HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION FOURTEEN DISCUSSION NUMBER   4
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT TUE OCT 15 2002
 
THERE HAS BEEN LITTLE CHANGE IN THE STRUCTURE OF THE DEPRESSION... 
WHICH REMAINS HIGHLY SHEARED...WITH LITTLE BANDING EVIDENT ON IR 
IMAGERY.  THE LATEST REPORTS FROM THE RECONNAISSANCE AIRCRAFT 
INDICATE THAT THE CENTRAL PRESSURE HAS NOT CAHNGED SIGNIFICANTLY.  
THE HIGHEST WINDS FOUND BY THE AIRCRAFT WERE 35 KT...IN THE 
CONVECTION EAST OF THE CENTER...SO THE DEPRESSION REMAINS A 
DEPRESSION.

REPORTS FROM THE AIRCRAFT INDICATE THAT THE DEPRESSION BEGAN TO MOVE 
BEFORE THE LAST INTERMEDIATE ADVISORY.  THE PRECISE SPEED IS UNKNOWN 
SINCE IT IS NOT CLEAR HOW LONG THE DEPRESSION HAS BEEN MOVING....BUT 
MY BEST ESTIMATE OF THE INITIAL MOTION IS 015/6.  THE DEPRESSION 
WILL SOON BE CAUGHT UP IN THE SOUTHWESTERLY FLOW IN ADVANCE OF A 
MID-LATITUDE TROUGH AND DEVELOPING FRONTAL ZONE.  MODEL GUIDANCE IS 
IN EXCELLENT AGREEMENT ON A NORTHEASTWARD TURN WITHIN 24 HOURS.  THE 
PRIMARY TRACK ISSUE IS THE SPEED.  SINCE THE ENVIRONMENTAL FLOW HAS 
SUBSTANTIAL SHEAR...THE FORWARD SPEED WILL TURN ON HOW MUCH VERTICAL 
COHERENCE THE CYCLONE CAN MAINTAIN.  MOST OF THE GUIDANCE IS 
CONSIDERABLY SLOWER THAN THE PREVIOUS OFFICIAL FORECAST...AND SINCE 
I THINK THAT THE SYSTEM WILL HAVE A LOT OF TROUBLE HOLDING 
TOGETHER...THE NEW OFFICIAL FORECAST IS SLOWER THAN THE PREVIOUS 
ONE.  I HAVE ALSO NUDGED THE TRACK TO THE RIGHT...IN RESPONSE TO A 
SIMILAR TREND IN THE GUIDANCE AND THE BEGINNING OF AN EASTWARD 
COMPONENT IN THE INITIAL MOTION.  IF THIS MOTION TREND IS 
CONFIRMED...IT SHOULD BE POSSIBLE TO DROP THE WATCH FOR SOUTH 
FLORIDA LATER TODAY.

THERE IS SOME OPPORTUNITY FOR STRENGTHENING...EARLY IN THE PERIOD 
DUE TO WARM WATERS...AND LATER FROM BAROCLINIC ENERGY 
SOURCES...ALTHOUGH STRONG SHEAR SHOULD PREVENT VERY MUCH 
DEVELOPMENT...EVEN AFTER THE CYCLONE TURNS NORTHEASTWARD.  
EXTRATROPICAL TRANSITION IS LIKELY IN ABOUT 48 HOURS.
 
FORECASTER FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     15/0900Z 17.9N  82.9W    30 KTS
12HR VT     15/1800Z 19.4N  82.2W    35 KTS
24HR VT     16/0600Z 22.0N  80.0W    40 KTS
36HR VT     16/1800Z 25.0N  77.0W    45 KTS
48HR VT     17/0600Z 29.0N  73.0W    50 KTS...EXTRATROPICAL
72HR VT     18/0600Z 38.0N  65.0W    50 KTS...EXTRATROPICAL
 
 
NNNN