000 WTNT43 KNHC 281459 TCDAT3 HURRICANE SANDY DISCUSSION NUMBER 25 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 AM EDT SUN OCT 28 2012 DATA FROM NOAA AND AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT MISSIONS THIS MORNING HAVE REVEALED NO SIGNIFICANT CHANGES TO THE INTENSITY OR OVERALL STRUCTURE OF SANDY...EVEN THOUGH SATELLITE IMAGERY INDICATES A BANDING EYE FEATURE IS TRYING TO FORM AND THE CENTRAL PRESSURE HAS BENE AS LOW AS 951 MB. THE AIRCRAFT DATA... ALONG WITH DATA FROM SHIPS...BUOYS...AND SURFACE OBSERVATION SITES INDICATE...HOWEVER...THAT THE WIND FIELD HAS CONTINUED TO EXPAND. HURRICANE-FORCE WINDS NOW EXTEND OUT TO ABOUT 150 N MI TO THE SOUTHWEST...AND THE 50-KT WIND RADII HAVE ALSO INCREASED TO ABOUT 200 N MI IN THAT SAME QUADRANT. BASED ON THE FLIGHT-LEVEL AND SFMR-ADJUSTED SURFACE WINDS...THE INITIAL INTENSITY IS BEING MAINTAINED AT 65 KT. THERE HAVE BEEN SOME TRACK WOBBLES BUT THE INITIAL MOTION ESTIMATE IS 045/12 KT. THERE REMAINS NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK OR REASONING. SANDY WILL CONTINUE TO INTERACT WITH A STRONG NEGATIVELY TILTED SHORTWAVE TROUGH LOCATED OVER THE TENNESSEE VALLEY THAT WILL CONTINUE TO MOVED EASTWARD TOWARD THE U.S. EAST COAST OVER THE NEXT 48 HOURS. AS THE TROUGH UNDERCUTS SANDY TO ITS SOUTH...THE HURRICANE IS EXPECTED TO LIFT NORTHEASTWARD AND THEN NORTHWARD OVER THE NEXT 24 HOURS...FOLLOWED BY A TURN TO THE NORTHWEST AND POSSIBLY WEST-NORTHWEST UNTIL LANDFALL OCCURS WITHIN 48 HOURS OR SO. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY TRACK AND LIES DOWN THE MIDDLE OF THE TIGHTLY PACKED GLOBAL AND REGIONAL MODEL GUIDANCE. THE VERTICAL SHEAR IS FORECAST TO DECREASE IN THE 12 TO 36-HOUR PERIOD AND SANDY IS EXPECTED MAINTAIN A SMALL AREA OF DEEP CONVECTION NEAR THE CENTER WHILE THE HURRICANE REMAINS OVER SSTS GREATER THAN 25C. AS A RESULT...THERE IS STILL SOME POTENTIAL FOR SANDY TO INTENSIFY SLIGHTLY AS A TROPICAL CYCLONE...ESPECIALLY WHEN IT WILL BE TRAVERSING THE WARM GULFSTREAM TONIGHT. BY 36 HOURS... THE GLOBAL MODELS SHOW SOME DEEPENING OF THE CYCLONE...WHICH IS UNDOUBTEDLY DUE TO STRONG BAROCLINIC FORCING...AND A TRANSITION TO AN EXTRATROPICAL CYCLONE IS EXPECTED PRIOR TO LANDFALL. IT IS IMPORTANT TO NOTE THAT THIS TRANSITION WILL NOT DIMINISH THE OVERALL IMPACTS OF THIS DANGEROUS WEATHER SYSTEM. AFTER LANDFALL... THE GLOBAL MODELS...AND THE OFFICIAL INTENSITY FORECAST...INDICATE RAPID WEAKENING IS EXPECTED. AS NOTED IN PREVIOUS ADVISORIES...TO AVOID A HIGHLY DISRUPTIVE CHANGE FROM TROPICAL TO NON-TROPICAL WARNINGS WHEN SANDY BECOMES POST-TROPICAL...THE WIND HAZARD NORTH OF THE TROPICAL STORM WARNING AREA WILL CONTINUE TO BE CONVEYED THROUGH HIGH WIND WATCHES AND WARNINGS ISSUED BY LOCAL NATIONAL WEATHER SERVICE OFFICES. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 32.5N 72.6W 65 KT 75 MPH 12H 29/0000Z 34.0N 71.3W 65 KT 75 MPH 24H 29/1200Z 36.4N 70.7W 70 KT 80 MPH 36H 30/0000Z 38.7N 72.9W 70 KT 80 MPH 48H 30/1200Z 40.1N 76.3W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 31/1200Z 41.3N 77.2W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 01/1200Z 44.5N 76.8W 30 KT 35 MPH...POST-TROP/EXTRATROP 120H 02/1200Z 46.6N 73.4W 25 KT 30 MPH...POST-TROP/EXTRATROP $$ FORECASTER STEWART