| http://hurricanes.gov/ HURRICANE SANDY ADVISORY NUMBER 28 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 500 AM EDT MON OCT 29 2012 ...SANDY STRENGTHENS...EXPECTED TO BRING LIFE-THREATENING STORM SURGE...COASTAL HURRICANE WINDS AND HEAVY APPALACHIAN SNOWS... SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...35.9N 70.5W ABOUT 285 MI...460 KM E OF CAPE HATTERAS NORTH CAROLINA ABOUT 385 MI...615 KM SSE OF NEW YORK CITY MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...946 MB...27.94 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... NONE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WARNING IS IN EFFECT FOR... * NORTH OF SURF CITY TO DUCK NORTH CAROLINA * PAMLICO AND ALBEMARLE SOUNDS * BERMUDA IN ADDITION...HURRICANE-FORCE WINDS ARE EXPECTED ALONG PORTIONS OF THE COAST BETWEEN CHINCOTEAGUE VIRGINIA AND CHATHAM MASSACHUSETTS. THIS INCLUDES THE TIDAL POTOMAC FROM COBB ISLAND TO SMITH POINT... THE MIDDLE AND UPPER CHESAPEAKE BAY...DELAWARE BAY...AND THE COASTS OF THE NORTHERN DELMARVA PENINSULA...NEW JERSEY...THE NEW YORK CITY AREA...LONG ISLAND...CONNECTICUT...AND RHODE ISLAND. TROPICAL-STORM-FORCE WINDS ARE EXPECTED NORTH OF CHATHAM TO MERRIMACK RIVER MASSACHUSETTS...THE LOWER CHESAPEAKE BAY...AND SOUTH OF CHINCOTEAGUE TO DUCK NORTH CAROLINA...THE NORTHERN ENDPOINT OF THE TROPICAL STORM WARNING. OTHER COASTAL AND INLAND WATCHES AND WARNINGS ARE IN EFFECT FOR THESE AREAS. PLEASE SEE STATEMENTS FROM LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICES. FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 500 AM EDT...0900 UTC...THE CENTER OF HURRICANE SANDY WAS LOCATED NEAR LATITUDE 35.9 NORTH...LONGITUDE 70.5 WEST. SANDY IS MOVING TOWARD THE NORTH NEAR 15 MPH...24 KM/H. A TURN TOWARD THE NORTHWEST IS EXPECTED TODAY...FOLLOWED BY A TURN TOWARD THE WEST-NORTHWEST TONIGHT. ON THE FORECAST TRACK...THE CENTER OF SANDY WILL MOVE OVER THE COAST OF THE MID-ATLANTIC STATES THIS EVENING OR TONIGHT. REPORTS FROM AN AIR FORCE HURRICANE HUNTER AIRCRAFT INDICATE THAT THE MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 85 MPH...140 KM/H...WITH HIGHER GUSTS. SANDY IS EXPECTED TO TRANSITION INTO A FRONTAL OR WINTERTIME LOW PRESSURE SYSTEM PRIOR TO LANDFALL. HOWEVER...THIS TRANSITION WILL NOT BE ACCOMPANIED BY A WEAKENING OF THE SYSTEM...AND IN FACT...A LITTLE STRENGTHENING IS POSSIBLE DURING THIS PROCESS. SANDY IS EXPECTED TO WEAKEN AFTER MOVING INLAND. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 175 MILES...280 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 485 MILES...780 KM. NOAA DATA BUOY 41001 LOCATED EAST OF CAPE HATTERAS REPORTED SUSTAINED WINDS OF 64 MPH WITH A GUST OF 85 MPH. A WEATHERFLOW STATION IN THIRD ISLAND VIRGINIA REPORTED SUSTAINED WINDS OF 51 MPH WITH A GUST OF 59 MPH. A WEATHERFLOW STATION IN LEWES DELAWARE REPORTED SUSTAINED WINDS OF 43 MPH WITH A GUST OF 49 MPH. THE MINIMUM CENTRAL PRESSURE ESTIMATED FROM HURRICANE HUNTER AIRCRAFT DATA IS 946 MB...27.94 INCHES. HAZARDS AFFECTING LAND ---------------------- WIND...TROPICAL STORM CONDITIONS...OR GALE FORCE WINDS...ARE ALREADY OCCURRING OVER PORTIONS OF THE MID-ATLANTIC STATES FROM NORTH CAROLINA NORTHWARD TO LONG ISLAND. GALE FORCE WINDS ARE EXPECTED TO CONTINUE TO SPREAD OVER OTHER PORTIONS OF THE MID-ATLANTIC COAST...NEW YORK CITY...AND SOUTHERN NEW ENGLAND LATER THIS MORNING. WINDS OF HURRICANE FORCE COULD REACH THE MID-ATLANTIC STATES...INCLUDING NEW YORK CITY AND LONG ISLAND...LATER TODAY. WINDS AFFECTING THE UPPER FLOORS OF HIGH-RISE BUILDINGS WILL BE SIGNIFICANTLY STRONGER THAN THOSE NEAR GROUND LEVEL. STORM SURGE...THE COMBINATION OF AN EXTREMELY DANGEROUS STORM SURGE AND THE TIDE WILL CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE... NC NORTH OF SURF CITY INCLUDING PAMLICO/ALBEMARLE SOUNDS...4 TO 6 FT SE VA AND DELMARVA INCLUDING LOWER CHESAPEAKE BAY...2 TO 4 FT UPPER AND MIDDLE CHESAPEAKE BAY...1 TO 3 FT LONG ISLAND SOUND...RARITAN BAY...AND NEW YORK HARBOR...6 TO 11 FT ELSEWHERE FROM OCEAN CITY MD TO THE CT/RI BORDER...4 TO 8 FT CT/RI BORDER TO THE SOUTH SHORE OF CAPE COD INCLUDING BUZZARDS BAY AND NARRAGANSETT BAY...3 TO 6 FT CAPE COD TO THE MA/NH BORDER INCLUDING CAPE COD BAY...2 TO 4 FT MA/NH BORDER TO THE U.S./CANADA BORDER...1 TO 3 FT SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE TIMING OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER SHORT DISTANCES. GIVEN THE LARGE WIND FIELD ASSOCIATED WITH SANDY...ELEVATED WATER LEVELS COULD SPAN MULTIPLE TIDE CYCLES RESULTING IN REPEATED AND EXTENDED PERIODS OF COASTAL AND BAYSIDE FLOODING. IN ADDITION... ELEVATED WATERS COULD OCCUR FAR REMOVED FROM THE CENTER OF SANDY. FURTHERMORE...THESE CONDITIONS WILL OCCUR REGARDLESS OF WHETHER SANDY IS A TROPICAL OR POST-TROPICAL CYCLONE. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE SEE PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE. RAINFALL...RAINFALL TOTALS OF 3 TO 6 INCHES ARE EXPECTED OVER FAR NORTHEASTERN NORTH CAROLINA WITH ISOLATED MAXIMUM TOTALS OF 8 INCHES POSSIBLE. RAINFALL AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED OVER PORTIONS OF THE MID ATLANTIC STATES...INCLUDING THE DELMARVA PENINSULA...WITH ISOLATED MAXIMUM AMOUNTS OF 12 INCHES POSSIBLE. RAINFALL AMOUNTS OF 1 TO 3 INCHES WITH ISOLATED MAXIMUM AMOUNTS OF 5 INCHES ARE POSSIBLE FROM THE SOUTHERN TIER OF NEW YORK STATE NORTHEASTWARD THROUGH NEW ENGLAND. SNOWFALL..SNOW ACCUMULATIONS OF 2 TO 3 FEET ARE EXPECTED IN THE MOUNTAINS OF WEST VIRGINIA WITH LOCALLY HIGHER TOTALS TODAY THROUGH WEDNESDAY. 1 TO 2 FEET OF SNOW IS EXPECTED IN THE MOUNTAINS OF SOUTHWESTERN VIRGINIA TO THE KENTUCKY BORDER...WITH 12 TO 18 INCHES OF SNOW IN THE MOUNTAINS NEAR THE NORTH CAROLINA/TENNESSEE BORDER AND IN THE MOUNTAINS OF WESTERN MARYLAND. SURF...DANGEROUS SURF CONDITIONS WILL CONTINUE FROM FLORIDA THROUGH NEW ENGLAND FOR THE NEXT COUPLE OF DAYS. NEXT ADVISORY ------------- NEXT INTERMEDIATE ADVISORY...800 AM EDT. NEXT COMPLETE ADVISORY...1100 AM EDT. $$ FORECASTER PASCH/CANGIALOSI HURRICANE SANDY DISCUSSION NUMBER 28 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 500 AM EDT MON OCT 29 2012 SANDY CONTINUES TO MAINTAIN AN AREA OF DEEP CONVECTION NEAR THE CENTER...WITH AN EYE OCCASIONALLY VISIBLE ON SATELLITE IMAGERY. ALTHOUGH THE SATELLITE PRESENTATION OF THE SYSTEM IS NOT VERY IMPRESSIVE...SFMR MEASUREMENTS...FLIGHT-LEVEL WINDS...AND DROPSONDE DATA FROM THE AIR FORCE HURRICANE HUNTERS INDICATE THAT THE WINDS HAVE INCREASED TO NEAR 75 KT. SINCE THE HURRICANE WILL TRAVERSE THE GULF STREAM THIS MORNING...AND THE SHEAR IS NOT TOO STRONG AT THIS TIME...SOME MORE STRENGTHENING AS A TROPICAL CYCLONE IS POSSIBLE IN THE NEXT FEW HOURS. HOWEVER...THE MAIN MECHANISM FOR INTENSIFICATION LATER TODAY SHOULD BE BAROCLINIC FORCING. THE OFFICIAL WIND SPEED FORECAST IS CLOSE TO THE LATEST GFS PREDICTION AS THAT MODEL SHOULD BE ABLE TO HANDLE THE EVOLUTION OF THIS TYPE OF SYSTEM FAIRLY WELL. SURFACE DATA INDICATE THAT A WELL-MARKED WARM AND COLD FRONT LIE NOT FAR TO THE NORTH AND WEST OF THE CENTER OF SANDY. AS THE CIRCULATION INTERACTS WITH THESE FRONTS...THE CYCLONE SHOULD BECOME EXTRATROPICAL LATER TODAY. EXTRATROPICAL TRANSITION IS EXPECTED TO BE COMPLETE BEFORE THE CENTER CROSSES THE COAST. HOWEVER...THIS TRANSFORMATION WILL NOT DIMINISH THE OVERALL IMPACTS FROM WINDS TO HURRICANE STRENGTH...LIFE-THREATENING STORM SURGE...AND FLOODING RAINS ASSOCIATED WITH THIS DANGEROUS WEATHER SYSTEM. BASED ON THE GLOBAL MODELS...THE CYCLONE SHOULD WEAKEN FAIRLY RAPIDLY AFTER LANDFALL. CENTER FIXES INDICATE THAT SANDY IS NOW MOVING NORTHWARD OR ABOUT 360/13...AS IT BEGINS TO ROTATE AROUND A MID- TO UPPER-LEVEL CYCLONE OVER THE SOUTHEASTERN UNITED STATES. AS IT MOVES BETWEEN THE CYCLONE AND A HIGHLY ANOMALOUS MID-TROPOSPHERIC RIDGE NEAR ATLANTIC CANADA...SANDY SHOULD TURN NORTHWESTWARD AND WEST-NORTHWESTWARD WITH SOME FURTHER INCREASE IN FORWARD SPEED. THIS TRACK SHOULD RESULT IN THE CENTER MAKING LANDFALL IN THE MID-ATLANTIC STATES THIS EVENING OR TONIGHT. AFTER LANDFALL...THE DYNAMICAL GUIDANCE SHOWS A SIGNIFICANT SLOWING OF FORWARD SPEED AS THE SYSTEM MERGES WITH THE MID- TO UPPER-LEVEL CYCLONE. THE OFFICIAL TRACK FORECAST FOR THIS PACKAGE IS A BIT FASTER THAN THE PREVIOUS ONE...AND CLOSE TO THE GFS AND ECMWF SOLUTIONS. INTERESTS ARE REMINDED NOT TO FOCUS ON THE CENTER OR THE EXACT FORECAST TRACK OF THIS SYSTEM...SINCE STRONG WINDS COVER AN AREA SEVERAL HUNDRED MILES ACROSS...AND THE HIGHEST WINDS WILL NOT NECESSARILY BE NEAR THE CENTER. 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 29/0900Z 35.9N 70.5W 75 KT 85 MPH 12H 29/1800Z 37.8N 72.0W 80 KT 90 MPH 24H 30/0600Z 39.5N 75.5W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 30/1800Z 40.0N 77.3W 50 KT 60 MPH...POST-TROP/EXTRATROP 48H 31/0600Z 40.5N 77.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 01/0600Z 44.0N 76.5W 30 KT 35 MPH...POST-TROP/EXTRATROP 96H 02/0600Z 45.5N 74.0W 25 KT 30 MPH...POST-TROP/EXTRATROP 120H 03/0600Z 46.5N 70.0W 20 KT 25 MPH...POST-TROP/EXTRATROP $$ FORECASTER PASCH/CANGIALOSI |