000 WTNT41 KNHC 092056 TCDAT1 TROPICAL STORM IDA DISCUSSION NUMBER 24 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009 300 PM CST MON NOV 09 2009 WITH ONE INTERESTING EXCEPTION...THE LATEST REPORTS FROM AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT INDICATE THAT IDA REMAINS JUST BELOW HURRICANE STRENGTH. A CONVECTIVE BURST THAT BEGAN A FEW HOURS AGO HAS TEMPORARILY HALTED THE WEAKENING TREND. PEAK 850 MB FLIGHT-LEVEL WINDS OF 75 KT AND PEAK SFMR WINDS OF 58 KT SUPPORT MAINTAINING THE ADVISORY INTENSITY AT 60 KT. ON THE MOST RECENT OUTBOUND PASS...HOWEVER...THE SFMR DID REPORT A VERY SMALL AREA OF 70-75 KT SURFACE WINDS SOUTHWEST OF THE CENTER JUST DOWNWIND OF THE CONVECTIVE BURST. GIVEN THAT THE CONCURRENT FLIGHT-LEVEL WINDS WERE ONLY 45 TO 55 KT...THIS APPEARS TO BE A LOCAL CONVECTIVE-SCALE PEAK UNREPRESENTATIVE OF THE CIRCULATION. SSTS BELOW THE CENTER ARE NOW ABOUT 26C...AND GET PROGRESSIVELY COOLER ALONG THE PROJECTED TRACK. VERTICAL WIND SHEAR WILL ALSO BE INCREASING OVER THE NEXT 12 HOURS OR SO. THE 12Z GLOBAL MODELS STILL DO NOT SHOW MUCH IN THE WAY OF BAROCLINIC RE-INTENSIFICATION PRIOR TO LANDFALL...AND SO A RESUMPTION OF THE EARLIER WEAKENING TREND IS EXPECTED TO COMMENCE SOON. IDA IS NOW MOVING NORTHWARD...355/16. THE DYNAMICAL GUIDANCE INDICATES THAT THE FORWARD MOTION SHOULD SLOW APPRECIABLY OVER THE NEXT 12 HOURS...BUT IF THE CONVECTION PERSISTS MUCH LONGER IDA WILL LIKELY MOVE ON SHORE SOONER THAN FORECAST. MY OFFICIAL 12 HOUR FORECAST POINT IS ALREADY AHEAD OF MOST OF THE GUIDANCE. THE REMAINDER OF THE FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY TRACK...AND CALLS FOR IDA TO TURN EASTWARD AFTER LANDFALL AS IT BECOMES EMBEDDED WITHIN A MID-LATITUDE TROUGH MOVING EASTWARD FROM THE WESTERN GULF. STRONG WINDS COVER A LARGE AREA OF THE GULF OF MEXICO AND RAINBANDS ARE ALREADY MOVING ONSHORE WELL AHEAD OF THE CENTER. GIVEN THE CURRENT MOTION AND CONVECTIVE VIGOR...IDA SHOULD MAINTAIN TROPICAL CHARACTERISTICS THROUGH LANDFALL. FORECAST POSITIONS AND MAX WINDS INITIAL 09/2100Z 28.4N 88.5W 60 KT 12HR VT 10/0600Z 30.2N 88.1W 50 KT 24HR VT 10/1800Z 31.0N 87.1W 40 KT...INLAND 36HR VT 11/0600Z 31.0N 85.5W 30 KT...EXTRATROPICAL 48HR VT 11/1800Z 30.0N 83.5W 25 KT...EXTRATROPICAL 72HR VT 12/1800Z...DISSIPATED $$ FORECASTER FRANKLIN