing to 75 kts at 1800 UTC.
Microwave imagery at this time revealed a developing asymmetric eye
averaging 15 nm in diameter.
At 0000 UTC on 22 August Typhoon Krovanh was located approximately
220 nm east of Luzon, having moved back to a west-southwesterly
heading. Recent 21/2350 UTC SSM/I imagery showed a ragged 20-nm
asymmetrical eye, although this feature was not apparent in visible or
infrared satellite imagery. The intensity had increased to 90 kts with
a 10-min avg MSW of 65 kts as estimated by JMA resulting in an upgrade
to typhoon status by that agency. By 0600 UTC all agencies were
monitoring Krovanh/Nina as a typhoon. During the 22nd Typhoon Krovanh/
Nina steadily approached Luzon and made landfall at approximately
22/1115 UTC just north of Palanan. The MSW was estimated at 80 kts with
gusts to 100 kts. During its passage across Luzon, Krovanh weakened
to 70 kts, and by 1800 UTC was about to move off the west coast of Luzon.
Six hours later, at 23/0000 UTC Typhoon Krovanh/Nina was tracking
west-northwestward over the warm waters of the South China Sea, centred
at this time approximately 65 nm west of Luzon. The Prognostic Reasoning
message issued at that hour forecast a continued west-northwesterly
heading under the influence of a low to mid-level steering ridge to the
north, and the typhoon was expected to make landfall on China's Leizhou
Peninsula in the 48-54 hour time frame. Krovanh was becoming better
organized but the MSW was not raised until 24/0000 UTC. By this time
the typhoon had moved to within approximately 220 nm south of Hong Kong
after trudging its way west to west-northwestward across the South China
Sea. (Krovanh/Nina had by now moved out of PAGASA's AOR. Both CWBT
and PAGASA ceased to issue warnings at 23/0600 UTC and 23/1200 UTC,
respectively.) Tightly-curved banding features as well as a banding-
type eye were once again evident in satellite images. Intensity
fluctuated during the next day or so with the MSW reaching 85 kts at
24/1200 UTC. By this time the typhoon was closing in on land, and
24/0600 UTC microwave imagery revealed that convection was decreasing
in the northwestern quadrant as a result of interaction with the Chinese
terrain. However, a well-defined eye was still evident and this clipped
the far northeastern coastline of Hainan at 24/1800 UTC.
At 0000 UTC on 25 August Krovanh was crossing the Leizhou Peninsula
of China with a slightly weakened maximum intensity of 80 kts. The
banding eye feature remained, although the central core temperature had
cooled significantly with the deep convection north of the circulation
(overland) continuing to wane. At 25/0600 UTC Krovanh was making a last
stand as it crossed the Gulf of Tonkin on its way to Vietnam. The MSW
reached 90 kts for the second time in the typhoon's history during this
period. After transiting the Gulf of Tonkin, Krovanh made landfall at
approximately 25/1500 UTC just north of Cam Pha, Vietnam. Upon reaching
the Vietnamese coast the typhoon weakened quickly with winds dropping
markedly to 65 kts. The system continued to weaken significantly as it
moved further into the continent. Both JTWC and JMA issued final
warnings at 26/0000 UTC, with JTWC's final position located 145 km north-
northwest of Hanoi, Vietnam. NMCC dropped Krovanh from their statements
at 26/0300 UTC as HKO as done six hours earlier.
C. Meteorological Observations
------------------------------
The following are a few rainfall totals I managed to obtain from
Luzon, Philippines. However, I was unable to track down the exact
date, time, and rainfall period.
Laoag 110 mm
Iba 203 mm
Dagupan 342 mm
Baguio 263 mm
Huang Chunliang has passed along a wealth of information on the
effects of Typhoon Krovanh and also some rain and wind observations
which follow.
(1) Landfalls
-------------
According to the NMC warnings, Typhoon Krovanh made landfall near
Wengtian Town, Wenchang City, Hainan Province around 24/2010 UTC with
a MSW of 74 kts and a minimum SLP of 965 hPa.
According to the NMC warnings, Typhoon Krovanh made landfall near
Qianshan Town, Xuwen County, Guangdong Province around 24/2215 UTC with
a MSW of 68 kts and a minimum SLP of 965 hPa.
(2) Rainfall Measurements
-------------------------
Province/ Station Period Rainfall
Region (UTC) (mm)
----------------------------------------------------------------
Hainan Dongfang 24/0000 - 25/0000 124.7
Hainan Dongfang 24/0000 - 26/0000 197
Hainan Baisha 24/0000 - 25/0000 199
Hainan Baisha 24/0000 - 25/1800 322
Hainan Wenchang 24/0000 - 25/0000 189
Hainan Changjiang 24/0000 - 25/0000 175
Hainan Changjiang 24/0000 - 26/0000 314.7
Hainan Nanfeng 24/0000 - 25/1800 394
Hainan Baoqiao 24/0000 - 25/1800 305
Hainan Jinjiang 24/0000 - 25/1800 392
Hainan Lin'gao 24/0000 - 26/0000 309.7
Hainan Danzhou 24/0000 - 26/0000 246.1
Guangxi Beihai 24/1200 - 25/1200 159.6
Guangxi Beihai 25/0000 - 26/0000 215.7
Guangxi Qinzhou 25/0000 - 26/0000 271
Guangxi Qinzhou 25/0000 - 27/0000 299.4
Guangxi Hepu 24/1200 - 25/1200 118
Guangxi Fangchenggang 24/1200 - 25/1200 108
Yunnan Jiangcheng 26/0000 - 27/0000 222
(3) Wind Observations
---------------------
(a) Guangdong Province
----------------------
(1) Gust reports: Zhanjiang Harbor (87 kts); Shangchuan Dao (78 kts);
the urban area of Zhanjiang City (72 kts); Haian Town, Xuwen
County (68 kts); Baoxi Salt Field (66 kts); Jizhao Town, Wuchuan
City (68 kts); Leizhou City (72 kts).
(2) Danzao, Nanhai District, Foshan City, reported a peak sustained
wind of 26 kts with a peak gust to 43 kts before the evening of
24 August (locally).
(b) Guangxi Zhuang Autonomous Region
------------------------------------
(1) Weizhou Dao reported a peak gust of 103 kts around 25/0900 UTC.
This peak turned out to be the maximum value ever recorded in the
Guangxi Region since 1982. (The eye of Typhoon Krovanh was
observed in Weizhou Dao around 25/0540 UTC, when the storm's
centre was located 18 km south of the island in the Gulf of
Tonkin.)
(2) Fangchenggang reported a peak gust of 72 kts on 25 August
(locally).
D. Damage and Casualties
------------------------
(1) Philippines
News reports indicate that Typhoon Krovanh caused serious damage
when it crossed the island of Luzon, but these were unspecific.
According to HKO's report on Krovanh, heavy rains were responsible for
the death of a girl and 1000 families were displaced. (See link to
HKO report below.)
(2) Guangdong Province, China
-----------------------------
At least two people have been confirmed dead from the typhoon in
Guangdong. Direct economic losses in western Guangdong are estimated
at 1.2 billion yuan.
(3) Hainan Province, China
--------------------------
The typhoon toppled 1700 houses and devastated 16 small reservoirs
in Hainan, affecting the lives and livelihoods of more than 1,884,000
residents in 129 towns of 11 cities/counties. However, no casualties
were reported in the province. Direct economic losses there are
estimated at 683 million yuan. In addition, all shipping services were
suspended for two days in south China's Qiongzhou Straits between the
island of Hainan and the mainland.
(4) Guangxi Zhuang Autonomous Region, China
-------------------------------------------
Beihai City was most seriously affected in Guangxi. About 50% of
the city's area suffered from a lack of power after 25/0700 UTC, and
the water supply for the whole city had been cut off by 25/0900 UTC.
Direct economic losses in the city were estimated at 988 million yuan.
No casualties were reported in Guangxi Region.
(5) Vietnam
-----------
One death and five injuries were attributed to Krovanh in Vietnam
where the typhoon destroyed 1000 homes, leaving several thousand people
homeless.
E. Additional Information
-------------------------
Additional information on Typhoon Krovanh can be found in the
report prepared by the HKO:
<http://www.weather.gov.hk/informtc/krovanh/krovanh.htm>
(Report written by Kevin Boyle and Huang Chunliang)
TROPICAL DEPRESSION LAKAY
18 - 21 August
---------------------------------------------
A monsoon trough became rather active after the middle of August
from the northern South China Sea eastward into the Pacific with the
axis lying approximately around 20N. Several circulations formed
along the trough and were treated in various ways by the several
TCWCs. On 18 August PAGASA named one of these disturbances Tropical
Depression Lakay (a Filipino term for "husband" or "male"). (This
was the disturbance with the temporary number 98W on NRL's website.)
JTWC never issued any warnings on the system, but JMA classified it
as a weak tropical depression in their bulletins. However, on the
19th both JTWC and JMA relocated 98W well to the east of their
previous positions. This disturbance subsequently became Tropical
Storm Vamco (TC-13W per JTWC's numbering system).
PAGASA, however, "transferred" Lakay to another disturbance to
the west, one that was listed on NRL's website as 99W. JTWC issued
a TCFA for this disturbance, and JMA monitored the system as a 30-kt
tropical depression in their bulletins on the 19th and 20th. JTWC
began mentioning yet another disturbance (91W) still further west
in the South China Sea at 20/0000 UTC and assigned a fair potential
for development. It appears that by the end of Tropical Depression
Lakay's life, the 91W center was the one being monitored by PAGASA.
JTWC issued a TCFA for this third disturbance also, but it was
cancelled at 21/0030 UTC as the system had moved inland into China.
The earlier TCFA for system 99W was cancelled also, at 20/1530 UTC.
JMA dissipated their tropical depression (which may have been either
99W or 91W) at 21/0000 UTC.
The Chinese warning agencies (NMCC, GRMC and CWBT), like JMA,
mentioned only one South China Sea circulation in their respective
bulletins and classified it as a tropical depression. Some of their
locations seem to be associated with 99W and some with 91W; others
were not near where JTWC was locating either of those two systems.
The HKO also tracked only one circulation, but didn't even accord
depression status to it, classifying it as only a low-pressure area.
PAGASA, on the other hand, elevated Lakay to tropical storm status
with 35-kt winds (10-min avg) for a period of 24 hours on 19 and 20
August.
If all this sounds confusing--don't worry, it truly is--and probably
was even more so to the harried forecasters who were trying to make
sense out of the monsoon "mess" as well as keep tabs on two other named
tropical cyclones (Krovanh and Vamco).
Huang Chunliang sent me a detailed analysis of the systems in
question, and the above discussion is based on the material he sent.
A special thanks to Chunliang for taking the time to attempt to untangle
the confusing scenario in the South China Sea during those days in
August and for sending the information to me. The disturbance which
moved inland brought some enhanced rainfall to southern China, and
Chunliang included some of the more notable amounts in his report,
which are tabulated below:
Station/ Province/ Period Rainfall
Number Region (UTC) (mm)
-----------------------------------------------------------------------
Xiamen (WMO 59134) Fujian 20/0000 - 21/0000 82.4
Xiamen (WMO 59134) Fujian 21/0000 - 22/0000 34.4
Hong Kong (WMO 45007) Hong Kong 20/0000 - 21/0000 75.0
Hong Kong (WMO 45007) Hong Kong 21/0000 - 22/0000 51.4
Shanwei (WMO 59501) Hong Kong 21/0000 - 22/0000 50.2
Also included was some information from Foshan City in Guangdong
Province. The tropical depression triggered a thunderstorm which
required some weather alerts. According to the final alert, the
automatic weather stations located in the districts of Sanshui, Nanhai
and Shunde reported gusts of Beaufort Force 8 to 9 during the storm.
Rainfall amounts of 30.4 mm, 42.7 mm and 38.8 mm were recorded in the
districts of Chancheng, Nanhai and Shunde, respectively, during a
one-hour period.
(Report written by Gary Padgett, based primarily on information sent
by Huang Chunliang)
TROPICAL STORM VAMCO
(TC-13W / TS 0311 / MANANG)
19 - 20 August
-----------------------------------------------
Vamco: contributed by Vietnam, is the name of a river in the western
part of southern Vietnam which originates in Cambodia
Manang: PAGASA name, is a Filipino female nickname, used primarily
for an older, unmarried woman
A. Storm History
----------------
Short-lived Tropical Storm Vamco began as an area of convection
located roughly 400 nm east of Luzon, Philippines. The STWO issued at
0600 UTC on 18 August relocated the area to a position near 20.0N,
122.3E, or approximately 120 nm south-southeast of Taiwan. Animated
enhanced satellite imagery depicted disorganised convection on the
southern side of a LLCC. Upper-air analysis showed weak shearing
conditions over the area and the development potential on this state-
ment was upgraded to fair. This was further upgraded to good at 19/0000
UTC based on improved organisation during the previous six hours. This
STWO was issued in anticipation of a tropical depression, and the first
warning on Tropical Depression 13W was released at 19/0300 UTC. (JMA,
NMCC and CWBT issued their first bulletins at 19/0000 UTC.)
At 0000 UTC on 19 August Tropical Depression 13W was located approxi-
mately 270 nm east-southeast of Taiwan, tracking toward the north-
northwest at a leisurely 5 kts. Even though the system was rapidly
organising, the Prognostic Reasoning message indicated only marginal
strengthening due to the presence of less-than-ideal upper-level
conditions, interaction with land, and possible interference from the
remnants of Tropical Depression 12W. By 0600 UTC the forward speed had
more than trebled with the storm temporarily moving on a northward path.
At this time JMA and NMCC upgraded the depression to tropical storm
intensity with JMA assigning the name Vamco. (PAGASA issued the first
of three warnings at this time on Manang (their internal name), and
after the storm had skirted through that agency's AOR, the third and
final warning was issued at 19/1800 UTC. HKO also began issuing
warnings on Vamco at 19/0600 UTC but never classified the system as a
tropical storm.)
Movement for the rest of Vamco's life was toward the northwest, and at
19/1800 UTC was centred only 30 nm northeast of Taipei, Taiwan. (JTWC
upgraded Vamco to tropical storm status at this time.) However, recent
microwave imagery indicated that the LLCC was partially-exposed to the
east of the deep convection. After its close flirt with Taiwan, the
centre made landfall near Fanshan, China, at approximately 0030 UTC on
20 August and was downgraded to a 25-kt tropical depression at 20/0600
UTC. Vamco was dissipating as a significant tropical cyclone over land
by 20/1200 UTC, the time of the final JTWC warning. (All agencies, bar
CWBT, had discontinued warnings by this time: JMA at 20/0300 UTC, HKO
at 20/0600 UTC, and NMCC at 20/0900 UTC. CWBT issued their last state-
ment at 20/1800 UTC.)
B. Meteorological Observations
------------------------------
Huang Chunliang has sent some rainfall observations and wind reports.
(Thanks to Chunliang for sending this information.)
1. Landfall
-----------
According to the NMCC warnings, Tropical Storm Vamco made landfall
near Aojiang Town, Pingyang County, Wenzhou City, Zhejiang Province,
around 20/0210 UTC with a MSW (10-min avg) of 45 kts and a minimum SLP
of 990 hPa.
2. Rainfall Data
----------------
Provinces/ Stations Periods Rainfall
Regions UTC mm
-----------------------------------------------------------------------
Zhejiang Pingyang, Wenzhou City 19/0000 - 20/0000 70
Zhejiang Pingyang, Wenzhou City 19/0600 - 20/0600 101
Fujian Fuding, Ningde City 19/0000 - 20/0000 52
Taiwan Jhuangwei, Ilan County 18/1600 - 19/2100 69
Taiwan Luodong, Ilan County 18/1600 - 19/2100 61
Taiwan Suao, Ilan County 18/1600 - 19/2100 50
Taiwan Tatunshan, Taipei City 18/1600 - 19/2100 50
Taiwan Rueifang, Taipei County 18/1600 - 19/2100 51
3. Gust Observations from Zhejiang Province
-------------------------------------------
Station Peak Gust
--------- ---------
Pingyang 49 kts
Nanji Dao 54 kts
D. Casualties and Damage
------------------------
Preliminary statistics indicated that some 326,000 residents of
Pingyan County, Zhejiang Province, were affected by the storm, though no
casualties were reported. A total of 984 houses collapsed and 4896 were
partially damaged in the county. Moreover, 1286.67 hectares of paddy-
fields were ruined with 653.33 hectares of economic crops being damaged.
Direct economic losses there were estimated at 38.56 million yuan.
Like the earlier Severe Tropical Storm Morakot, Tropical Storm Vamco
turned out to be more of a beneficial tropical cyclone than a baleful
one, too. Thanks to the storm, the drought in southern Zhejiang and
northern Fujian was eased once again.
No other reports of damages associated with Tropical Storm Vamco
were received.
(Report written by Kevin Boyle and Huang Chunliang)
TYPHOON DUJUAN
(TC-14W / TY 0313 / ONYOK)
28 August - 3 September
----------------------------------------------
Dujuan: contributed by China, is the name for the flowering plant
'azalea'; the word also means 'cuckoo' in Chinese
Manang: PAGASA name, is a Filipino male name which also means 'midget'
A. Storm Origins
----------------
Typhoon Dujuan originated from an area of deep convection that was
noted in GOES-9 infrared satellite images as early as 25 August. (All
the STWOs that included the pre-Dujuan disturbance were unavailable
to the authors.) The slow-moving suspect area could be tracked for
several days moving westward with variable convective amounts, and in
fact by the end of the 25th there was very little associated convection.
This theme continued into the 26th, but increasing organisation was
evident by late on the 27th. JTWC issued a TCFA on 27 August, locating
the system near 18.4N, 138.1E. The first warning was issued at 28/0600
UTC, followed by an upgrade to tropical storm status on the second
warning six hours later. (The tropical cyclone remained unnamed until
JMA upgraded it to tropical storm intensity at 29/1800 UTC.) Tropical
Storm 14W continued to organise while moving southwestward to west-
southwestward, and at 29/0000 UTC was located approximately 750 nm east
of the Philippines (near 16.1N, 135.3E.) Animated multi-spectral imagery
revealed enhanced equatorward outflow and satellite CI estimates were
30 and 35 kts.
B. Storm History
----------------
Animated multi-spectral satellite imagery at 29/0600 UTC showed that
the northern portions of Tropical Storm 14W were being sheared as a
result of a nearby TUTT cell located just north of the system. Feeling
the benefit of equatorial outflow, a second channel was opening as the
upper-level LOW moved in tandem with the cyclone. At 29/1200 UTC the
warning intensity was raised to 45 kts, in line with satellite CI
estimates, and PAGASA named the system Onyok as the storm entered their
AOR. The internationally recognized name Dujuan came into force when JMA
upped their 10-min avg MSW to 35 kts at 29/1800 UTC. The warning issued
by JTWC at this time indicated that Dujuan was on the verge of becoming
a typhoon with the MSW estimated at 60 kts and water vapour imagery
indicating increased outflow in all quadrants.
At 0000 UTC on 30 August the MSW reached 65 kts based on a compromise
of satellite intensity estimates ranging from 55 to 77 kts. At this
time Typhoon Dujuan was located approximately 690 nm east of the
Philippines, moving on a slow westerly heading of 3 kts. Animated multi-
spectral and microwave imagery showed a tightly-curved band forming near
the centre of the system. As Dujuan turned northwestward and
accelerated, the MSW was increased further to 75 kts, and a tightly-
curved banding eye feature was noted at 30/1200 UTC in microwave imagery.
After briefly turning poleward, Dujuan reverted back to its westerly to
west-northwesterly heading the next day. (JMA upgraded Dujuan to typhoon
status at 30/1800 UTC, and NMCC and PAGASA did so six hours later.)
By 31/0000 UTC 31 Typhoon Dujuan/Onyok was positioned approximately
595 nm east-southeast of Taiwan with a MSW of 80 kts. This intensity
was upped further to 90 kts at 0600 UTC, and raised to 100 kts twelve
hours later. A 31/1214 UTC 85 GHz microwave image showed the presence
of tightly-wrapped banding features but no indications of an eye.
However, in contrast, a symmetrical eye was analysed on the 37 GHz
channel. Continuing on a west-northwesterly path, Dujuan had moved to
within 260 nm east-southeast of Taiwan by 0000 UTC 1 September. The MSW
had risen to 120 kts, equivalent to a Category 4 hurricane, at this time
with an upper-level LOW east of Dujuan aiding outflow. A 31/2235 UTC
SSM/I pass depicted concentric eyewalls. By 01/1200 UTC the southern
part of Taiwan lay within the radius of 50 kt winds as the eye of Dujuan
was centred approximately 65 nm southeast of the southern tip of the
island. At this time the intensity was peaking at 125 kts, but fell
back slightly to 120 kts at 1800 UTC. The symmetrical concentric eyes,
noted in an earlier SSM/I pass, had disappeared, although an eye feature
was evident in a 01/2232 UTC TRMM image. (The peak 10-min avg MSW
estimated by JMA was 80 kts. Among the Asian TCWCs, the highest 10-min
avg MSW of 100 kts was assigned by HKO.)
Even though Typhoon Dujuan was past its prime and was now on a
definite weakening trend, the storm's glory days were not over. By 0000
UTC on 2 September, Dujuan was beginning its approach to Hong Kong,
China, with the maximum intensity still at 120 kts. At this time, the
central core of Dujuan lay approximately 220 nm east of Hong Kong,
closing to 150 nm by 0600 UTC. Another six-hour increment saw Dujuan
making landfall on the Chinese coast with a maximum intensity of 100 kts.
(The exact time of landfall as indicated in JTWC's 02/1800 UTC warning--
#22--was at 1400 UTC.) Now moving westward across the Chinese mainland,
the typhoon weakened quickly and by 1800 UTC the MSW was barely at
typhoon strength. The last warning issued by JTWC at 03/0000 UTC
located the dying storm near Yulin, China (22.6N, 110.5E). Dujuan was
downgraded to a 40-kt tropical storm on this last statement, based on
synoptic reports and CI estimates of 65 kts. NMCC downgraded Dujuan to
30 kts at 03/0000 UTC, and issued their final warning three hours later.
C. Meteorological Observations
------------------------------
(1) Landfall (based on the NMC warnings)
----------------------------------------
Typhoon Dujuan made its first landfall near Gangkou Town, Huidong
County, Guangdong Province, around 02/1150 UTC with a MSW of 78 kts,
gusting to 107 kts, with a CP of 960 hPa. Crossing the Gulf of Daya,
the storm made a second landfall near the coastal area of eastern
Shenzhen City, Guangdong Province, around 02/1250 UTC. Dujuan entered
the waters of the mouth of Zhujiang River after rampaging across
Shenzhen. Then, the third and final landfall occured near Nanlang Town,
Zhongshan City, Guangdong Province, around 02/1515 UTC with a MSW of
64 kts, gusting to 78 kts and with a CP of 975 hPa.
(2) Rainfall Measurements
-------------------------
Station Province/ Period Rainfall
Region (UTC) (mm)
-----------------------------------------------------------------
Hengchun (WMO 46759/59559) Taiwan 31/1600 - 01/1600 106.0
Hengchun (WMO 46759/59559) Taiwan 01/1600 - 02/1600 108.0
Chengkung (WMO 46761) Taiwan 01/1600 - 02/1600 152.5
Lanyu (WMO 46762/59567) Taiwan 01/1600 - 02/1600 133.0
Taichung (WMO 46766/59562) Taiwan 01/1600 - 02/1600 146.0
Tu-chang, Ilan County Taiwan 31/1600 - 01/1500 197
Tan-ta, Nantou County Taiwan 31/1600 - 02/0000 205
Hsi-ceiu, Hsinchu County Taiwan 31/1600 - 02/0900 229
Liyutan, Hualien County Taiwan 31/1600 - 02/0900 511
Yuli, Hualien County Taiwan 31/1600 - 01/2100 304
Fangshan, Pingtung County Taiwan 31/1600 - 01/2100 271
Chih Pen, Taitung County Taiwan 31/1600 - 01/2100 153
Guangfu, Hualien County Taiwan 31/1600 - 02/0000 350
Shihding, Taipei County Taiwan 31/1600 - 02/0000 114
Maubitou, Pingtung County Taiwan 31/1600 - 02/0900 628
Taipingsha, Ilan County Taiwan 31/1600 - 02/0900 385
Luye, Taitung County Taiwan 31/1600 - 02/0900 341
Ao-wan-ta, Nantou County Taiwan 31/1600 - 02/0900 261
Kaokou, Chia-I County Taiwan 31/1600 - 02/0900 191
Mu Cha, Taipei County Taiwan 31/1600 - 02/0900 152
Nansha, Guangzhou City Guangdong 02/0000 - 03/0300 145.9
Puning City Guangdong 02/0000 - 03/0000 131
Puning City Guangdong 02/0000 - 04/0000 183.0
Lishui, Nanhai District, Guangdong 02/0000 - 03/0200 100.9
Foshan City
(3) Hourly Sustained Wind and Pressure Observations
---------------------------------------------------
NOTE: All MSW values are 10-min avg winds.
(a) Station: Lanyu, Taiwan (WMO 46762/59567),
Lat. 22.0N, Lon. 121.6E, Alt. 325 m
Winds reached sustained gale force at 01/0100 UTC, then
dropped below gale force during the next two hourly observations.
At 01/0400 UTC winds had risen above gale force and so remained
through the 1700 UTC observation. Winds were 60 and 62 kts at
0500 and 0600 UTC, respectively, and the peak hourly MSW of 89 kts
occurred at 1400 UTC. The 1500 UTC MSW was 84 kts, and the minimum
hourly pressure of 926.6 hPa occurred at 1300 UTC.
(b) Station: Dongshi, Taiwan (WMO 46730)
Lat. 23.3N, Lon. 119.7E, Alt. 45 m
The maximum hourly MSW of 41 kts occurred on 2 September
from 0100 through 0400 UTC. The minimum pressure hourly reading
of 982.4 hPa was taken at 1700 UTC on 1 September.
(c) Station: Hengchun, Taiwan (WMO 46759/59559)
Lat. 22.0N, Lon. 120.8E, Alt. 24 m
The maximum hourly MSW of 41 kts occurred at 1700 UTC on
1 September while the minimum hourly pressure of 963.6 hPa was
measured at 01/1600 UTC.
(4) Peak Sustained Wind and Gust Observations from Taiwan
---------------------------------------------------------
NOTE: All MSW values are 10-min avg winds.
Only those stations that reported peak gusts of typhoon force
are given (wind direction is in degrees/dates are local dates):
Peak Sust. Wind Peak Gust
Station (kts / dir / date) (kts / dir / date)
---------------------------------------------------------------
Lanyu 94.9/ 40 / 1st 146.2/ 20 / 1st
Dawu 30.7/ 110 / 2nd 71.1/ 100 / 1st
An Bu 28.6/ 180 / 2nd 65.1/ 200 / 2nd
Keelung 22.4/ 100 / 2nd 64.9/ 200 / 2nd
Hengchun 45.3/ 110 / 2nd 92.7/ 160 / 2nd
Sun Moon Lake 22.6/ 120 / 2nd 66.5/ 120 / 2nd
Dongshi 47.2/ 150 / 2nd 65.7/ 150 / 2nd
Note 1: Stations Taitung, Taipei, Hsinchu, Penghu, Kaohsiung, Chengkung,
Ilan and Suao all reported peak gusts of Beaufort Force 10.
Note 2: Yu Shan, a weather station located in the mountainous region of
Nantou County, reported a peak gust of 99.3 kts at 01/1911 UTC.
Note 3: It should be noted that the anemometer in Lanyu was destroyed
around 01/1300 UTC--the third time since the weather station was built
56 years ago.
(5) Wind Observations from Fujian Province
------------------------------------------
Station Peak Gust
------------------------------------------
The urban area of Fuzhou City 52 kts
Licheng, Quanzhou City 51 kts
Yongchun, Quanzhou City 52 kts
Chongwu, Quanzhou City 51 kts
Jiuxianshan, Quanzhou City 78 kts
Dongshan, Zhangzhou City 64 kts
Note: Gusts of Beaufort Force 7 or higher were recorded in 30 cities/
counties of the province during the period from 01/0600 though 02/1200
UTC.
(6) Wind Observations from Guangdong Province
---------------------------------------------
Station Peak Gust
----------------------------------------------
Nansha Power Factory, Guangzhou City 91 kts
Nansha Headquarters, Guangzhou City 75 kts
Fangcun District, Guangzhou City 42 kts
Nanshan District, Shenzhen City 97 kts
Note: Jiujiang, Nanhai District, Foshan City, reported a peak 10-min
avg sustained wind of 37.9 kts at 02/1622 UTC with a peak gust of 59.6
kts at 02/1612 UTC.
D. Damage and Casualties
-------------------------
(1) Taiwan Region
-----------------
In southern Taiwan three people were killed, one was missing and
eight were injured during the approach of Dujuan. The electricity
supply to about 590,000 families was interrupted. All transportation
services in southern Taiwan were temporarily suspended. As of 04/0800
UTC the agricultural loss had reached NT$1.417 billion with another
NT$46.9 million losses in stockbreeding.
(2) Fujian Province
-------------------
Over 500 trees were uprooted or partly damaged in the urban area of
Fuzhou City. However, no casualties were reported in Fujian province.
(3) Guangdong Province
----------------------
About 6,410,000 residents in Guangdong Province were affected by the
typhoon. Highways, infrastructure for telecommunications, water and
power supplies, irrigation systems, and crops suffered serious damage
as Dujuan, the most powerful typhoon that has affected the Zhujiang
River Delta since 1979's Typhoon Hope, swept through. Some 54,000
houses collapsed, and 139,000 hectares of crops were damaged. Direct
economic losses in the province were estimated at 2.287 billion yuan.
Power supplies in 90% of the area in Shenzhen were interrupted as
the typhoon struck the city.
Dujuan also turned out to be the most deadly typhoon for China so
far this season. In Zhujiang River Delta, at least 46 people lost
their lives and about 1000 were injured in the storm.
(4) Hong Kong Special Administrative Region
-------------------------------------------
In Hong Kong Dujuan disrupted public transport systems, closed
the Hong Kong stock exchange, and caused the cancellation of 221
flights while delaying 139 others. More than 2000 people were
stranded. Injuries in association with Dujuan were slight (only
22 reported), but four fishermen were missing after the storm's
passage and feared drowned after a rescue search failed to find
their boat.
See the report on Typhoon Dujuan prepared by the HKO at the
following link:
<http://www.weather.gov.hk/informtc/dujuan/dujuan.htm>
(5) Macao Special Administrative Region
---------------------------------------
The Macao Meteorological and Geophysical Bureau (SMG), the local
meteorological service, raised storm signal No. Eight, the third-highest
storm warning signal as the typhoon approached the south China coast
Tuesday evening. The public traffic was suspended at 9:00 pm on Tuesday.
Over 30 flights through the Macao Airport were delayed, and two bridges
linking the Macao Peninsula with Taipa Island were closed as the
No. Eight warning was raised. However, no big losses were reported.
E. Double-eyed 'Cuckoo'
-----------------------
Both the Taiwan and Hong Kong radars captured the 'cuckoo' with
double (concentric) eyes. A HKO report on this interesting phenomenon
can be found at the following link:
<http://www.weather.gov.hk/informtc/tcimage/double_eye.htm>
Some CWB radar imageries described a possible anticlockwise movement
of the inner eye, with the outer one being the frame of reference,
while the typhoon was heading for the southern tip of Taiwan Island.
(Report written by Kevin Boyle and Huang Chunliang)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for August: 1 tropical depression **
** - classified as a tropical depression by IMD only
North Indian Ocean Tropical Activity for August
-----------------------------------------------
I received some information from Huang Chunliang regarding a system
in the Bay of Bengal which was classified as a depression by the Indian
Meteorological Department (IMD). This system was mentioned on 27 August
as a low-pressure area over the northwestern Bay of Bengal off the
Orissa-West Bengal coast. During the evening it strengthened into a
depression and moved in a westerly direction, crossing the Orissa coast
early on the 28th. The system continued moving farther inland and had
weakened into a low-pressure area by the 29th. The bulletins from the
IMD indicate that the axis of the monsoon trough at sea level passed
through the center of the depression, so the system is probably best
classified as a monsoon depression. No warnings were issued on this
system by JTWC; in fact, it was never mentioned in that agency's STWOs
for the North Indian Ocean. The depression did enhance monsoonal rain-
fall in portions of eastern India. (A special thanks to Chunliang for
sending me the relevant IMD bulletins.)
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for August: No tropical cyclones
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for August: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
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
from the archive sites listed below. (Note: I do have a limited e-mail
distribution list for the track files. If anyone wishes to receive
these via e-mail, please send me a message.)
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. Back issues can be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Michael Pitt, and
Chris Landsea):
<http://australiasevereweather.com/cyclones/>
<http://www.typhoon2000.ph> OR <http://64.235.42.210>
<http://mpittweather.com>
<ftp://ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/>
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:
<http://www.met-office.gov.uk/sec2/sec2cyclone/sec2cyclone.html>
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the complete Annual Tropical
Cyclone Report (ATCR) for 2002 (2001-2002 season for the Southern
Hemisphere). ATCRs for earlier years are available also.