Tropical Depression FIFTEEN
ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION FIFTEEN DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT THU SEP 25 2003 AFTER A LONG AND DIFFICULT DEBATE TO DETERMINE THE STRUCTURE OF THE CYCLONE...TROPICAL OR SUBTROPICAL....THE AREA OF DISTURBED WEATHER SOUTHEAST OF BERMUDA IS BEING DESIGNATED AS TROPICAL DEPRESSION FIFTEEN. THERE ARE NO CLEAR CUT SIGNALS AND WE COULD HAVE GONE TROPICAL OR SUBTROPICAL AT THIS TIME. THE CYCLONE IS STILL SOMEWHAT ATTACHED TO A FRONTAL ZONE BUT AT THE SAME TIME...IT HAS ENOUGH CONVECTION NEAR THE CENTER. IN ADDITION...THE LASTEST AMSU DATA SHOW A WEAK WARM CORE AT THE MID TO UPPER-LEVELS SUGGESTING THAT THE CYCLONE IS ON ITS WAY TO BECOME MORE TROPICAL. SLOW STRENGTHENING IS INDICATED BEFORE THE SYSTEM MOVES OVER COOL WATERS AND BECOMES EXTRATROPICAL IN 4 DAYS. THE DEPRESSION APPEARS TO BE MOVING SLOWLY TOWARD THE NORTHEAST. HOWEVER...A DEVELOPING SUBTROPICAL RIDGE TO THE EAST OF THE CYCLONE WILL FORCE THE SYSTEM TO MOVE ON A GENERAL NORTHWARD TRACK FOR THE NEXT 3 TO 4 DAYS. THIS IS CONSISTENT WITH THE GFDL AND THE GFS. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 25/1500Z 29.5N 61.0W 30 KT 12HR VT 26/0000Z 30.5N 61.0W 35 KT 24HR VT 26/1200Z 32.0N 61.0W 45 KT 36HR VT 27/0000Z 33.5N 61.5W 55 KT 48HR VT 27/1200Z 35.0N 62.0W 55 KT 72HR VT 28/1200Z 40.0N 63.2W 55 KT 96HR VT 29/1200Z 46.0N 62.0W 55 KT...EXTRATROPICAL 120HR VT 30/1200Z...ABSORBED NNNN