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TROPICAL STORM CRISTOBAL DISCUSSION NUMBER  11
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT WED AUG 07 2002
 
SATELLITE IMAGERY INDICATES DEEP CONVECTION HAS DEVELOPED IN THE 
EASTERN QUADRANT WITH A NEW CONVECTIVE BAND HAVING DEVELOPED IN THE 
SOUTHERN SEMICIRCLE. DVORAK SATELLITE INTENSITY ESTIMATES ARE 45 KT 
FROM TAFB AND 35 KT FROM SAB AND AFWA. CRISTOBAL LOOKS BETTER NOW 
THAN IT DID WHEN THE LAST RECON FLIGHT WAS IN THE SYSTEM...BUT I 
HAVE OPTED TO HOLD THE INTENSITY AT 40 KT UNTIL THE RECENT 
CONVECTIVE DEVELOPMENT BECOMES SUSTAINED. 
 
THE INITIAL KOTION ESTIMATE IS 090/03...AND THAT IS QUITE GENEROUS 
BASED ON A 12 HOUR MOTION VECTOR. DURING THE PAST FEW HOURS...THE 
CENTER APPEARS TO BE ACTUALLY MOVING SOUTH OR SOUTHWESTWARD...AND SO 
IS THE AFOREMENTIONED DEEP CONVECTION. THE GLOBAL MODELS HAVE 
HANDLED THIS SYSTEM POORLY AT BEST AND THERE WILL COME A TIME WHEN 
WE MAY HAVE TO BAIL OUT ON THE GLOBAL MODELS. THE WORST MODELS SO 
FAR HAVE BEEN THE AVN AND GFDL..IN THAT ORDER. IN 12 HOURS...THE AVN 
HAS CRISTOBAL MOVING NORTHEAST AT 23 KT WHICH SEEMS HIGHLY UNLIKELY 
AT THIS TIME. AS SUCH...I HAVE BAILED ON THE AVN AND GFDL SOLUTIONS 
AND HAVE FOLLOWED THE SLOWER UKMET AND NOGAPS MODELS. INTERESTINGLY 
ENOUGH...THE BEST MODEL HAS BEEN THE MEDIUM BAM MODEL...WHICH TAKES 
THE CYCLONE SLOWLY EASTWARD FOR 24 HOURS AND THEN EAST-NORTHEASTWARD 
TO NEAR BERMUDA IN 72 HOURS. THE BOTTOM LINE IS THAT THE CENTER OF 
CRISTOBAL HAS BEEN FOLLOWING THE CONVECTION THE PAST 2 DAYS AND THE 
CONVECTION HAS BEEN MOVING ONLY SLOWLY TO THE SOUTHEAST DURING THAT 
PERIOD. THE OFFICAL TRACK IS TO THE SOUTH OF AND CONSIDERABLY SLOWER 
THAN THE PREVIOUS FORECAST TRACK. THE POSSIBILITY STILL REMAINS THAT 
CRISTOBAL COULD BECOME CUT OFF FROM THE DEEP WESTERLIES AND MEANDER 
AROUND NORTHEAST OF THE BAHAMAS.

THERE IS NO SIGNIFICANT CHANGE TO THE PREVIOUS INTENSITY FORECAST OR 
REASONING. HOWEVER...12 FT SEAS RADII WERE EXPANDED IN ALL QUADRANTS 
BASED ON 00Z SHIP REPORTS. 
 
FORECASTER STEWART
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     08/0300Z 29.4N  75.2W    40 KTS
12HR VT     08/1200Z 30.1N  73.7W    45 KTS
24HR VT     09/0000Z 31.8N  71.3W    50 KTS
36HR VT     09/1200Z 34.5N  68.0W    50 KTS
48HR VT     10/0000Z 39.5N  62.5W    50 KTS...EXTRATROPICAL
 
 
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