000 WTNT43 KNHC 290248 TCDAT3 HURRICANE SANDY DISCUSSION NUMBER 27 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 PM EDT SUN OCT 28 2012 THE CONVECTION NEAR THE CENTER OF SANDY HAS BECOME A LITTLE BETTER ORGANIZED THIS EVENING...WITH A NOAA HURRICANE HUNTER AIRCRAFT REPORTING A 25-35 MILE WIDE EYE WITH AN OPEN EYEWALL. HOWEVER... THE STRONGEST WINDS IN THE STORM ARE NOT OCCURRING IN THE EYEWALL...AS THE NOAA AND AIR FORCE RESERVE AIRCRAFT FOUND A LARGE AREA OF AT LEAST 60 KT SURFACE WINDS ABOUT 100-120 N MI SOUTHWEST OF THE CENTER. IN ADDITION...THE AIR FORCE PLANE REPORTED 700-MB FLIGHT-LEVEL WINDS OF 102 KT. BASED ON THESE DATA...AND THE LIKELIHOOD THAT THE STRONGEST WINDS WERE NOT SAMPLED...THE INITIAL INTENSITY REMAINS 65 KT. SANDY HAS TURNED A LITTLE TO THE LEFT DURING THE PAST FEW HOURS... WITH THE INITIAL MOTION NOW 035/12. THERE IS LITTLE CHANGE TO THE TRACK GUIDANCE OR THE FORECAST TRACK SINCE THE PREVIOUS ADVISORY... WITH SANDY EXPECTED TO TURN NORTHWARD DURING THE NEXT SEVERAL HOURS AND NORTHWESTWARD ON MONDAY. THE FORECAST TRACK BRINGS THE CENTER NEAR OVER THE COAST OF THE MID-ATLANTIC STATES IN ABOUT 30 HOURS... AND IT SHOULD BE NOTED THAT SOME OF THE GUIDANCE HAS AN EARLIER LANDFALL TIME THAN THE OFFICIAL FORECAST. AFTER LANDFALL...SANDY IS EXPECTED TO MERGE WITH THE DEEP-LAYER BAROCLINIC TROUGH OVER THE EASTERN UNITED STATES AND GRADUALLY TURN NORTHWARD. A TURN TOWARD THE EAST IS LIKELY BY THE END OF THE FORECAST PERIOD IF SANDY SURVIVES THAT LONG. VERTICAL WIND SHEAR HAS DECREASED OVER SANDY...AND THE CENTER IS MOVING OVER A LOCALLY WARMER PATCH OF WATER. THESE CONDITIONS MAY HAVE ALLOWED THE EYEWALL FORMATION...AND THEY COULD LEAD TO SOME STRENGTHENING IN ADDITION TO THAT CAUSED BY BAROCLINIC PROCESSES. HOWEVER...SURFACE AND UPPER-AIR DATA SHOW THAT THE PROCESS OF EXTRATROPICAL TRANSITION IS BEGINNING...WITH THE LOW-LEVEL COLD FRONT NOW INTERACTING WITH THE WEST SIDE OF THE CIRCULATION. THIS TRANSITION IS EXPECTED TO BE COMPLETE WITHIN 24 HOURS...BUT IT WILL NOT DIMINISH THE OVERALL IMPACTS FROM WINDS TO HURRICANE STRENGTH...LIFE-THREATENING STORM SURGE...AND FLOODING RAINS ASSOCIATED WITH THIS DANGEROUS WEATHER SYSTEM. SANDY IS EXPECTED TO WEAKEN AFTER LANDFALL. 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 29/0300Z 34.5N 70.5W 65 KT 75 MPH 12H 29/1200Z 36.4N 70.9W 65 KT 75 MPH 24H 30/0000Z 38.7N 73.2W 70 KT 80 MPH...POST-TROP/EXTRATROP 36H 30/1200Z 39.8N 75.8W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 31/0000Z 40.6N 77.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 01/0000Z 43.5N 77.0W 30 KT 35 MPH...POST-TROP/EXTRATROP 96H 02/0000Z 45.5N 75.0W 25 KT 30 MPH...POST-TROP/EXTRATROP 120H 03/0000Z 46.0N 70.0W 25 KT 30 MPH...POST-TROP/EXTRATROP $$ FORECASTER BEVEN