[Index]
Monthly Global Tropical Cyclone Summary June 2003
[Summaries and Track Data] [Prepared by Gary Padgett]
| Tropical
Cyclones
[Index] |
Monthly Global Tropical Cyclone Summary June 2003 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
JUNE, 2003
(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.)
*************************************************************************
JUNE HIGHLIGHTS
--> Rare Atlantic depression forms east of Lesser Antilles
--> Two out-of-season South Pacific tropical cyclones--one a hurricane
--> Typhoon affects Philippines and Japan
--> Tropical storms strike Mexico and Louisiana
*************************************************************************
***** Feature of the Month for June *****
NORTH INDIAN OCEAN TROPICAL CYCLONE STATISTICS
----------------------------------------------
For the past couple of years I have included some Dr. Gray-style
Net Tropical Cyclone activity (NTC) statistics for the Atlantic and
Northeast Pacific basins. It has been my wish to begin to produce
similar tables for the other tropical cyclone basins, but I have not
had the time to pursue this heretofore. A few years back I'd written
some software to read through the Atlantic and Northeast Pacific Best
Track files and calculate the required parameters, but I did not until
recently have data for the other basins in a similar format. A few
months ago I received from Charles Neumann a set of Best Track (BT) files
for the North Indian Ocean and the Southern Hemisphere in essentially
the same format--similar enough that with a little modification my
earlier software would read the files and extract the needed parameters.
So this month I'm featuring some tables of tropical cyclone statistics
for the North Indian Ocean basin--the basin which has the lowest annual
number of tropical cyclones, but which has seen tragically high numbers
of lives lost due to intense storms sweeping across the coasts of India,
Pakistan and Bangladesh. For the present I have included only the
period 1981 through 2002. Mr. Neumann indicated that the file, which
begins with 1965, is based largely upon JTWC's database. I initially
intended to begin with 1975, which was the first year that JTWC issued
warnings operationally for essentially the entire basin. However, I
discovered some discrepancies between the BT files and the Annual
Tropical Cyclone Reports (ATCR) prepared by JTWC up through and including
1980. Since the two sources began to agree almost exactly in 1981, I
chose that year as my starting point.
JTWC began issuing tropical cyclone warnings for the eastern Bay of
Bengal east of 90E in 1971. The area of coverage was extended west to
80E in 1974, covering the entire Bay of Bengal. In 1975 the western
limit was extended again to 62E, taking in the eastern half of the
Arabian Sea. Finally, in 1976 the AOR was extended westward to the
African coast. For purposes of this discussion I have used the
following definitions:
NS - a tropical cyclone with 1-min avg MSW >= 34 kts
H - a tropical cyclone with 1-min avg MSW >= 64 kts
IH - a tropical cyclone with 1-min avg MSW >= 96 kts
NSD - four 6-hour periods in which a NS is operating
HD - four 6-hour periods in which a H is operating
IHD - four 6-hour periods in which an IH is operating
NTC - (((Total NS/Avg NS) + (Total H/Avg H) + (Total IH/Avg IH) +
(Total NSD/Avg NSD) + (Total HD/Avg HD) +
(Total IHD/Avg IHD))/6) x 100%
In 1975 the BT file lists 7 NS with 4 H. The ATCR lists 6 NS with
3 H. However, one of the NS (a January system) is carried as only a
depression in the BT file. For 1976 the differences are even greater.
The BT file lists 10 NS with 7 H, but the ATCR lists only 5 NS with
no hurricanes. As late as 1980, the BT file contains 4 NS, but the ATCR
mentions only two, and both of those with a MSW of only 35 kts. However,
beginning with 1981, there is perfect agreement regarding the number of
storms, and the peak MSW values are usually the same, occasionally
differing by perhaps 5 kts. This agreement between the two sources
suggests that the BT file can be considered fairly reliable from that
point on. I seem to recall an e-mail from Mr. Neumann several months
ago when he sent the North Indian Ocean file in which he stated that he
didn't have a whole lot of confidence in the intensities until the early
1980s.
In compiling the statistics, I included all tropical cyclones which
occurred in the basin, whether they originated there or not. During
the period under consideration, I am aware of four systems of Northwest
Pacific basin origin which either moved into or redeveloped in the
Bay of Bengal: Gay of 1989, Forrest of 1992, Linda of 1997, and Vamei
of 2001. I do not have the BT file for 2002 yet--for that year the
numbers were taken from the operational tracks. I did not include
certain non-operational systems in recent years which I had included in
the monthly track files I prepare, based upon information from individual
meteorologists who performed analyses of them at my request. Nor did
I include a system in October, 2001, which was treated as a "cyclonic
storm" by IMD but for which no warnings were issued by JTWC. One
knowledgeable meteorologist stated to me that the system was almost
certainly not a tropical storm.
The tables follow. The information contained in each should be
self-explanatory. Following the tabulated data are some comments.
Annual Tropical Cyclone Activity
--------------------------------
Year NS H IH NSD HD IHD NTC
1981 3 2 0 13.50 2.50 0.00 61
1982 5 2 1 15.00 3.75 1.00 119
1983 3 0 0 5.25 0.00 0.00 16
1984 4 2 0 17.00 4.25 0.00 78
1985 6 0 0 13.50 0.00 0.00 36
1986 3 0 0 4.75 0.00 0.00 16
1987 8 0 0 19.50 0.00 0.00 50
1988 5 1 1 12.25 4.00 0.75 102
1989 3 1 1 9.50 4.75 2.00 119
1990 2 1 1 9.00 3.25 2.00 106
1991 4 1 1 11.00 3.50 1.75 112
1992 11 3 1 36.50 4.00 2.00 194
1993 2 2 0 6.50 2.50 0.00 49
1994 5 1 1 12.00 2.25 1.00 96
1995 4 2 1 11.00 2.50 0.75 99
1996 8 4 1 32.25 3.75 1.00 170
1997 5 3 1 18.75 4.75 1.25 144
1998 8 5 1 19.50 6.50 0.50 172
1999 5 3 3 17.50 9.25 5.25 288
2000 4 1 0 10.00 1.25 0.00 43
2001 4 1 1 9.00 3.75 1.00 98
2002 5 0 0 12.75 0.00 0.00 32
Total 107 35 15 316.00 66.50 20.25
Avg. 4.86 1.59 0.68 14.36 3.02 0.92
Monthly Tropical Storm Activity
-------------------------------
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1981 1 1 1
1982 2 2 1
1983 1 1 1
1984 1 1 2
1985 2 2 1 1
1986 1 2
1987 1 2 2 1 2
1988 1 1 2 1
1989 1 1 1
1990 1 1
1991 1 1 1 1
1992 1 2 1 2 4 1
1993 1 1
1994 1 1 1 1 1
1995 1 1 2
1996 1 3 2 2
1997 1 1 3
1998 2 1 1 1 2 1
1999 1 1 1 2
2000 2 1 1
2001 1 1 1 1
2002 2 2 1
-----------------------------------------------------------------
Total 2 2 1 2 16 13 1 1 4 22 32 11
Avg. .09 .09 .05 .09 .73 .59 .05 .05 .18 1.00 1.45 .50
Monthly Hurricane Activity
--------------------------
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1981 1 1
1982 1 1
1983
1984 2
1985
1986
1987
1988 1
1989 1
1990 1
1991 1
1992 1 2
1993 1 1
1994 1
1995 2
1996 1 1 1 1
1997 1 1 1
1998 1 1 2 1
1999 1 2
2000 1
2001 1
2002
-----------------------------------------------------------------
Total 0 0 0 2 7 2 0 0 1 3 16 4
Avg. .00 .00 .00 .09 .32 .09 .00 .00 .05 .14 .73 .18
The latter two tables reveal what all those who study tropical
cyclones on a global scale know--that the North Indian Ocean has in
essence two tropical cyclone "seasons" each year. These occur during
the spring and autumn transition seasons when the ITCZ is moving
northward and southward, respectively, across the basin. The very
low incidence of wintertime tropical cyclones is to be expected, but
the almost complete absence during the midsummer months of July and
August is most unusual compared with other tropical cyclone basins.
The reason is that during the boreal summer the ITCZ migrates far
enough north that by and large it lies over land. The very few storms
which have formed in the latter part of June and in July and August
usually developed at higher latitudes (around 20-23N) in the upper
reaches of the Arabian Sea and Bay of Bengal.
The periods April-June and October-December account for 90% of the
tropical storm and 97% of the hurricane activity, respectively. The
only known storm of hurricane intensity during the period under
consideration which formed outside the six months referenced above was
a hurricane in September, 1997. November is the most active month for
tropical storms (31), followed by October (22) and May (16). November
also has the highest number of storms of hurricane intensity (16), but
May has seen more hurricanes (7) than October (3). In fact, only two
Octobers have seen hurricane activity since prior to 1981: 1996 and
1999. The month of October, 1999, stands out as one of the most
remarkable months in recent history in the North Indian Ocean. Two
very intense tropical cyclones formed in the Bay of Bengal and both
struck India's eastern coastal regions with winds estimated at 120 kts
and 140 kts, respectively. The second of these, TC-05B, was responsible
for over 10,000 fatalities.
With regard to the annual series chart (the first table), one feature
which immediately grabs the attention is the very low incidence of
intense tropical cyclones during the early and mid-1980s. From 1981
through 1987 only one IH developed, and there were three consecutive
seasons with no cyclones of hurricane intensity reported. Since 1988
only three seasons have failed to produce an IH: 1993, 2000 and 2002.
The 2002 season was the first since 1987 in which no hurricane-intensity
systems developed. Except for 1982, the NTC was well-below average
during the period 1981-1987. Activity began to increase in 1988,
reaching a very high NTC of 194 in 1992--the year with the highest
number of NS. The years 1996-1999 represent the multi-year period with
the highest annual NTC. The "granddaddy" of all years was 1999 with a
NTC of 288, due to the occurrence of three IH: the two October storms
mentioned above, and an intense May hurricane (TC-02A) which struck
northwestern India and Pakistan.
One final comment--as noted above I chose to include all activity
in the North Indian Ocean basin, both native storms and a few visitors
from the Northwest Pacific basin. There are also some reasonable
arguments for looking at a basin's annual activity in terms of only those
cyclones which originated there. The inclusion of Typhoon Linda's Bay
of Bengal excursion likely augmented the 1997 NTC by a fair amount, but
the weak redevelopment of former Typhoon Vamei in December, 2001, added
only a negligible boost to that year's NTC. However, it is a very
different story for 1989 and 1992. Although the North Indian Ocean
in 1992 produced a record 10 native NS, Tropical Storm Forrest from
the South China Sea moved across the Malay Peninsula and intensified
into a 125-kt cyclone in the Bay of Bengal, yielding two full IHD and
giving a significant boost to that year's NTC. The NTC of 119 obtained
for 1989 was even more dependent upon a visitor. A fairly strong
tropical storm had occurred in May, and a minimal tropical storm
developed in June, but that year saw no more activity until November,
when Typhoon Gay moved from the Gulf of Thailand across the Malay
Peninsula and intensified significantly in the Bay of Bengal. Gay
eventually struck the eastern coast of India as a very small cyclone
with winds estimated at 140 kts. Gay, Tropical Cyclone 02B of 1991, and
Tropical Cyclone 05B of 1999 reign as a triumvirate of the most intense
North Indian Ocean cyclones currently in the database, each reaching an
estimated peak MSW of 140 kts (per JTWC's analysis). TC-05B of 1999 was
deadly enough (as noted above), but TC-02B of 1991 was even deadlier--the
storm resulted in an estimated 138,000 deaths in Bangladesh.
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for June: 1 tropical depression
1 tropical storm
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 June
-----------------------------------
Two tropical cyclones developed in the Atlantic basin during the month
of June with one becoming a named storm. A strong tropical wave moved
off the west African coast on 7 June, moving westward. By the next day
a 1012-mb LOW was associated with the wave. A Tropical Weather Outlook
issued by TPC/NHC at 1530 UTC on the 9th indicated that there was some
potential for further development of the wave, which was then located
approximately 700 nm southwest of the Cape Verde Islands. By late on
the 10th convection had increased and a tropical depression appeared to
be forming. The first advisory on Tropical Depression 02 was issued at
0300 UTC on 11 June, placing the center approximately 1125 nm east-
southeast of Barbados. Satellite intensity estimates during the early
morning of 11 June suggested that the depression was near tropical storm
intensity, but due to center location uncertainties based on nighttime
infrared imagery, it was decided to wait for visible pictures before
upgrading the system.
The 1500 UTC advisory noted that while CI estimates remained at 35 kts
from two agencies, convection had diminished and a recent QuikScat pass
was inconclusive as to the intensity. The depression's signature began
to go downhill from that point, and the final advisory at 12/0300 UTC
downgraded the system to an open tropical wave roughly 750 nm east-
southeast of Barbados. TD-02 was only the third known tropical
depression to have formed east of the Lesser Antilles during June since
1967, the others being Tropical Storm Ana in 1979 and a strong tropical
depression in the eastern Atlantic in 2000. Had TD-02 managed to reach
tropical storm status, it likely would have died very young as the upper-
level environment downstream was very hostile for tropical cyclone
maintenance.
The other tropical cyclone was Tropical Storm Bill, which was upgraded
directly to a tropical storm on the first advisory at 1500 UTC on the
29th in the central Gulf of Mexico. Climatologically, a tropical storm
forms in the Atlantic basin around every other year, and Bill was right
on schedule, being the first June storm since the destructive Tropical
Storm Allison in 2001. A complete report on Tropical Storm Bill follows.
TROPICAL STORM BILL
(TC-03)
29 June - 4 July
---------------------------------------
A. Storm Origins
----------------
A Tropical Weather Outlook issued by TPC/NHC at 1530 UTC on 24 June
seems to be the first mention of the area of disturbed weather which
ultimately developed into Tropical Storm Bill. Cloudiness and thunder-
storms had increased over the western Caribbean between Honduras and
Jamaica in association with a westward-moving tropical wave which was
interacting with an upper-level LOW. The activity was forecast to move
slowly northwestward toward the Yucatan Peninsula. Little change in the
disturbance was noted on the 25th and 26th, and the Outlooks on 26 June
pointed out that upper-level conditions were unfavorable for tropical
cyclone formation, but were forecast to become more favorable over the
next few days.
By early on the 27th convection had increased over the northwestern
Caribbean Sea but there were no signs of any surface development. By
late afternoon satellite imagery and surface observations indicated a
broad area of low pressure over the Yucatan Peninsula accompanied by a
sizeable area of convection over the Caribbean. Surface pressures had
begun to fall, but significant development was being inhibited by the
system's location over land. Little change was noted on the 28th--by
late in the day disturbed weather extended from the Yucatan Peninsula
northward into the eastern Gulf of Mexico. Early on 29 June visible
satellite imagery revealed the development of a weak LLCC in the south-
central Gulf, and ship H3GQ reported winds to 38 kts under the deep
convection 150 nm northeast of the center around 1200 UTC. At 1300 UTC
TPC/NHC issued a Special Tropical Disturbance Statement announcing that
advisories would be initiated on the developing tropical storm at
1500 UTC.
B. Storm History
----------------
The first advisory on Tropical Storm Bill was issued at 1500 UTC,
placing the center approximately 400 nm south-southeast of Port Arthur,
Texas, and moving northwestward at 12 kts. A tropical storm watch was
issued for a portion of the Gulf of Mexico coastline extending from
San Luis Pass, Texas, to Morgan City, Louisiana. The initial intensity
was set at 35 kts--this was increased to 40 kts at 2100 UTC based on a
ship report of 40-kt winds 80 nm northeast of the center at 1500 UTC and
information obtained from a reconnaissance mission into the cyclone. The
plane found maximum flight-level winds of 53 kts in the eastern quadrant
at 2011 UTC with a central pressure of 1010 mb--somewhat high for a
tropical storm, but the pressure gradient to the east of Bill was quite
large.
At 0300 UTC on 30 June Tropical Storm Bill's center was located about
190 nm south of Morgan City, Louisiana, moving north at 12 kts. As
Bill's trajectory became more northerly, tropical storm warnings were
shifted eastward accordingly, reaching to Pascagoula, Mississippi. A
hurricane watch was also issued for portions of the coastline in the
event that Bill should strengthen to hurricane intensity before making
landfall. The center had moved northward closer to the deep convection,
but the LLCC was still not embedded in the CDO feature. The center was
estimated to be located near the southwestern edge of the cold cloud
canopy. The MSW was upped to 45 kts in the 0300 UTC advisory, and this
intensity was maintained in the 0900 UTC advisory package. The cyclone
was moving northward around the western periphery of a mid-level ridge
that extended from the Atlantic westward across the Florida Peninsula
into the Gulf of Mexico.
A reconnaissance flight into the storm during the morning found peak
flight-level winds of 66 kts southeast of the center at 1330 UTC and a
central pressure of 1001 mb. Based on this, Bill's intensity was
increased to the peak of 50 kts at 1500 UTC. The storm by this time was
centered only 45 nm south-southwest of Morgan City and closing in on the
Louisiana coastline. As Bill approached the coast, the storm's motion
became northeastward, and by 2100 UTC the center was making landfall
over Terrebonne Bay about 25 nm (40 km) east of Morgan City. Bill was
then moving northeastward at 8 kts with the intensity still estimated
at 50 kts. A weather station in the area measured a MSLP of 997 mb
as Bill was making landfall.
By 0300 UTC on 1 July, the center of Bill was inland just west of
Bogalusa, Louisiana, moving north-northeastward at 8 kts. The MSW had
dropped to 40 kts, mainly over water to the southeast of the center.
The Slidell/KLIX radar indicated Doppler velocities of 50-60 kts just
a few hundred feet above the surface. Tropical Storm Bill was down-
graded to a 30-kt tropical depression at 01/0600 UTC when located near
Hattiesburg, Mississippi. At 0900 UTC the depression was located about
65 km south-southwest of Meridian, Mississippi, moving northeastward
at 12 kts. Some fairly strong wind gusts were still affecting the
coastal region from eastern Louisiana to the Florida Panhandle. The
final TPC/NHC advisory on Tropical Depression Bill was issued at 1500
UTC on 1 July, placing the center near Tuscaloosa, Alabama. Maximum
sustained winds were estimated no more than 20-25 kts.
Responsibility for issuing information on the remnants of Bill was
then assumed by the Hydrometeorological Prediction Center (HPC) at
Camp Springs, Maryland. Bill's slowly weakening remnants continued to
move generally northeastward across the southeastern U. S., passing near
Rome, Georgia, around 0300 UTC on 2 July and later near Knoxville,
Tennessee. By 0300 UTC on the 3rd the LOW was passing about 55 km
northeast of Danville, Virginia, and six hours later was about the same
distance southeast of Washington, DC. By 1500 UTC all that remained
was an elongated surface LOW along a stationary front with winds less
than 10 kts. The lowest surface pressure was near Annapolis, Maryland,
although the most impressive cyclonic circulation in satellite imagery
was located in central Virginia associated with the upper-level LOW
which had been coupled with Bill's remnants for the past 36 hours.
The LOW subsequently moved out over the Atlantic and headed northeast-
ward just off the Mid-Atlantic and New England coastlines. After moving
back out to sea, winds picked up some, reaching 30 kts by 04/0000 UTC.
According to Kevin Boyle, who followed the extratropical remnants of
Bill, the system was located about 250 nm east-southeast of Cape Race,
Newfoundland, around 0000 UTC on 6 July. Moving more quickly towards
the east-northeast, the weakening LOW passed well north of the Azores
on the 7th. By the next day a much larger LOW was becoming dominant,
moving from Newfoundland into the mid-North Atlantic early on 9 July.
Bill's remnant LOW was located within the warm sector of this much
larger circulation. Bill's remains lost its identity on 9 July roughly
300 nm west of Ireland. However, the left-over moisture of the former
tropical storm brought a hot and humid airmass to the UK on the 9th and
10th of July. (Thanks to Kevin for sending this tidbit of information.)
C. Meteorological Observations
------------------------------
(1) Wind Reports
----------------
As Tropical Storm Bill made landfall over southeastern Louisiana on
the afternoon and evening of 30 June, several stations reported sustained
winds exceeding gale force. Louisiana State University maintains some
automated weather stations south of Houma, and one of these recorded
peak sustained winds of 41 kts, gusting to 48 kts, around 30/1800 UTC.
Shortly before 2100 UTC, two of these LSU-maintained stations reported
winds to 43 kts, gusting to 52 kts.
An AWS on the Lake Pontchartrain Causeway recorded a gust of 53 kts
around 0000 UTC on 1 July, and a gust of 47 kts was reported by the
New Orleans International Airport at around the same time. Around 0300
UTC, the Gulfport, Mississippi, airport recorded a sustained wind of
32 kts, gusting to 45 kts.
(All the above information was gleaned from the public advisories issued
by TPC/NHC.)
(2) Rainfall Amounts
--------------------
The following rainfall information was obtained from the storm
summaries issued by HPC after that agency had assumed responsibility
for issuing bulletins on Bill.
(a) Three-day rainfall totals exceeding 5 inches (127 mm) for the
72-hour period ending at 1800 UTC on 1 July:
State Location Total (in) Total (mm)
-----------------------------------------------------------------
LA Mandeville Lakefront 9.22 234
LA Hammond 8.40 213
LA Slidell 7.05 179
LA New Orleans Lakeside 6.62 168
LA New Orleans Intl Arpt 5.54 141
MS Pascagoula 8.85 225
MS D'Iberville 5.64 143
AL Robertsdale 7.46 189
AL Dauphin Island 6.80 173
FL Pensacola Naval Air Station 9.80 249
FL Crestview 5.44 138
Almost all of the heavy precipitation associated with Bill in the
coastal region lay to the east of the storm's track. Baton Rouge, LA,
which lay northwest of the track, received a 3-day total of only
1.84 inches, or 47 mm.
(b) Two-day rainfall totals exceeding 4 inches (102 mm) for the 48-hour
period ending at 1400 UTC on 2 July:
State Location Total (in) Total (mm)
-----------------------------------------------------------------
GA Gainesville 4.24 108
AL Coden 6.78 172
AL Bay Minette 6.58 167
AL Mobile 6.29 160
(c) One-day rainfall totals exceeding 3 inches (76 mm) for various
24-hour periods:
State Location 24 hours ending Total (in) Total (mm)
-------------------------------------------------------------------------
MS Hattiesburg 0000 UTC 2 July 3.38 86
AL Auburn 0000 UTC 2 July 4.35 110
AL Calera 0000 UTC 2 July 3.31 84
AL Evergreen 0000 UTC 2 July 3.27 83
GA Gainesville 0000 UTC 2 July 3.72 94
GA Peachtree City 0000 UTC 2 July 3.14 80
GA Rome 0000 UTC 2 July 3.09 78
GA Atlanta 0000 UTC 2 July 3.02 77
SC Florence 0000 UTC 3 July 3.12 79
SC Darlington 0000 UTC 3 July 3.09 78
VA Charlottesville 1200 UTC 3 July 5.01 127
Jacksonville, NC, recorded a six-hour total of 4.09 inches, or
104 mm, between 1200 and 1800 UTC on 2 July.
D. Damage and Casualties
------------------------
In addition to the coastal flooding and heavy rain, Tropical Storm
Bill produced at least five confirmed tornadoes. One of the tornadoes
struck Reserve, Louisiana, damaging 20 mobile homes and injuring four
people. The total damage estimate for Bill is currently placed at
$30 million, and four deaths have been attributed to the storm.
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for June: 2 tropical storms
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 June
--------------------------------------------
On average the Northeast Pacific basin produces two tropical storms
during the month of June with one reaching hurricane intensity. This
year, two storms developed but neither reached hurricane status, so the
overall level of tropical cyclone activity was a little below normal.
Tropical Storm Blanca developed around mid-month off the Mexican coast
southeast of Manzanillo and drifted erratically for several days,
eventually dissipating not too far from its point of origin. A few days
later short-lived Tropical Storm Carlos popped up southeast of Acapulco,
and instead of following the forecast west-northwestward track parallel
to the Mexican coastline, moved northward and inland near Puerto
Escondido. Carlos was showing hints of an eye as it made landfall, and
another 12 to 18 hours over the warm Pacific waters would likely have
resulted in Carlos reaching hurricane intensity. Reports on Blanca and
Carlos, written by John Wallace, follow. (A special thanks to John for
his assistance.)
Another tropical disturbance deserves mention. As the month of May
closed, a large area of disturbed weather southeast of Acapulco began to
show some signs of organization. The system drifted northward toward
the coast and by the afternoon of 1 June was centered roughly 100 nm
south-southeast of Acapulco and had become better organized. A potential
for tropical depression development was noted in the Tropical Weather
Outlooks issued by TPC/NHC, but the broad center reached the coast near
Acapulco by late in the day, thereby putting the brakes on any further
intensification. However, the attendant heavy rainfall posed a threat
of flooding and landslides over a wide area for several days as the
weakening disturbance moved slowly northward.
TROPICAL STORM BLANCA
(TC-02E)
17 - 22 June
-----------------------------------------
A. Storm History
----------------
The disturbance that became Blanca was first visible just off the
Mexican coast south of Acapulco late on 15 June. Cyclonic organization
was definitely evident the following day, and the LOW steadily organized
until it was upgraded to Tropical Depression Two-E at 0300 UTC on
17 Jun when located about 175 nm south-southeast of Manzanillo, Mexico.
Steering currents were very weak in its vicinity, which was a little
unusual for its time of year and position. Nevertheless, they were able
to impart an initially slow northwesterly motion.
The overall environment of Two-E was not conducive to much
strengthening: its proximity to land threatened it with dry air
entrainment, it was close to unfavorably cool waters, and modest
easterly shear impeded its development at first. Even so, Two-E
organized enough to warrant its upgrade to Tropical Storm Blanca by
2100 UTC on 17 June when centered approximately 165 nm south-southeast
of Manzanillo, and according to the NHC, a TRMM pass had already
indicated a partial low-level eyewall at 1945 UTC that day. That said,
Blanca's convection waxed and waned in a diurnal pattern that made its
intensification slow and occasionally uncertain, especially once
persistent easterly shear impinged on the circulation. This upper-level
easterly current was in fact the main factor in pushing Blanca on a slow
westward track, away from its originally threatening northwesterly one.
This picayune tropical cyclone--with gale-force wind radii of only
40 to 50 nm--was tough, however, and endured the shear enough to reach
its peak MSW of 55 kts, with an estimated CP of 997 mb, at 0300 UTC on
19 June. At the time of its peak intensity Blanca was centered about
150 nm south-southwest of Manzanillo.
Blanca began a weakening trend immediately after its peak, due to a
combination of shear and cooler SSTs across its track. Much as during
its intensification phase, Blanca's decline was slow and uncertain as
its convection and organization fluctuated day by day. In fact, whether
Blanca truly weakened at all is open to debate--it may have had a second
peak around 1400-1600 UTC on the 19th when the NHC noted that multi-
spectral satellite imagery revealed a "low and mid-level eye feature"
(1). Similar convective cycles enabled Blanca to hold on to tropical
storm strength until 2100 UTC on 20 June, when its low and mid-level
circulations were decoupled by the easterly shear. The depression
drifted very slowly westward in erratic, stop-start fashion, with
occasional bursts of convection that kept it alive longer than expected.
Late in its life the depression actually took an unusual drift to the
east as it became caught up in low-level southwesterly flow off the
Mexican coast. The final advisory on Tropical Depression Blanca was
issued at 1500 UTC on 22 June. Vague hints of its vortex remained
visible offshore in satellite imagery until late the following day.
B. Damage and Casualties
------------------------
There are no known casualties or damages associated with Tropical
Storm Blanca.
C. References
-------------
(1) http://www.nhc.noaa.gov/archive/2003/dis/ep022003.discus.013.shtml?>
(Report written by John Wallace)
TROPICAL STORM CARLOS
(TC-03E)
26 - 27 June
-----------------------------------------
A. Storm History
----------------
The precursor disturbance of Carlos was first noted as a cyclonic
whorl of convection in the Pacific southwest of Nicaragua in satellite
imagery taken late on 23 June. The LOW uneventfully tracked slowly
west-northwestward over the next two days with little change in
organization until late on the 25th, whereupon it was upgraded to
Tropical Depression Three-E at 0300 UTC on 26 June when it was roughly
175 nm south-southeast of Acapulco, Mexico.
The new depression was not in an ideal environment, due to possible
interference from land and modest northeasterly shear. Though it was
forecast to parallel the Mexican coast, its proximity warranted the
issuance of watches and warnings for the coast upon its upgrade. The
cyclone defied the forecasts, however. The ridge that was predicted to
steer the system out to sea did not materialize as soon as expected, and
Three-E drifted northward as it strengthened to Tropical Storm Carlos
at 1800 UTC on 26 June roughly 155 nm southeast of Acapulco. Synoptic
conditions became more favorable, and Carlos strengthened quickly,
reaching its peak MSW of 55 kts, with an estimated CP of 994 mb, as it
made landfall at 0600 UTC on the 27th at a location roughly 25 nm north-
west of Puerto Escondido, Mexico. Carlos nearly became a hurricane;
NHC discussions around the time of landfall state that a well-defined
eye was present as it crossed the coast, so the 55-kt estimate may well
be conservative.
Carlos dissipated rapidly over the mountainous terrain of Mexico as
it turned west-northwestward and accelerated slightly. Though a LLCC
was doubtful by 1500 UTC on the 27th (1), the NHC kept the system in
advisory status until 2100 UTC that day when they issued the last
advisory on Tropical Depression Carlos. Carlos' remnant vortex drifted
offshore, and retained cyclonic structure until late on the 30th when it
finally dissipated.
B. Damage and Casualties
------------------------
There are some reports of a few casualties resulting from Carlos,
but unfortunately there is no solid official data available on them at
the present time.
C. References
-------------
(1) http://www.nhc.noaa.gov/archive/2003/dis/ep032003.discus.007.shtml?>
(Report written by John Wallace)
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for June: 1 typhoon
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.
Northwest Pacific Tropical Activity for June
--------------------------------------------
Only one tropical cyclone formed in the Northwest Pacific basin during
June, but it was a very impressive one. Typhoon Soudelor (named Egay by
PAGASA) formed shortly before mid-month deep in the tropics well to the
east of the Philippines. The cyclone moved westward, then took a jog
northward as it neared the Philippine archipelago, moving roughly
parallel to the islands from Samar to northeastern Luzon. After moving
past Luzon, Soudelor/Egay finally reached typhoon intensity, steadily
intensifying as it moved northward east of Taiwan. Peak intensity of
115 kts was reached as Soudelor passed west of Okinawa. After that, the
storm turned north-northeastward as it began to weaken and passed through
the narrow slot between South Korea and Japan into the Sea of Japan where
it became extratropical. A full report on Typhoon Soudelor follows,
written by Kevin Boyle with some additional material from Huang Chunliang
and Karl Hoarau. (A special thanks to all these gentlemen for their
assistance and inputs.)
One other tropical storm was active in Western Pacific waters during
June. On 1 June Tropical Depression 06W (named Dodong by PAGASA), which
had formed in the South China Sea in late May, was upgraded to Tropical
Storm Nangka. Nangka subsequently followed a northeasterly track through
the Luzon Strait, passing between Luzon and Taiwan, and soon lost its
tropical characteristics east of Taiwan. The full report on Tropical
Storm Nangka/Dodong can be found in the May summary.
TYPHOON SOUDELOR
(TC-07W / TY 0306 / EGAY)
11 - 23 June
---------------------------------------------
Soudelor: submitted by Micronesia, is the name of a legendary
Pohnpei chieftain
Egay: PAGASA name, is a Filipino female nickname
A. Storm Origins
----------------
The summary for the eventful Typhoon Soudelor begins at 2100 UTC,
9 June. At this time JTWC issued a TCFA for a circulation centre
located near 8.9N, 145.5E (approximately 270 nm south of Guam). The
position was based on 09/1730 UTC satellite imagery. Animated enhanced
infrared satellite imagery revealed that deep convection continued to
organize around the well-defined LLCC while a 09/1650 UTC TRMM pass
showed organizing low-level cloud lines associated with the LLCC. Upper-
level analysis showed a favourable wind shear pattern but with marginal
outflow aloft. The system was moving westward at 10 kts with an
estimated MSW and CP of 20-25 kts and 1004 hPa, respectively. By 10/2100
UTC the disturbance had continued westward to a position approximately
210 nm east of Yap (9.7N, 141.8E). Animated infrared satellite imagery
by then revealed decreasing deep convection over an exposed LLCC. Upper-
level analysis was at this time depicting low to moderate vertical wind
shear with poor diffluence aloft. Based on this JTWC opted to issue a
second TCFA rather than writing the first warning.
JTWC issued the first warning on Tropical Depression 07W at 1800 UTC
on 11 June after satellite CI estimates had reached 25 kts with the
system exhibiting a 0.2 spiral band wrap. The depression was near 9.4N,
137.3E, or approximately 50 nm west of Yap, moving westward at 14 kts.
The system continued to slowly develop through the 12th, although a
12/1214 UTC SSM/I pass and recent enhanced infrared satellite animation
revealed a rather weak and disorganized system with the LLCC difficult to
pinpoint with confidence. By 1800 UTC, however, TD-07W began to compose
itself with animated enhanced infrared satellite imagery, 12/1657 UTC
AMSU and 12/1538 UTC TRMM passes indicating a 0.4 spiral band wrap.
TD-07W began to move more northwestward at a slower pace (6 kts) for
awhile in response to interaction with a cyclonic circulation centred to
the east-southeast near 8.8N, 138.9E. (JTWC issued a STWO statement on
this LLCC at 13/0100 UTC, assessing the development potential as poor.)
The fact that TD-07W was still located in a monsoon trough environment
and the close proximity of the second disturbance likely inhibited
development.
B. Storm History
----------------
By 13/0000 UTC TD-07W began to move west and further from the
hindering cyclonic circulation, and in response to this, the MSW
increased first to tropical storm strength, then to 45 kts six hours
later. At 13/0000 UTC JMA upgraded the LOW to a 30-kt tropical
depression in their High Seas bulletins, and upgraded to tropical storm
intensity twelve hours later, assigning the name Soudelor. (NMCC, CWBT
and PAGASA had by this time all upgraded Soudelor to tropical storm
intensity.) Animated multi-spectral satellite imagery showed well-
defined spiral bands on both equatorward and poleward sides. This
strengthening phase was thwarted by a TUTT cell located to the east, and
at 1800 UTC the MSW had increased only 5 kts more to 50 kts. The system
was also beginning its approach towards the Philippines at this time.
PAGASA had begun issuing warnings on the system at 12/1800 UTC, naming
the system Egay, the Filipino name for the cyclone.
At 0000 UTC on 14 June Tropical Storm Soudelor/Egay was located
85 nm east of Samar, Philippines, or near 12.2N, 127.1E, with the MSW
easing a little to 45 kts. At this time the cyclone was moving westward
at 10 kts. The Prognostic Reasoning issued by JTWC at 14/0000 UTC fore-
cast a more northerly heading within 24 hours as a longwave trough off
the Chinese coast dug into the mid-level ridge northeast of Soudelor.
This forecast verified and by 15/0000 UTC, Soudelor was moving toward
the north at 10 kts in response to the developing weakness. The
intensity of Soudelor/Egay had remained steady at 45 kts through the
14th, and microwave imagery revealed a partially-exposed LLCC at the
northern edge of the deep convection.
There was nothing more to add as the 15th dawned. The MSW remained
at 45 kts and the LLCC was still partially-exposed. At 0000 UTC Tropical
Storm Soudelor was located 130 nm northeast of Samar (14.2N, 126.6E),
moving north at 10 kts. By 15/1200 UTC things had begun to liven up when
animated enhanced infrared satellite imagery showed an increase in deep
convection over the LLCC. Based on satellite CI estimates of 45 kts and
55 kts, JTWC increased the MSW to 55 kts, and six hours later to 60 kts.
During the 15th and into the 16th, Soudelor/Egay was stair-stepping its
way north or northwestward (at around 10 kts) along the western periphery
of the mid-level ridge to the east. This path took the storm roughly
parallel to the Philippines' northeastern coastline and into HKO's AOR
at 15/1800 UTC with that agency then initiating warnings. A 15/2203 UTC
SSM/I pass showed that the deep convection had continued to organize
around the LLCC. Spiral bands were wrapping into the system from the
south, and outflow conditions were improving with the longwave trough
aiding diffluence to the north of the system. After remaining at 60 kts
intensity for much of the 16th, Soudelor finally became a typhoon at
16/1800 UTC. (JMA did not upgrade Soudelor to typhoon intensity until
17/1200 UTC.) A 16/1330 UTC SSM/I 37-GHz pass revealed a well-defined
15-nm banding eye. The newly-upgraded typhoon was beginning to link up
with the approaching longwave trough to the west, and this system was to
drag Soudelor off on a north or northeasterly track which would take it
towards the southern Japanese island chain. At 16/1800 UTC the eye was
fixed uncomfortably close (50 nm) to the northeastern coastline of Luzon
near 19.0N, 122.9E with the MSW estimated at 65 kts.
Strengthening continued as the typhoon began to pull away from the
Philippines. (Soudelor/Egay left PAGASA's AOR at 18/0000 UTC and HKO's
AOR at 18/0600 UTC.) The MSW had increased to 75 kts by 0000 UTC,
17 June, and animated multi-spectral satellite imagery revealed a ragged,
irregular-shaped 30-nm eye. The diameter of the eye shrunk to 12 nm as
the MSW increased to 90 kts by 1800 UTC later that same day. At 1800
UTC, Typhoon Soudelor was passing to the east of Taiwan with the outer
portion of the circulation setting off thunderstorm activity as seen in
satellite animation. The intensification phase lasted into the 18th and
a peak intensity of 115 kts was reached at 18/0600 UTC. (JMA's peak
intensity of 80 kts (10-min avg) with an estimated CP of 955 mb occurred
at 18/1200 UTC.) A symmetrical 18-nm eye was noted in multi-spectral
imagery at this time. The system had by then moved to a position 190 nm
west of Naha, Okinawa (26.3N, 124.2E), trekking northward at 13 kts and
heading toward Japan. Upper-level analysis indicated that opportunities
for further strengthening were dwindling fast and that the typhoon had
already entered a region of unfavourable wind shear. By 1800 UTC the
spiral bands took on a more ovate appearance, the eye faded, and the MSW
dropped to 85 kts.
The downward spiral continued. The 0000 UTC, 19 June JTWC warning
located the centre of Soudelor near 32.5N, 128.5E, or 70 nm southwest of
Sasebo, Japan. Water vapor imagery indicated that the system was
beginning to resemble a cold-core mid-latitude system. The MSW had
fallen to 75 kts and continued to decrease, falling below typhoon-force
at 19/0600 UTC as Soudelor trekked west of Japan, past the southeastern
coast of South Korea, and into the Sea of Japan. JTWC downgraded
Soudelor to a tropical storm at 19/1200 UTC and declared it extratropical
six hours later. The final warning placed the centre 160 nm northwest of
Wajima, Japan, or near 39.7N, 134.9E. JMA ended warning transmissions
at 19/1800 UTC. The extratropical remnants of once-powerful Typhoon
Soudelor turned eastward, crossing northern Japan, and were last
referenced at 0000 UTC on 23 June as a weakening 25-kt LOW far to the
east of Honshu.
C. Meteorological Observations
------------------------------
Karl Hoarau forwarded the following rainfall observations from the
Philippines. (Thanks to Karl for passing along this information.)
(1) 24-hour period from 0000 UTC June 14th to 0000 UTC June 15th:
WMO 98546 Catarman (12.65N, 124.6E) 330mm (13 inches)
WMO 98550 Tacloban (11.2N, 125E) 155mm (6.1 inches)
WMO 98447 Virac radar (13.7N, 124.3E) 87mm (3.4 inches)
WMO 98444 Legaspi (13.1N, 123.8E) 50mm (1.96 inches)
(2) Six-hour total from 0000 UTC to 0600 UTC 15th June:
WMO 98440 Daet (13.5N, 123.3E) 98mm (3.88 inches)
WMO 98444 Legaspi (13.1N, 123.8E) 31mm (1.22 inches)
WMO 98446 Virac airport (13.6N, 124.2E) 118mm (4.65 inches)
WMO 98447 Virac radar (13.7N, 124.3E) 64mm (2.52 inches)
(3) The lowest recorded sea level pressure was 997.3 hPa at Casiguran
(WMO 98336 - 16.3N, 122.1E) at 1000 UTC 16 June. Some other
pressure readings include:
WMO 98447 Virac radar (13.7N, 124.3E) 999.4 hPa at 15/0500 UTC
WMO 98233 Tuguegarao (17.6N, 121.7E) 997.5 hPa at 16/0800 UTC
WMO 98232 Aparri (18.4N, 121.6E) 998.1 hPa at 16/1000 UTC
Huang Chunliang has sent some wind observations from station
Iriomotejima, Okinawa (WMO 47917 - 24.4N, 123.8E). (Thanks to
Chunliang for sending this information.)
Iriomotejima experienced sustained gale-force winds (10-min avg)
at least from 17/2000 UTC through 18/0400 UTC with the exception of
17/2100 UTC when the station was in the typhoon's eye. The peak hourly
MSW of 56 kts occurred at 2200 UTC shortly after passage of the eye.
The minimum SLP of 968.1 hPa occurred around 2100 UTC during eye
passage. Regarding the peak gust, Chunliang indicates that the maximum
he could find was 104 kts. However, Section E is an analysis of
Soudelor's intensity by Karl Hoarau, and he references a peak gust of
110 kts at Iriomotejima.
D. Damage and Casualties
------------------------
Heavy rains unleashed by Typhoon Soudelor/Egay are known to have
caused 11 deaths and 3 injuries in the Philippines. At last report,
two persons were still missing. The Department of Social Welfare and
Development declared on 17 June that 16,131 families had been displaced
in the northern and central provinces of Sorsogon, Albay, Catanduanes
and Camarines Sur by floods caused by the torrential downpours associated
with Soudelor.
Heavy rains also caused flooding, landslides, and mudflows in Taiwan.
One of the major highways connecting Hsitou and Luku was blocked when a
10-km stretch of road in Nantou County was covered by debris and mud.
Taipei's Sungshan Airport was forced to close three times as a result of
the bad weather. There are no reports of casualties.
A North Korean ship cargo loaded with industrial magnesium was
stranded off the northwest coast of Japan after being refused entry into
the Japanese port of Toyama. The Suyangsan had failed a safety check
and had no lifeboats. The 874-ton vessel, with a crew of 16, had been
anchored since 12 June and lay in the path of Typhoon Soudelor.
Negotiations were being made between the captain and Toyama authorities
for refueling arrangements. It is unknown what the final outcome was.
Twenty-one storm-related injuries were reported in Japan as a result
of Soudelor, mostly people struck by falling objects. None were serious.
Damage statistics appear to have been light in Japan. However, there
was damage to 26 houses: mainly dislodged tiles, broken windows, and
shattered walls. Nearly 10,000 households were left without
electricity. Transportation was disrupted with numerous flight
cancellations. Train services in northern Kyushu were halted because of
the bad weather.
E. Analysis of Soudelor's Intensity
-----------------------------------
The following was sent to me by Dr. Karl Hoarau. It is an analysis
of Soudelor's intensity near the time of its passage over the station
of Iriomotejima (WMO 47917 - 24.8N, 123.8E). I have reproduced it
just as Karl sent it with some minor editing. (A special thanks to
Karl for sending his analysis.)
"There are some interesting features to notice when Typhoon Soudelor
passed through the small Japanese islands on 17 June. Iriomotejima
recorded a maximum gust of 110 kts from east-northeasterly winds in
the northern eyewall. At 17/2100 UTC, while located in the elongated
eye (12 x 7 nm) of Soudelor, the station recorded a minimum sea-level
pressure of 968.1 hPa with winds of 7 kts. The gust of 110 kts
corresponds to a MSW (1-min avg) of 90 kts. The pressure/wind relation-
ship of Atkinson and Holliday (1977) still used in the NWP gives a CP
of 954 hPa for 90 kts. A possible explanation for this feature is the
small size of Soudelor's core. At 2100 UTC, situated 19 nm east of the
eye's center, Ishigakijima recorded a SLP of 983.5 hPa and a 10-min avg
wind of 42 kts (50 kts at 1900 UTC when the eye's center was 35 nm to
the southwest). The station just missed the eastern eyewall as Soudelor
was moving to the north-northeast at 13 kts. Most of the time for this
type of track, the strongest winds are located in the eastern eyewall.
But the F14 SSM/I overpass at 18/0014 UTC showed that the strongest
convection was situated in the north and northwest portions of the
eyewall. So, the intensity of the typhoon was probably near 90 or
95 kts if we consider that it is not certain if Iriomotejima recorded
the strongest winds.
"The Dvorak manual (subjective) T-numbers were at least 5.0 after
1400 UTC, and at 5.5 from 2000 UTC to 0230 UTC on the 18th. When Typhoon
Soudelor passed over Iriomotejima at 2100 UTC, it displayed an Off-White
embedded in a White ring. As the eye was elongated, a raw satellite Data
T-number of 6.5 could not be retained. In fact, there is a rule in the
Dvorak method (1984) about that: no plus adjustment can be made for
large eyes (> 3/4 degree diameter within the surrounding Gray shade) or
for elongated eyes. When no previous subtraction is made, 0.5 can be
subtracted for elongated eyes having E (eye) numbers > 4.5. Elongated
eyes are defined as those having a short axis < 2/3 the long axis within
the surrounding Gray shade. Therefore, the raw data T-number was 5.5
at 2100 UTC. As Soudelor possessed an elongated eye most of the time
until 18/0000 UTC, the satellite data T-number reached 6.0 only for 2-3
hours before that time and never after.
"It appears the typhoon reached its peak around 18/0230 UTC with a
warm (+19.7 C) and circular eye embedded in a Light Gray ring (raw data
T-number of 5.5 for the last time). The visual picture revealed that
the CDO had a 92-nm diameter. It is certain that after 2100 UTC on
17 June Soudelor kept on intensifying. At 2200 UTC, the pressure was
still 970.7 hPa at Iriomotejima (968.1 hPa in the eye at 2100 UTC)
when the center was 12 nm distant. Located in the southern eyewall,
the station recorded a sustained wind of 60 kts (10-min avg). This is
an indication that the pressure was still falling."
In summary, Karl indicates that his estimate for the peak intensity
of Soudelor was 105 kts at 18/0600 UTC (JTWC's estimate was 115 kts
at that hour).
(Report written by Kevin Boyle with contributions by Huang Chunliang
and Karl Hoarau.)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for June: No tropical cyclones
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for June: No tropical cyclones
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for June: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for June: 1 tropical cyclone of gale intensity
1 interesting hybrid storm system
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northeast Australia/Coral Sea tropical cyclones are the warnings
and advices issued by the Tropical Cyclone Warning Centres at
Brisbane, Queensland, and Darwin, Northern Territory, and on very
infrequent occasions, by the centre at Port Moresby, Papua New
Guinea. References to sustained winds imply a 10-minute averaging
period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Northeast Australia/Coral Sea
Tropical Activity for June
------------------------------
In May, 2002, Tropical Cyclone Upia became the first tropical cyclone
to be named by the Port Moresby, PNG, tropical cyclone warning centre
in their small AOR in nine years. But they had only one year to wait
before naming the next. Tropical Cyclone Epi formed on 5 June deep in
the tropics east of New Guinea and south of New Britain. Epi, however,
had a short life of only 12 hours as a tropical cyclone before being
downgraded to a depression. A report on Tropical Cyclone Epi is
included below, written by Simon Clarke. (A special thanks to Simon
for his assistance.)
Also included is a report on an interesting hybrid storm system off
the Queensland coast in late June which brought strong winds and heavy
rainfall to portions of the Queensland and New South Wales coastlines.
TROPICAL CYCLONE EPI
5 - 7 June
----------------------------------------
Tropical Cyclone Epi was the first tropical cyclone of the season to
develop in the small AOR of the TCWC at Port Moresby, Papua New Guinea.
Epi follows Tropical Cyclone Upia, which formed in a similar location
late in the 2002 season. (A description of Upia can be found in the
tropical cyclone summary for May, 2002)
Epi formed at approximately 0630 UTC, 5 June 2003, near 7.9S, 152.9E,
or about 50 nm northwest of Woodlack Island, from an area of fairly
persistent convection stretching from New Guinea across toward the
north of Fiji. Epi was a very short-lived cyclone, and was in all
likelihood hampered in its development by a strengthening tropical LOW
to its southeast. This tropical LOW eventually developed into a
tropical cyclone and was named Gina. (A report on Gina follows in the
section of this summary covering the South Pacific basin.) The second
PNG warning at 05/1100 UTC placed Epi's centre about 65 nm northeast
of Woodlack. The third and final warning at 05/1800 UTC located the
weakening system about 40 nm east of the 1100 UTC position with winds
having fallen below gale force.
Jeff Callaghan from the Queensland Bureau of Meteorology makes the
following observations (note some text editing for clarity):
"The ascending QuikScat image shows a LOW developing on the south-
western end of a shear line. The satellite infrared sequence (Dvorak
enhancement) shows the development of a large curved band following
the QuikScat pass. This band proceeded to be a feature during most
of the daylight hours and had a 0.7 or 0.8 wrap (depending on the
analyst). So it looked like a rapidly developing cyclone. There was
no coverage over the system from the descending QuikScat pass, and
after this the cloud features began to break up around 05/1400 UTC
when strong northeasterly upper-level winds developed over the centre.
Initially, the system appeared to be moving slowly west. However,
Epi then paused and moved toward the east (indicating possible inter-
action with Gina). This resulted in Epi's demise and weakening below
cyclone status."
Convection persisted in the vicinity of the former Tropical Cyclone
Epi for several days. However, proximity to Gina ensured that conditions
remained unfavourable for redevelopment.
It is not clear exactly how intense Epi became during its life. A
minimum central pressure of 985 hPa was advised, probably based on
Dvorak analysis which showed a curved band pattern with a 0.8 wrap
giving a T3.5. This intensity may in hindsight have been an over-
estimation. It is noted that southwest winds of 30 kts between New
Ireland and Bougainville were verified by two ships, giving credence
to the presence of an area of gales under the deep convection.
With respect to intensity, Jeff Callaghan points out the problem in
these parts is that cyclones develop very rapidly in an area where
there is almost no data. Rapidly developing cyclones in this area can
be a major problem and have caused much loss of life. On some occasions
destruction has occurred without warnings being issued. So, there is a
need for timely warnings as various islands can quickly come under the
influence of a tropical cyclone. A precautionary approach is therefore
wise in this part of the world, especially considering that in the scheme
of things, cyclones are very rare in this area. (Note: JTWC did not
recognise Epi as a tropical cyclone, although a TCFA was issued at
0900 UTC on 5 June. The TCFA was cancelled at 06/0530 UTC after the
system had weakened.)
Several warnings were issued by the Papua New Guinea National Weather
Service based in Port Moresby with warnings issued for coastal and
island communities between Woodlack Island and Kiriwina Island. Watches
were also issued for the rest of Milne Bay Islands.
No reports of damage or casualties resulting from Tropical Cyclone
Epi have been received.
(Report written by Simon Clarke)
Queensland Hybrid LOW
24 - 26 June
---------------------
A. Storm History
----------------
In late June an interesting meteorological situation developed just
off the Queensland coast. The Brisbane warning centre issued gale
warnings on a LOW from the 24th through the 26th. This system formed
in the tropics but had more of the characteristics of a hybrid storm.
At 1600 UTC on 24 June the LOW was centred about 150 nm east-
northeast of Townsville. The system moved generally southeastward
fairly quickly and by 0600 UTC on the 26th had reached a position
approximately 325 nm east-southeast of Brisbane. The highest winds
forecast in the Brisbane warnings were 45 kts (10-minute mean), but
sustained winds to 53 kts were recorded at Lord Howe Island as the
storm passed just to the west of that station on the 26th.
Bob Hart of Pennsylvania State University examined the storm's
evolution with the cyclone phase space. According to Bob, the system
evolved on 25 and 26 June from a decidedly cold-core, thermally
asymmetric structure to a much more symmetric, shallow warm-core
structure in a fairly short period of time. The system's phase
trajectory was similar to that of some subtropical cyclones in the
North Atlantic (such as the early states of Hurricanes Karen and
Olga in 2001). Jack Beven of TPC/NHC noted that the system initially
had a very baroclinic appearance similar to nor'easters off the U. S.
East Coast, and although it later developed some central convection
and possibly an eye-like feature, it still displayed a pronounced
baroclinic cloud band. The PSU phase space diagrams for the system
can be found at the following link:
http://eyewall.met.psu.edu/cyclonephase/archive/2003>
Another interesting feature of this storm system was a small trough
system which circulated around the parent LOW. This small cyclonic
eddy moved inland into northeastern New South Wales and southeastern
Queensland where it caused localized severe wind damage and brought
torrential rain.
B. Meteorological Observations
------------------------------
(1) Rainfall Reports
--------------------
Matthew Saxby of Queanbeyan, New South Wales, sent me some rainfall
observations he'd obtained. Below are listed 24-hour totals which
exceeded 63 mm (~2.5 inches) for 24, 25 and 26 June. (A special thanks
to Matthew for sending the information.)
24 June: 0000 - 2300 UTC
------------------------
Mt. Charlton, Qld 104 mm
Dalrymple Hts, Qld 80 mm
Mackay, Qld 80 mm
Mirani, Qld 80 mm
Mackay East, Qld 69 mm
Mackay Airport, Qld 63 mm
25 June: 0000 - 2300 UTC
------------------------
Warroo, Qld 66 mm
Ballina Airport, NSW 190 mm
Ballina, NSW 160 mm
Alstonville, NSW 118 mm
Nambucca Heads, NSW 68 mm
Woodburn, NSW 67 mm
Macksville, NSW 66 mm
26 June: 0000 - 2300 UTC
------------------------
Tomewin, Qld 108 mm
Byron Bay, NSW 176 mm
Mullumbimby, NSW 138 mm
Murwillumbah 113 mm
Cape Byron AWS, NSW 107 mm
Ballina, NSW 106 mm
Tweed Heads, NSW 79 mm
(2) Wind Reports
----------------
Jeff Callaghan of the Brisbane TCWC sent along some wind observations
from Lord Howe Island (31.5S, 159.0 E) as the system passed just to the
west of that station. All the observations were taken on 26 June. (A
special thanks to Jeff for passing along the information.)
Time Wind Dir MSW (10-min) MSLP
(UTC) (deg) (kts) (hPA)
---------------------------------------------------
0530 90 40 1004.9
0700 90 41 1000.0
0858 80 48 994.2
0944 80 53 992.8
0956 80 53 991.6
1014 60 50 993.7
1039 50 40 993.8
1057 70 50 992.6
1119 60 48 993.1
1200 50 40 993.5
C. Storm Effects
----------------
Six fishermen from the 25-metre, 80-ton vessel "Tan Sula" were
rescued 32 nm east of Cape Byron on the northern NSW coast on 27 June
by being winched onto two helicopters from Brisbane and Lismore. Seas
on the Gold Coast of Queensland were large with significant wave
heights to 4.3 m at the Brisbane wave rider buoy on 26 June. In NSW
significant heights reached 5.5 m on the 27th at Coffs Harbour. Surfers
were injured by the large waves and there were six major rescues off
the NSW coast by lifeguards.
Rivers overflowed in northern NSW causing flooding around Murwillum-
bah, Mullumbimby and Byron Bay. Police rescued a 14-year old boy at
Stokers Siding, 50 km from Byron Bay, who tried to save a calf from
rising waters and became trapped in a tree. A fire brigade helped to
evacuate children from two schools in the Brunswick region because
buses were unable to cross the flooded roads. The large waves made
river entrances in northern NSW and southern Queensland virtually
impassable.
The small trough system circulating around the larger LOW caused
localized severe wind damage on the southern Gold Coast. Trees were
brought down and a dozen homes were damaged by fallen trees, which
also caused power outages. The Coolangatta AWS recorded 10-min avg
winds to 34 kts for a brief period of less than 30 minutes.
The above information was sent by Jeff Callaghan. Carl Smith, who
lives on the Gold Coast, had the following to say:
"As 'the Duck' (i.e., the larger LOW) passed here well off the
coast and travelling southward, a cyclonic eddy formed closer to the
coast, pushing heavy convective clouds over northeastern NSW, dumping
torrential rains which caused flash floods and landslips. The main
shopping area in Byron Bay was sandbagged to prevent floods damaging
shops, and several towns in the area were flooded up to about 2 metres
deep.
"As the heavy convection moved into southeastern Queensland, gale-
force winds buffetted the Gold Coast for many hours beginning around
midday. I estimated that wind gusts here reached about 70 kts several
times between 3pm and 5pm AEST (0500-0700 UTC), bringing down trees
and power lines. We lost power here at about 4pm. Torrential rain
fell into the evening as the winds eased--power was restored at about
6:15pm."
(Thanks to Carl for his comments).
(Report written by Gary Padgett, based upon inputs from Jeff Callaghan,
Matthew Saxby, Carl Smith, Bob Hart and Jack Beven)
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for June: 1 tropical cyclone of hurricane intensity
Sources of Information
----------------------
The primary sources of tracking and intensity information for
South Pacific tropical cyclones are the warnings and advisories
issued by the Tropical Cyclone Warning Centres at Nadi, Fiji (for
waters north of latitude 25S), and Wellington, New Zealand (for
waters south of latitude 25S). References to sustained winds imply
a 10-minute averaging period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Southern Hemisphere
centres' coordinates by usually 40-50 nm or more. The JTWC warnings
are also the source of the 1-minute average maximum sustained wind
values included in the tracks file. Additionally, information
describing details of satellite imagery and atmospheric circulation
features included in the narratives is often gleaned from the JTWC
warnings.
South Pacific Tropical Activity for June
----------------------------------------
The 2002-2003 tropical cyclone season in the South Pacific east of
160E was the most active and vigorous since the great 1997-1998 season.
Through the end of April, eight tropical cyclones had been named, along
with one visitor from the Brisbane AOR. Six of these cyclones, including
Erica from the Australian Region, were intense tropical cyclones. It
appeared that the season had ended very quietly with short-lived, minimal
Tropical Cyclone Fili in mid-April. However, things took a different
turn in early June. A tropical disturbance in the Solomon Islands began
to intensify, and Tropical Cyclone Gina was named on the 5th. Gina moved
initially southwestward and almost became an intense cyclone as winds
reached 80 kts (90 kts 1-min avg from JTWC). However, as the cyclone
approached the 18th parallel, it turned sharply to the southeast and
weakened very rapidly. In its early formative stages Gina affected the
small island of Tikopia, which was blasted by extremely intense Tropical
Cyclone Zoe in late December. The following report on Gina was authored
by Simon Clarke--a special thanks to Simon for his assistance.
TROPICAL CYCLONE GINA
(TD-17F / TC-29P)
4 - 9 June
-----------------------------------------
A. Storm Origins
----------------
Gina was a rare June cyclone in the Southwest Pacific, and coupled
with Tropical Cyclone Epi, which formed for a short while to Gina's
northwest, brought an unusual conclusion to the most active season
in that basin in five years.
Gina was first identified as a westward-moving depression well to
the northeast of Vanuatu within an area of fairly persistent convection
stretching to the west toward the Solomon Islands. JTWC was quick to
pick up the system, and by late on 4 June 2003 had upgraded the initial
depression to cyclone status (TC-29P) while located some 610 nm east of
Honiara, Solomon Islands. At this time, RSMC Nadi identified the system
as a tropical depression (TD-17F) and commenced issuing advisories and
gale warnings.
B. Storm History
----------------
TD-17 continued to move towards the west-southwest at 5 kts under the
steering influence of the low to mid-level ridge to the south. Under
ever-improving upper-level outflow conditions, Gina was named by RSMC
Nadi at Jun 05/0600 UTC near 11.4S, 169.1E, or approximately 550 nm
east-southeast of Honiara.
During the course of 6 June 2003, Gina gradually increased its forward
momentum to 10 kts while steadily intensifying. By June 07/0000 UTC and
near 15.8S, 163.0E, or about 425 nm south-southeast of Honiara, Gina
attained a CP of 970 hPa and hurricane status with winds of 65 kts. A
ragged cloud-filled eye subsequently became more distinct in satellite
pictures. Organization remained good, although the convection was
diminishing gradually, perhaps in response to the nearby remnants of
Tropical Cyclone Epi.
Peak intensity was attained at Jun 07/1200 UTC with the storm near
16.8S, 162.1E, or approximately 365 nm west-northwest of Port Vila,
Vanuatu. The peak intensity was maintained for 12 hours. Gina had
attained a minimum CP of 950 hPa with a MSW (10-min avg) of 80 kts
close to the centre. At this time Gina was a compact cyclone with a
distinct eye. (JTWC's peak 1-min avg MSW was 90 kts, in excellent
agreement with Nadi's estimate.)
After this time, the cyclone approached a region of stronger shear
and cooler SSTs. Gina slowed its west-southwesterly momentum and
turned toward the southeast and then east-southeast in response to a
short-wave trough approaching from the west, south of 20S.
Gina's demise was rapid with convection torn away from the LLCC to
the southeast by the strong shear. The 08/1800 UTC warning from Nadi
placed the centre of the weakening storm near 18.2S, 164.8E, or about
200 nm west-southwest of Port Vila. However, an interim advisory was
issued at 2200 UTC relocating Gina to a point approximately 200 nm to
the northwest of the 1800 UTC position. This relocation, no doubt,
was based upon the receipt of early morning visible satellite imagery.
By Jun 09/0600 UTC Gina had lost cyclone status near 16.4S, 162.0E, or
approximately 375 nm west-northwest of Port Vila. At the time, the
precise location of the centre was difficult to locate. However, it
was clear that the remnant depression had stalled, becoming almost
stationary. Gale warnings for winds of up to 40 kts associated with
the remnants of Gina were issued through 10/0700 UTC, after which time
the winds eased below gale force.
C. Damage and Casualties
------------------------
Tropical Cyclone Gina was to spend its entire life at sea. In its
early stages of formation, the cyclone was reported to have affected
the island of Tikopia, which was battered by the very intense Tropical
Cyclone Zoe in December, 2002. However, there were no specific reports
of damage or loss of life. The Australian media reported that the vessel
'Grace 2' sailing from Bowen (North Queensland) to Vanuatu foundered
when it encountered Tropical Cyclone Gina on 8 June 2003. A mayday was
broadcast, and in a 3-hour rescue operation, the Indonesian Ship 'Daio
Copihue' picked up the crew while en route from New Zealand to Japan.
(Report written by Simon Clarke)
*************************************************************************
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.
The URL is: http://199.10.200.33/jtwc.html>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2002 Atlantic and Eastern North Pacific
tropical cyclones; also, preliminary storm reports for all the 2002
Atlantic and Eastern North Pacific cyclones are now available, as
well as track charts and reports on storms from earlier years.
The URL is: http://www.nhc.noaa.gov>
A special thanks to Michael Bath of McLeans Ridges, New South Wales,
Australia, for assisting me with proofreading the summaries.
PREPARED BY
Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327
John Wallace (Eastern North Pacific, North Indian Ocean, Western
Gulf of Mexico)
E-mail: [email protected]
Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South
China Sea)
E-mail: [email protected]
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: [email protected]
*************************************************************************
*************************************************************************
|
Document: summ0306.htm
Updated: 27th December 2006 |
[Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] |