| WTNT33 KNHC 291439 TCPAT3 BULLETIN HURRICANE SANDY ADVISORY NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 AM EDT MON OCT 29 2012 ...SANDY FORECAST TO TURN NORTHWESTWARD SOON... ...EXPECTED TO BRING LIFE-THREATENING STORM SURGE AND COASTAL HURRICANE WINDS PLUS HEAVY APPALACHIAN SNOWS... SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...37.5N 71.5W ABOUT 205 MI...330 KM SE OF ATLANTIC CITY NEW JERSEY ABOUT 260 MI...415 KM SSE OF NEW YORK CITY MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...943 MB...27.85 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... THE BERMUDA WEATHER SERVICE HAS DISCONTINUED THE TROPICAL STORM WARNING FOR BERMUDA. 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 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 1100 AM EDT...1500 UTC...THE CENTER OF HURRICANE SANDY WAS LOCATED NEAR LATITUDE 37.5 NORTH...LONGITUDE 71.5 WEST. SANDY IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 18 MPH...30 KM/H. A TURN TOWARD THE NORTHWEST IS EXPECTED SOON...FOLLOWED BY A TURN TOWARD THE WEST-NORTHWEST TONIGHT. ON THE FORECAST TRACK... THE CENTER OF SANDY IS EXPECTED TO MAKE LANDFALL ALONG OR JUST SOUTH OF THE SOUTHERN NEW JERSEY COAST THIS EVENING OR TONIGHT. REPORTS FROM AN AIR FORCE HURRICANE HUNTER AIRCRAFT INDICATE THAT THE MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 90 MPH...150 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... MAINLY SOUTHWEST OF THE CENTER...AND TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 485 MILES...780 KM. SUSTAINED WINDS TO TROPICAL STORM FORCE ARE OCCURRING FROM LONG ISLAND SOUTHWARD ALONG THE COASTS OF NEW JERSEY...DELAWARE...AND EASTERN VIRGINIA...AND EXTEND AS FAR INLAND AS THE CENTRAL AND SOUTHERN CHESAPEAKE BAY AND DELAWARE BAY. A WEATHERFLOW REPORT INDICATES A SUSTAINED WIND OF 53 MPH...85 KM/H...WITH A GUST TO 63 MPH...102 KM/H...HAS RECENTLY OCCURRED ON LONG ISLAND AT EATONS NECK NEW YORK. THE ESTIMATED MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY RECONNAISSANCE AIRCRAFT WAS 943 MB...27.85 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 TODAY. HURRICANE-FORCE WINDS COULD REACH THE MID-ATLANTIC STATES... INCLUDING NEW YORK CITY AND LONG ISLAND...BY THIS EVENING. 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. SNOWFALL OF 1 TO 2 FEET IS EXPECTED IN THE MOUNTAINS OF SOUTHWESTERN VIRGINIA TO THE KENTUCKY BORDER...WITH 12 TO 18 INCHES OF SNOW EXPECTED 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...200 PM EDT. NEXT COMPLETE ADVISORY...500 PM EDT. $$ FORECASTER STEWART HURRICANE SANDY DISCUSSION NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012 1100 AM EDT MON OCT 29 2012 SANDY IS MAINTAINING A SMALL AREA OF DEEP CONVECTION NEAR THE CENTER...WITH BOTH AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT DATA AND VARIOUS MICROWAVE SATELLITE DATA INDICATING A 20 N MI DIAMETER EYE HAS DEVELOPED SINCE THE PREVIOUS ADVISORY. MAXIMUM 700 MB FLIGHT-LEVEL WINDS HAVE BEEN 94 KT IN THE SOUTHERN QUADRANT...AND SFMR-ADJUSTED SURFACE WINDS OF 80-83 KT HAVE BEEN OBSERVED IN THE SOUTHWESTERN QUADRANT MORE THAN 90 N MI FROM THE CENTER. THE AIRCRAFT DATA ALSO INDICATE THAT THE CENTRAL PRESSURE HAS FALLEN A LITTLE...TO ABOUT 943 MB. BASED ON THE LATEST RECONNAISSANCE DATA...THE INITIAL INTENSITY HAS BEEN INCREASED TO 80 KT. RECONNAISSANCE CENTER FIXES INDICATE THAT SANDY HAS BEEN GRADUALLY TURNING TO THE LEFT AND IS NOW MOVING NORTH-NORTHWESTWARD OR ABOUT 330/16 KT. THE LATEST RECON FIXES HAVE BEEN FALLING ON THE PREVIOUS FORECAST TRACK...AND SO HAVE THE LATEST 12Z NHC FORECAST MODELS. THEREFORE...NO SIGNIFICANT CHANGES TO THE ADVISORY PREVIOUS TRACK OR REASONING ARE REQUIRED. SANDY IS NOW LOCATED NORTH OF THE AXIS OF A STRONG NEGATIVELY TILTED MID-/UPPER-LEVEL TROUGH...AND THE HURRICANE SHOULD TURN NORTHWESTWARD VERY SOON. LANDFALL ALONG OR JUST SOUTH OF THE SOUTHERN NEW JERSEY COAST IS EXPECTED LATE THIS EVENING...AT WHICH TIME A TURN TO THE WEST-NORTHWEST IS EXPECTED. AFTER MOVING INLAND OVER THE MID-ATLANTIC STATES A DECREASE IN FORWARD SPEED IS EXPECTED. BY 48 HOURS...THE POST-TROPICAL CYCLONE IS FORECAST TO MOVE NORTHWARD AND THEN NORTHEASTWARD. THE OFFICIAL NHC FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY TRACK...AND LIES CLOSE TO A BLEND OF THE CONSENSUS MODELS TV15 AND TVCN. SANDY IS CURRENTLY TRAVERSING A NARROW RIDGE OF WARM SSTS AROUND 27C...WHICH ARE ASSOCIATED WITH THE GULF STREAM. THIS EXTRA LOW-LEVEL HEAT INPUT HAS LIKELY CONTRIBUTED TO THE RECENT INCREASE IN CONVECTION AROUND THE EYE. HOWEVER...SANDY WILL BE MOVING OVER THE NORTH WALL OF THE GULFSTREAM WITHIN THE NEXT 3 HOURS...WHICH WILL BRING A HALT TO ANY SIGNIFICANT INNER-CORE CONVECTIVE DEVELOPMENT. HOWEVER...THIS SHOULD HAVE LITTLE IMPACT ON THE OVERALL INTENSITY OR THE SIZE OF THE EXTREMELY LARGE WIND FIELD THAT IS NOW MORE THAN 1000 N MI IN DIAMETER. AT THE MOMENT... HURRICANE FORCE WINDS ARE ONLY OCCURRING IN THE SOUTHWEST QUADRANT...BUT MODEL GUIDANCE SUGGESTS THAT THESE COULD SPREAD INTO THE NORTHERN SEMICIRCLE BEFORE LANDFALL. SURFACE DATA INDICATE THAT WELL-DEFINED WARM AND COLD FRONTS LIE VERY NEAR THE CENTER OF SANDY...AND THE COMBINATION OF COLDER OCEAN WATER AND NEARBY FRONTAL SYSTEMS ARE EXPECTED TO RESULT IN EXTRATROPICAL TRANSITION BEFORE THE CENTER OF THE CYCLONE REACHES 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. 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...ESPECIALLY JUST A FEW HUNDRED FEET ABOVE THE GROUND. 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 29/1500Z 37.5N 71.5W 80 KT 90 MPH 12H 30/0000Z 39.0N 74.0W 80 KT 90 MPH...POST-TROP/EXTRATROP 24H 30/1200Z 39.9N 76.7W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 31/0000Z 40.4N 77.9W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 31/1200Z 41.5N 77.2W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 01/1200Z 44.5N 75.6W 30 KT 35 MPH...POST-TROP/EXTRATROP 96H 02/1200Z 45.9N 72.7W 25 KT 30 MPH...POST-TROP/EXTRATROP 120H 03/1200Z 47.5N 68.5W 20 KT 25 MPH...POST-TROP/EXTRATROP $$ FORECASTER STEWART |