000 WTNT43 KNHC 282056 TCDAT3 HURRICANE SANDY DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 500 PM EDT SUN OCT 28 2012 DATA FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATE NO SIGNIFICANT CHANGE TO THE INTENSITY OF SANDY HAS OCCURRED THIS AFTERNOON...AND THE CENTRAL PRESSURE HAS REMAINED NEARLY STEADY AT 951-952 MB SINCE THE PREVIOUS ADVISORY. PEAK 700 MB FLIGHT-LEVEL WINDS OF 78 KT WERE MEASURED IN THE SOUTHERN QUADRANT...BUT NO SFMR-ADJUSTED SURFACE WINDS OF HURRICANE FORCE WERE DETECTED IN ANY QUADRANT. HOWEVER...GIVEN THE EXTREMELY LARGE WIND FIELD OF SANDY...IT IS POSSIBLE THAT THE AIRCRAFT MISSED SOME OF THE POCKETS OF STRONGER SURFACE WINDS. THEREFORE...THE INITIAL INTENSITY IS BEING MAINTAINED AT 65 KT. THE INITIAL MOTION ESTIMATE IS 050/13 KT. THE LATEST MODEL GUIDANCE HAS COME IN NEARLY ON TOP OF THE PREVIOUS ADVISORY TRACK...SO THERE REMAINS NO SIGNIFICANT CHANGES TO THE FORECAST TRACK OR REASONING. SANDY SHOULD CONTINUE TO INTERACT WITH A STRONG NEGATIVELY TILTED SHORTWAVE TROUGH THAT IS MOVING EAST-SOUTHEASTWARD ACROSS THE TENNESSEE VALLEY...AND WILL REACH THE U.S. EAST COAST IN ABOUT 48 HOURS. AS THE TROUGH CONTINUES TO UNDERCUT SANDY TO ITS SOUTH...THE HURRICANE WILL GRADUALLY LIFT NORTHWARD OVER THE NEXT 24 HOURS... FOLLOWED BY A TURN TO THE NORTHWEST AND WEST-NORTHWEST AFTER THAT RIGHT UP UNTIL LANDFALL OCCURS IN ABOUT 36 HOURS. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY TRACK...ALBEIT SLIGHTLY FASTER AFTER 24 HOURS...AND REMAINS NEAR THE MIDDLE OF THE TIGHTLY PACKED GLOBAL AND REGIONAL MODEL FORECASTS. SATELLITE IMAGERY INDICATES THE VERTICAL SHEAR HAS BEEN DECREASING...AND SOME WEAK OUTFLOW IS NOW APPARENT IN THE NORTHERN SEMICIRCLE. THE SHEAR IS EXPECTED TO CONTINUE TO DECREASE DURING THE NEXT 24 HOURS OR SO...AND AS A RESULT SANDY IS EXPECTED MAINTAIN A SMALL AREA OF CONVECTION NEAR THE CENTER WHILE THE HURRICANE REMAINS OVER SSTS GREATER THAN 25C. IN ABOUT 24 HOURS...THE GLOBAL MODELS SHOW SOME BAROCLINIC DEEPENING AS SANDY BEGINS ITS TURN TOWARD THE COAST. A TRANSITION TO AN EXTRATROPICAL CYCLONE IS EXPECTED AT OR SHORTLY BEFORE LANDFALL. HOWEVER...THIS TRANSITION WILL NOT DIMINISH THE OVERALL IMPACTS OF THIS DANGEROUS WEATHER SYSTEM. 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 28/2100Z 33.4N 71.3W 65 KT 75 MPH 12H 29/0600Z 35.0N 70.6W 65 KT 75 MPH 24H 29/1800Z 37.7N 71.8W 70 KT 80 MPH 36H 30/0600Z 39.5N 74.8W 65 KT 75 MPH...POST-TROPICAL 48H 30/1800Z 40.2N 76.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 31/1800Z 42.7N 76.8W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 01/1800Z 44.7N 75.5W 30 KT 35 MPH...POST-TROP/EXTRATROP 120H 02/1800Z 45.6N 71.4W 25 KT 30 MPH...POST-TROP/EXTRATROP $$ FORECASTER STEWART