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TROPICAL STORM CHANTAL DISCUSSION NUMBER  24
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT TUE AUG 21 2001

RADAR OBSERVATIONS FROM BELIZE CITY INDICATE THAT CHANTAL HAS
RESUMED A SLOW WEST-NORTHWESTWARD MOTION DURING THE MORNING...AND
UP TO 13Z HAS MAINTAINED AN IMPRESSIVE SIGNATURE.  INDEED...EVEN
THOUGH THE CENTER IS OVER LAND THE SATELLITE APPEARANCE IS THE BEST
THE STORM HAS EVER HAD.  GIVEN THIS...THE INITIAL INTENSITY WILL BE
LOWERED ONLY TO 45 KT.

DUE TO THE MEANDERING DURING THE NIGHT...THE INITIAL MOTION SOMEWHAT
IS UNCERTAIN WITH THE BEST ESTIMATE 285/5.  WATER VAPOR IMAGERY 
SHOWS A STRONG UPPER LEVEL TROUGH OVER THE EASTERN GULF OF MEXICO...
WHICH MAY HAVE WEAKENED THE RIDGE NORTH OF CHANTAL AND ALLOWED IT
TO SLOW DOWN.  LARGE-SCALE MODELS INDICATE THE TROUGH SHOULD MOVE
EASTWARD DURING THE FORECAST PERIOD...WITH RIDGING INCREASING NORTH
OF THE CYCLONE.  THIS SHOULD ALLOW A FASTER MOTION TOWARD THE
WEST-NORTHWEST OR WEST.  NHC HURRICANE GUIDANCE AGREES WITH THIS
SCENARIO...ALTHOUGH THERE ARE SOME MAJOR DIFFERENCES ON SPEED WITH
THE BAM MODELS AND NHC98 MUCH FASTER THAN THE UKMET AND NHC98UK.
THE OFFICIAL FORECAST WILL BE FASTER THAN AND SLIGHTLY SOUTH OF THE
PREVIOUS PACKAGE...CLOSEST IN SPEED TO THE UKMET.
 
CHANTAL SHOULD WEAKEN TO A DEPRESSION WHILE OVER THE YUCATAN
PENINSULA.  LARGE-SCALE MODELS INDICATE THAT AN UPPER-LEVEL RIDGE
OR ANTICYCLONE SHOULD BUILD OVER THE BAY OF CAMPECHE DURING THE
FORECAST PERIOD...WHICH WOULD GIVE CHANTAL A CHANCE TO STRENGTHEN.
HOWEVER...A CERTAIN SKEPTICISM IS NECESSARY ABOUT THESE FORECASTS
GIVEN THE STRENGTH OF THE TROUGH TO THE NORTH AND RECENT
OVERFORECASTING OF SUCH RIDGING.  THE INTENSITY FORECAST WILL
CONTINUE TO CALL FOR STRENGTHENING...AND THERE IS STILL A CHANCE
THAT CHANTAL COULD BECOME A HURRICANE AS IT APPROACHES THE MEXICAN 
GULF COAST.  ON THE OTHER HAND...GIVEN THE TRACK RECORD OF THE STORM
IT WOULD NOT BE SURPRISING IF IT AGAIN STOPPED SHORT OF HURRICANE
STRENGTH.
 
NOTE...A SPECIAL THANKS IS AGAIN IN ORDER FOR THE BELIZE MET
OFFICE FOR PROVIDING SUCH TIMELY AND ACCURATE RADAR REPORTS.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     21/1500Z 18.5N  89.1W    45 KTS
12HR VT     22/0000Z 18.7N  90.0W    30 KTS...INLAND
24HR VT     22/1200Z 19.1N  91.7W    35 KTS...OVER WATER
36HR VT     23/0000Z 19.5N  93.5W    45 KTS
48HR VT     23/1200Z 19.8N  95.3W    55 KTS
72HR VT     24/1200Z 20.0N  98.5W    35 KTS...INLAND
 
 
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