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TROPICAL STORM CHANTAL DISCUSSION NUMBER 20
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT MON AUG 20 2001
ALTHOUGH SATELLITE IMAGERY SUGGESTS A SLIGHTLY BETTER-ORGANIZED
SYSTEM THAN 24 HOURS AGO...RECON DATA SHOWS THE CENTER IS STILL
DISPLACED TO THE WEST OF THE MAIN AREA OF DEEP CONVECTION. WHEREAS
THE SHEAR MAY FINALLY BE RELAXING...THERE IS LITTLE TIME FOR
STRENGTHENING BEFORE THE CENTER REACHES THE COASTLINE. HOWEVER ONLY
A MODEST INCREASE IN THE WIND SPEEDS COULD RESULT IN SUSTAINED WINDS
NEAR HURRICANE FORCE. AIR FORCE HURRICANE HUNTER AIRCRAFT WILL
CONTINUE TO CLOSELY MONITOR THE STATUS OF CHANTAL TODAY. ASSUMING
THE SYSTEM WILL EMERGE OVER THE BAY OF CAMPECHE...THERE WILL BE
ANOTHER OPPORTUNITY FOR STRENGTHENING LATER IN THE PERIOD.
WATER VAPOR ANIMATION SHOWS A MID- TO UPPER-LEVEL TROUGH THAT
APPEARS TO BE DIGGING SOUTHEASTWARD. WHEREAS THIS FEATURE WILL
LIKELY WEAKEN THE STEERING FLOW...NUMERICAL GUIDANCE INDICATES THAT
THIS TROUGH WILL NOT BE INFLUENTIAL ENOUGH TO PULL CHANTAL
NORTHWARD. IN FACT...THE LATEST GLOBAL MODEL GUIDANCE SUGGESTS THAT
THE TRACK FORECAST NEEDS A LITTLE MORE SOUTHWARD ADJUSTMENT. THE
OFFICIAL FORECAST IS A BLEND OF THE TRACK GUIDANCE ENSEMBLE...WHICH
SHOWS A FAIRLY CLOSE AGREEMENT OF THE PURELY DYNAMICAL MODELS.
FORECASTER PASCH
FORECAST POSITIONS AND MAX WINDS
INITIAL 20/1500Z 17.7N 86.3W 55 KTS
12HR VT 21/0000Z 18.4N 88.0W 60 KTS...INLAND
24HR VT 21/1200Z 19.3N 90.0W 50 KTS...INLAND
36HR VT 22/0000Z 20.0N 91.5W 45 KTS
48HR VT 22/1200Z 20.7N 93.0W 55 KTS
72HR VT 23/1200Z 21.0N 95.0W 70 KTS
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