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TROPICAL STORM CHANTAL DISCUSSION NUMBER  23
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT TUE AUG 21 2001
 
SURFACE OBSERVATIONS FROM CHETUMAL AND BELIZE CITY...ALONG WITH 
RADAR REPORTS FROM BELIZE...INDICATE THAT CHANTAL EITHER STALLED OR 
DEVELOPED A NEW CENTER FURTHER SOUTH AND EAST OF THE PREVIOUS 
ADVISORY POSITION.  IN FACT...THE 08Z RADAR DATA INDICATED AN 
EYEWALL TRYING TO CLOSE OFF BETWEEN SAN PEDRO AND COROZAL.  
SATELLITE DATA ALSO INDICATES THAT DEEP CONVECTION HAS DEVELOPED 
OVER THIS NEW RADAR CENTER...SO THE INITIAL POSITION WAS ADJUSTED 
BACK TO THE EAST.  THE INITIAL INTENSITY WAS DECREASED SLIGHTLY 
BASED ON WIND REPORTS RECEIVED FROM NORTHERN BELIZE AND NEAR 
CHETUMAL.

THE INITIAL MOTION ESTIMATE IS 290/03 BASED ON THE LAST 3 RADAR 
POSITIONS.  DESPITE THE NEARLY STATIONARY MOTION THIS MORNING... 
THERE REMAINS LITTLE CHANGE TO THE TRACK FORECAST PHILOSOPHY. THE
AVN AND UKMET GLOBAL MODELS MAINTAIN THE MID-LEVEL RIDGE TO THE 
NORTH OF CHANTAL THROUGHOUT THE FORECAST PERIOD.  THE LATEST 
FORECAST TRACK IS JUST AND UPDATE OF THE PREVIOUS FORECAST...ALBEIT 
A LITTLE SLOWER TO TAKE INTO ACCOUNT THE RELOCATION OF THE CENTER.  
IT APPEARS THAT ALL OF THE MODELS UNDERESTIMATED THE STRENGTH OF THE 
HIGH AMPLITUDE TROUGH THAT EXTENDS FROM THE NORTHEAST U.S. SOUTHWEST 
INTO THE BAY OF CAMPECHE. SOME ERRATIC MOTION MAY CONTINUE THIS 
MORNING...BUT A RESUMPTION OF A WEST-NORTHWEST TRACK APPEARS TO BE 
IN ORDER GIVEN THE STRENGTH OF THE LOW-LEVEL RIDGE OVER THE GULF OF 
MEXICO.

ONLY SLOW STRENGTHENING IS FORECAST ONCE CHANTAL REACHES THE GULF OF 
MEXICO...ESPECIALLY IF CHANTAL REMAINS OVER THE YUCATAN LONGER THE 
OFFICIAL IS INDICATING.

NOTE...A SPECIAL THANKS IS IN ORDER FOR THE BELIZE MET OFFICE FOR 
PROVIDING SUCH TIMELY AND ACCURATE RADAR REPORTS.
 
FORECASTER STEWART
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     21/0900Z 18.3N  88.3W    55 KTS
12HR VT     21/1800Z 18.7N  89.3W    35 KTS...INLAND
24HR VT     22/0600Z 19.1N  90.2W    35 KTS...INLAND
36HR VT     22/1800Z 19.4N  91.2W    45 KTS
48HR VT     23/0600Z 19.7N  92.3W    55 KTS
72HR VT     24/0600Z 20.0N  94.0W    65 KTS
 
 
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