000 WTNT43 KNHC 262034 TCDAT3 TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL132007 500 PM EDT WED SEP 26 2007 THE CYCLONE'S CLOUD PATTERN IS WELL-ORGANIZED WITH DISTINCT BANDING FEATURES OVER THE SOUTHERN SEMICIRCLE AND A FAIRLY SYMMETRIC UPPER-LEVEL OUTFLOW. SATELLITE-BASED INTENSITY ESTIMATES FROM TAFB AND SAB ARE BOTH AT TROPICAL STORM STRENGTH. HOWEVER...LOOKS CAN BE DECEIVING...AND RECENT DATA FROM AN AIR FORCE HURRICANE HUNTER MISSION INDICATE THAT THE SYSTEM IS NOT YET A TROPICAL STORM. THE ADVISORY INTENSITY REMAINS 30 KT...AND THIS MAY BE A GENEROUS ESTIMATE SINCE THE HIGHEST FLIGHT-LEVEL WINDS WERE ONLY 29 KT. GIVEN THE ORGANIZATION OF THE SYSTEM...DECREASING SHEAR...AND VERY WARM WATERS...STRENGTHENING IS LIKELY. THE OFFICIAL WIND SPEED FORECAST IS SIMILAR TO THE SHIPS GUIDANCE...AND COULD BE CONSERVATIVE. AIRCRAFT FIXES INDICATE THAT THE CYCLONE IS MEANDERING OR MAY BE EXECUTING A COUNTERCLOCKWISE LOOP. THE TRACK FORECAST REASONING IS ABOUT THE SAME AS EARLIER TODAY. A MID-TROPOSPHERIC RIDGE IS EXPECTED TO BUILD EASTWARD GRADUALLY FROM NORTHERN MEXICO INTO THE GULF OVER THE NEXT FEW DAYS. THIS SHOULD EVENTUALLY STEER THE TROPICAL CYCLONE IN A GENERALLY WESTWARD DIRECTION TOWARD THE COAST OF MEXICO. HOWEVER THE MODELS ARE NOT IN VERY GOOD AGREMMENT. THE U.K. MET. OFFICE MODEL TRACK IS ON THE NORTH SIDE OF THE GUIDANCE SUITE WITH A WEST-NORTHWESTWARD MOTION ACROSS THE COAST IN ABOUT 66 HOURS. THE HWRF MODEL KEEPS THE SYSTEM MEANDERING OFFSHORE AND WEAKENS IT LATE IN THE FORECAST PERIOD. THE GFDL MODEL SHOWS LANDFALL IN ABOUT 36 HOURS...IN CONTRAST TO THE MUCH SLOWER ECMWF WHICH DOES NOT SHOW THE CYCLONE CROSSING THE COASTLINE UNTIL NEARLY 84 HOURS. THE OFFICIAL FORECAST IS ABOUT IN THE MIDDLE OF THESE VARIOUS OBJECTIVE TRACKS. THE MEANDERING MOTION DELAYS THE ISSUANCE OF A TROPICAL STORM WATCH FOR THE GULF COAST OF MEXICO A LITTLE MORE...BUT THE WATCH COULD BE ISSUED LATER TONIGHT OR EARLY TOMORROW. FORECAST POSITIONS AND MAX WINDS INITIAL 26/2100Z 21.3N 94.5W 30 KT 12HR VT 27/0600Z 21.2N 94.8W 35 KT 24HR VT 27/1800Z 20.9N 95.1W 45 KT 36HR VT 28/0600Z 20.7N 95.6W 50 KT 48HR VT 28/1800Z 20.5N 96.3W 55 KT 72HR VT 29/1800Z 20.2N 97.8W 20 KT...INLAND 96HR VT 30/1800Z...DISSIPATED $$ FORECASTER PASCH