000 WTNT43 KNHC 250302 TCDAT3 HURRICANE SANDY DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 PM EDT WED OCT 24 2012 CUBAN RADAR DATA AND REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THAT SANDY IS BECOMING BETTER ORGANIZED THIS EVENING. THE CENTRAL PRESSURE HAS FALLEN RAPIDLY TO 954 MB... AND A 20-25 N MI WIDE EYE HAS DEVELOPED. THE AIRCRAFT REPORTED 700-MB FLIGHT-LEVEL WINDS OF 102 KT AND BIAS-CORRECTED SFMR SURFACE ESTIMATES OF 75-80 KT. THE INITIAL INTENSITY OF 80 KT IS BASED ON A BLEND OF THESE DATA...AND THIS COULD BE CONSERVATIVE. IT SHOULD BE NOTED THAT SUBJECTIVE SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB...ALONG WITH OBJECTIVE INTENSITY ESTIMATES FROM CIMSS...ARE AT OR ABOVE 100 KT. THIS SUGGESTS THAT SANDY IS LIKELY TO STRENGTHEN FURTHER BEFORE LANDFALL IN CUBA IN A FEW HOURS. THE INITIAL MOTION IS 010/11. THE HURRICANE IS CURRENTLY BETWEEN A MID/UPPER-LEVEL LOW OVER THE NORTHWESTERN CARIBBEAN AND A MID/UPPER-LEVEL RIDGE OVER THE EASTERN CARIBBEAN. THE DYNAMICAL MODELS FORECAST SANDY TO MOVE AROUND AND EVENTUALLY MERGE WITH THE LOW...WHICH SHOULD PRODUCE A NORTHWARD MOTION FOR 24 HR OR SO FOLLOWED BY A NORTH-NORTHWESTWARD TURN. FROM 48-96 HR...A DEEP-LAYER TROUGH MOVING INTO THE EASTERN UNITED STATES SHOULD STEER THE MERGED SYSTEM GENERALLY NORTHEASTWARD. THE GUIDANCE BECOMES DIVERGENT AFTER 96 HR...WITH THE ECMWF/GFDL/NOGAPS TURNING THE CYCLONE NORTHWESTWARD...AND THE GFS/HWRF SHOWING A NORTHEASTWARD MOTION. OVERALL...THE GUIDANCE ENVELOPE HAS SHIFTED EASTWARD SINCE THE PREVIOUS ADVISORY. HOWEVER...THIS IS IN PART DUE TO A LARGE CHANGE IN THE GFS FORECAST AFTER 72 HR. THUS...THE NEW FORECAST WILL SHIFTED ONLY A LITTLE TO THE EAST DURING THIS TIME...AND IT LIES TO THE WEST OF THE CONSENSUS MODELS. HOWEVER... IT REMAINS EAST OF THE ECMWF/NOGAPS/GFDL MODELS. GIVEN THE CURRENT INTENSIFICATION...THE NEW INTENSITY FORECAST NOW CALLS FOR SANDY TO REMAIN A HURRICANE WHILE CROSSING CUBA. WHEN THE CENTER EMERGES NORTH OF CUBA...IT IS FORECAST TO INTERACT WITH AN UPPER-LEVEL TROUGH THAT WILL PROVIDE STRONG UPPER-LEVEL DIVERGENCE AND BAROCLINIC ENERGY. WHILE THIS WILL ALLOW SANDY TO STAY AT OR NEAR HURRICANE STRENGTH...IT IS LIKELY THAT THE WIND FIELD WILL SPREAD OUT AND THAT THE CYCLONE WILL LOSE SOME OF ITS TROPICAL CHARACTER IN THE PROCESS. ALL OF THE GLOBAL MODEL GUIDANCE AGREES WITH THIS SCENARIO...AND THE NEW INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS FORECAST AFTER 24 HR. THE FORECAST WILL STILL CALL FOR SANDY TO BECOME POST-TROPICAL BY 120 HR...ALTHOUGH THIS REMAINS LOW CONFIDENCE. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 19.4N 76.3W 80 KT 90 MPH 12H 25/1200Z 21.6N 76.1W 70 KT 80 MPH 24H 26/0000Z 24.4N 76.2W 70 KT 80 MPH 36H 26/1200Z 26.3N 76.7W 65 KT 75 MPH 48H 27/0000Z 27.6N 77.2W 65 KT 75 MPH 72H 28/0000Z 30.5N 74.5W 60 KT 70 MPH 96H 29/0000Z 33.5N 71.5W 60 KT 70 MPH 120H 30/0000Z 37.0N 70.0W 60 KT 70 MPH...POST-TROPICAL $$ FORECASTER BEVEN