ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL STORM FELIX DISCUSSION NUMBER 13 NATIONAL WEATHER SERVICE MIAMI FL 11 PM EDT TUE SEP 11 2001 WITH ONLY INFRARED IMAGES...IT IS DIFFICULT TO KNOW WHERE THE LOW LEVEL CENTER IS. USING DEAD RECKONING AND SOME GUIDANCE FROM MICROWAVE DATA...THE INITIAL MOTION ESTIMATE IS 335/09...THE SAME AS THE PREVIOUS ADVISORY. THE 00Z AVIATION MODEL 500 MB FORECAST SHOWS THE STORM MOVING AROUND THE WESTERN PERIPHERY OF A HIGH PRESSURE RIDGE AND THEN BEGINNING TO RECURVE EASTWARD TO THE SOUTH OF A STATIONARY CUTOFF LOW IN THE CENTRAL NORTH ATLANTIC. ALL GUIDANCE AGREES ON THIS SCENARIO AND THE OFFICIAL FORECAST FOLLOWS THIS GUIDANCE. THERE IS CURRENTLY A CDO-TYPE FEATURE FORMING AND THE FORECAST IS FOR MODEST STRENGTHENING UNDER WHAT MAY BE SOME FAIRLY STRONG SHEAR...15 TO 25 KNOTS DURING THE NEXT 72 HOURS ACCORDING TO THE SHIPS DIAGNOSIS OF THE AVIATION MODEL. THE GFDL IS MORE AGGRESSIVE WITH A FORECAST OF 100 KNOTS IN 72 HOURS. FORECASTER LAWRENCE FORECAST POSITIONS AND MAX WINDS INITIAL 12/0300Z 20.7N 48.6W 35 KTS 12HR VT 12/1200Z 22.1N 49.2W 40 KTS 24HR VT 13/0000Z 23.8N 49.8W 50 KTS 36HR VT 13/1200Z 25.6N 50.0W 60 KTS 48HR VT 14/0000Z 27.3N 49.4W 65 KTS 72HR VT 15/0000Z 30.0N 45.5W 65 KTS NNNN