11am adv Hurricane Watches issued

[wrkh99]

Tropical Storm Claudette Forecast/Advisory Number 4


Statement as of 15:00Z on July 09, 2003



at 11 am EDT...1500 UTC...the government of Mexico has issued a
Hurricane Watch for the east coast of the Yucatan Peninsula from
Chetumal to Cabo Catoche.

A Tropical Storm Warning remains in effect for Jamaica and Grand
Cayman. A tropical storm watch remains in effect for Little Cayman
and Cayman Brac.


Tropical Storm Claudette Advisory Number 4


Statement as of 11:00 am EDT on July 09, 2003


...Claudette weakens slightly...

at 11 am EDT...1500 UTC...the government of Mexico has issued a
Hurricane Watch for the east coast of the Yucatan Peninsula from
Chetumal to Cabo Catoche.

A Tropical Storm Warning remains in effect for Jamaica and Grand
Cayman. A tropical storm watch remains in effect for Little Cayman
and Cayman Brac.

At 11 am EDT...1500z...the center of Tropical Storm Claudette was
located near latitude 15.5 north...longitude 77.6 west or about
175 miles...280 km...south-southwest of Kingston Jamaica.

Claudette is moving toward the west near 24 mph...39 km/hr. A
gradual turn toward the west-northwest at a slower forward speed is
expected during the next 24 hours.

Reports from an Air Force reserve hurricane hunter aircraft indicate
maximum sustained winds have decreased to near 65 mph...100
km/hr...with higher gusts. Upper level winds are not currently
favorable for development...and little change in strength is
forecast during the next 24 hours.

Tropical storm force winds extend outward up to 160 miles
...260 km mainly to the north of the center.

The latest minimum central pressure reported by the hurricane hunter
is 1004 mb...29.65 inches.
Above normal tides accompanied by large and dangerous battering
waves are expected along the south coast of Jamaica.

Storm total rainfalls of 3 to 6 inches are likely in association
with Claudette. Satellite imagery indicates that rainbands should
be spreading over Jamaica in the next few hours.
Repeating the 11 am EDT position...15.5 N... 77.6 W. Movement
toward...west near 24 mph. Maximum sustained
winds... 65 mph. Minimum central pressurTropical Storm Claudette Discussion Number 4


Statement as of 11:00 am EDT on July 09, 2003



Claudette has weakened some this morning. Southwesterly vertical
shear has caused the center to become intermittently exposed on the
edge of the convection...and a reconnaissance aircraft indicates a
central pressure of 1004 mb along with flight-level winds of 59 kt.
Based on this the maximum winds are reduced to 55 kt...and this may
be a little generous.
The initial motion is 275/21. There is little change in the
synoptic pattern and the forecast philosophy from the previous
package. Claudette remains south of a deep layer subtropical
ridge...whose western end is forecast to weaken after 36 hr as a
deep-layer trough develops over the eastern United States.
Claudette will likely be too far south and west to recurve ahead of
the trough...so the most likely response of the storm is a slow
motion while over the Gulf of Mexico. The track forecast calls for
a gradually decelerating west-northwestward motion through 36-48 hr
as Claudette approaches the western end of the ridge...followed by
a slower northwestward motion over the Gulf of Mexico. This track
forecast is along the southern edge of the dynamical models. It
should be noted that BAMS and nhc98 are south of the current
forecast...but could verify if Claudette weakens further.
Aircraft data shows that the Claudette vortex is rather small...so
there is a distinct possibility that if the shear persists the
system could weaken to an easterly wave. Assuming that does not
happen...large-scale models forecast the upper-level low west of
Claudette to weaken after 12-24 hr and the shear to decrease. The
low appears stronger on water vapor imagery than any of the model
forecasts for 12z...so it will likely hang on longer than the
models currently forecast. Based on this...the intensity forecast
will call for Claudette to change little for the next 24 hr in a
marginal at best environment...followed by strengthening as the
cyclone approaches Yucatan. By the time Claudette reaches the Gulf
of Mexico...a large-scale upper-level anticyclone should be in
place to provide a favorable environment.

Forecaster Beven

e



Tropical storm center located near 15.5n 77.6w at 09/1500z
position accurate within 30 nm

present movement toward the west or 275 degrees at 21 kt

estimated minimum central pressure 1004 mb
Max sustained winds 55 kt with gusts to 65 kt.
50 kt....... 40ne 0se 0sw 40nw.
34 kt.......140ne 25se 25sw 140nw.
12 ft seas..250ne 200se 100sw 140nw.
Winds and seas vary greatly in each quadrant. Radii in nautical
miles are the largest radii expected anywhere in that quadrant.

Repeat...center located near 15.5n 77.6w at 09/1500z
at 09/1200z center was located near 15.4n 76.5w

forecast valid 10/0000z 16.3n 80.5w
Max wind 55 kt...gusts 65 kt.
50 kt... 40ne 0se 0sw 40nw.
34 kt...140ne 25se 25sw 140nw.

Forecast valid 10/1200z 17.6n 83.8w
Max wind 55 kt...gusts 65 kt.
50 kt... 40ne 0se 0sw 40nw.
34 kt...140ne 25se 25sw 140nw.

Forecast valid 11/0000z 19.1n 86.7w
Max wind 60 kt...gusts 75 kt.
50 kt... 50ne 25se 25sw 50nw.
34 kt...140ne 75se 75sw 140nw.

Forecast valid 11/1200z 20.5n 89.0w...inland
Max wind 40 kt...gusts 50 kt.
34 kt...125ne 75se 75sw 125nw.

Forecast valid 12/1200z 22.5n 91.5w...over water
Max wind 45 kt...gusts 55 kt.
34 kt...125ne 75se 75sw 125nw.

Extended outlook. Note...errors for track have averaged near 275 nm
on day 4 and 375 nm on day 5...and for intensity near 20 kt each day

outlook valid 13/1200z 24.0n 93.0w
Max wind 50 kt...gusts 60 kt.

Outlook valid 14/1200z 25.5n 94.0w
Max wind 60 kt...gusts 75 kt.

Request for 3 hourly ship reports within 300 miles of 15.5n 77.6w

next advisory at 09/2100z

forecaster Beven