ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM SUBTROPICAL STORM TWO DISCUSSION NUMBER 1 NATIONAL WEATHER SERVICE MIAMI FL 4 PM EST SAT NOV 24 2001 A NON-TROPICAL LOW IN THE CENTRAL NORTH ATLANTIC APPEARS TO HAVE DEVELOPED A CORE OF STRONG WINDS. THIS IS BASED ON A MESSAGE CONCERNING A SHIP THAT WENT THROUGH A STORM CENTER AT 29.5 NORTH AND 50.5 WEST...LOWEST PRESSURE 989 MB AND "LOTS OF DAMAGE" THE TIME OF THE EVENT OR THE HIGHEST WINDS WERE NOT GIVEN. CURRENTLY THERE IS MODERATE CONVECTION SPIRALING AROUND THE CENTER AS WELL AS GALE FORCE WINDS EXTENDING HUNDREDS OF MILES TO THE NORTH. SO WHAT WE HAVE HERE IS A SMALL TROPICAL-LIKE CENTER EMBEDDED WITHIN A HUGE NON-TROPICAL CYCLONE. THE WINDS ARE STRONG NEAR THE CENTER BASED ON THE SHIP REPORT...BUT ARE ALSO STRONG FOR HUNDREDS OF MILES TO THE NORTH. SO I AM CALLING THE SYSTEM A 50-KNOT SUBTROPICAL STORM...A NON FRONTAL LOW PRESSURE SYSTEM COMPRISING INITIALLY BAROCLINIC CIRCULATIONS OVER SUBTROPICAL WATERS. THE AVIATION MODEL SHOWS THE SYSTEM CAUGHT IN A WEAK STEERING PATTERN AND FORECASTS A SLOW MOSTLY NORTHWESTWARD MOTION FOR THE NEXT 72 HOURS. THE OFFICIAL FORECAST FOLLOWS THIS GUIDANCE. INTENSITY GUIDANCE SUGGESTS LITTLE CHANGE IN STRENGTH FOR THE NEXT 72 HOURS. THE PURPOSE OF THIS ADVISORY PACKAGE IS TO ADVISE SHIPS AT SEA THAT THERE COULD BE STRONG WINDS CONCENTRATED NEAR THE CYCLONE CENTER AS WELL AS EXTENDING FAR TO THE NORTH. I DO NOT KNOW HOW LONG THE CENTRAL FEATURE WILL PERSIST. IF IT IS SHEARED AWAY...AND THE SHIPS MODEL HAS 27 KNOTS OF SHEAR INCREASING TO 32 KNOTS IN 24 HOURS... THEN THESE SUBTROPICAL ADVISORIES WILL BE TERMINATED. FORECASTER LAWRENCE FORECAST POSITIONS AND MAX WINDS INITIAL 24/2100Z 30.5N 49.5W 50 KTS 12HR VT 25/0600Z 31.0N 49.5W 50 KTS 24HR VT 25/1800Z 32.0N 50.0W 50 KTS 36HR VT 26/0600Z 33.0N 50.9W 50 KTS 48HR VT 26/1800Z 33.8N 52.0W 50 KTS 72HR VT 27/1800Z 34.5N 54.0W 50 KTS NNNN