|
Show Selection: |
| #35899 (Received by flhurricane at: 10:34 PM 27.Jul.2005) TCDAT1 TROPICAL STORM FRANKLIN DISCUSSION NUMBER 27 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT WED JUL 27 2005 WHILE FRANKLIN CONTINUES TO GENERATE COLD CONVECTIVE TOPS...COLDER THAN -70C...A 0055Z SSM/I OVERPASS INDICATES THAT NO WRAPPING OF THE CONVECTION HAS OCCURRED SINCE THIS AFTERNOON. INDEED...THE THE MICROWAVE DATA SHOWS THE CENTER IS AGAIN EXPOSED TO THE NORTH OF THE MAIN CONVECTION...ALTHOUGH UNDER THE CIRRUS OUTFLOW. WHILE THE REASON FOR THIS IS NOT CLEAR...IT SUGGESTS THAT FRANKLIN IS NO STRONGER THAN IT WAS 6 HR AGO. THE INITIAL INTENSITY REMAINS 45 KT IN AGREEMENT WITH SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 360/5...WITH THE MICROWAVE DATA SUGGESTING FRANKLING MIGHT BE MOVING A LITTLE FASTER. THE TRACK FORECAST IS STRAIGHTFORWARD. FRANKLIN IS BETWEEN A BUILDING DEEP-LAYER RIDGE OVER THE NORTH CENTRAL ATLANTIC AND A MID/YUPPER-LEVEL TROUGH AND ASSOCIATED COLD FRONT OVER THE NORTHEASTERN UNITED STATES. THIS COMBINATION SHOULD GRADUALLY TURN FRANKLIN NORTHEASTWARD IN THE NEXT 12-24 HR...WITH GRADUAL ACCELERATION TOWARD THE NORTHEAST THEREAFTER. ALL TRACK GUIDANCE AGREES WITH THIS SCENARIO...AND THE OFFICIAL FORECAST IS SIMILAR TO...BUT SLIGHTLY LEFT OF...THE PREVIOUS TRACK. VERTICAL SHEAR IS DECREASING OVER FRANKLIN AS THE UPPER-LEVEL FLOW BECOMES GENERALLY SOUTHERLY OVER THE STORM. THIS ALLOWS A WINDOW OF OPPORTUNITY FOR FRANKLIN TO STRENGTHEN BEFORE THE APPROACHING TROUGH INCREASES THE SHEAR...AND THE STORM MOVES NORTH OF THE GULF STREAM. BOTH OF THESE SHOULD OCCUR IN 24-36 HR. THE INTENSITY FORECAST CALLS FOR STRENGTHENING TO 55 KT IN 24 HR...FOLLOWED BY WEAKENING AS FRANKLIN MERGES WITH THE COLD FRONT AND BECOMES EXTRATROPICAL. IT SHOULD BE NOTED THAT 55 KT IS HIGHER THAN EITHER THE SHIPS OR THE GFDL MODELS ARE FORECASTING. AFTER EXTRATROPICAL TRANSITION...FRANKLIN WILL LIKELY BE ABSORBED BY THE FRONT IN 72-96 HR. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 28/0300Z 34.3N 69.4W 45 KT 12HR VT 28/1200Z 35.5N 69.0W 50 KT 24HR VT 29/0000Z 37.3N 67.1W 55 KT 36HR VT 29/1200Z 39.3N 64.4W 55 KT 48HR VT 30/0000Z 41.8N 60.3W 45 KT...BECOMING EXTRATROPICAL 72HR VT 31/0000Z 46.0N 51.0W 30 KT...EXTRATROPICAL 96HR VT 01/0000Z...ABSORBED BY FRONTAL SYSTEM |
