Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane SANDY


ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
 
HURRICANE SANDY DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182012
1100 AM EDT WED OCT 24 2012
 
DATA FROM THE HURRICANE HUNTER AIRCRAFT INDICATE THAT SANDY HAS
REACHED HURRICANE STRENGTH. THE AIRCRAFT JUST MEASURED A PEAK
700-MB FLIGHT-LEVEL WIND OF 86 KT...AND BLENDING THAT WITH THE PEAK
SFMR WINDS YIELDS AN INITIAL INTENSITY OF 70 KT. THE CENTRAL
PRESSURE HAS ALSO FALLEN TO 973 MB BASED ON DATA FROM THE PLANE.
CONDITIONS APPEAR FAVORABLE FOR ADDITIONAL INTENSIFICATION UNTIL
THE CYCLONE MOVES NEAR OR OVER EASTERN JAMAICA...AND THE OFFICIAL
FORECAST SHOWS SOME STRENGTHENING AT 12 HOURS. AFTER THAT TIME...
ADDITIONAL LAND INTERACTION WITH EASTERN CUBA AND STRUCTURAL
CHANGES DUE TO INTERACTION WITH AN UPPER-LEVEL TROUGH MAKE THE
INTENSITY FORECAST HIGHLY UNCERTAIN. INCREASING SHEAR SHOULD RESULT
IN LESS FAVORABLE CONDITIONS FOR INTENSIFICATION VIA LATENT HEAT
RELEASE...BUT THIS COULD BE COMPENSATED FOR BY BAROCLINIC
PROCESSES. GIVEN THE UNCERTAINTY...THE NHC INTENSITY FORECAST
REMAINS UNCHANGED AT 36 HOURS AND BEYOND...SHOWING SANDY BECOMING A
POWERFUL POST-TROPICAL CYCLONE BY THE END OF THE PERIOD.
 
THE INITIAL MOTION IS 015/11. THE SHORT-TERM TRACK FORECAST
REASONING REMAINS UNCHANGED FOR THE FIRST COUPLE OF DAYS...AS SANDY
SHOULD MOVE GENERALLY NORTHWARD INTO A BREAK IN THE SUBTROPICAL
RIDGE OVER THE BAHAMAS AS IT INTERACTS WITH AN UPPER-LEVEL LOW TO
ITS WEST. LATE IN THE PERIOD...THERE REMAINS CONSIDERABLE SPREAD IN
THE GUIDANCE DUE TO DIFFERENCES IN HOW MUCH SANDY INTERACTS WITH
ANOTHER TROUGH MOVING INTO THE NORTHEASTERN UNITED STATES. THE
ECMWF HAS BEEN CONSISTENT IN SHOWING MORE INTERACTION AND A TRACK
FARTHER WEST...WHILE THE GFS SHOWS SANDY TURNING EAST AND MISSING
THE TROUGH. OVERALL MORE OF THE GUIDANCE HAS BEEN TRENDING TOWARD
SHOWING MORE INTERACTION WITH THE EASTERN U.S. TROUGH LATE IN THE
PERIOD. GIVEN THIS TREND...THE NHC FORECAST HAS BEEN ADJUSTED TO THE
LEFT AT DAYS 4 AND 5...AND LIES ROUGHLY BETWEEN THE ECMWF AND THE
TVCA MULTI-MODEL CONSENSUS. NEEDLESS TO SAY...THE TRACK FORECAST
UNCERTAINTY REMAINS HIGH AT THE END OF THE PERIOD.
 
GIVEN THE LATEST NHC FORECAST...A HURRICANE WATCH HAS BEEN ISSUED
FOR THE CENTRAL AND NORTHWEST BAHAMAS...AND THE TROPICAL STORM
WATCH HAS BEEN EXTENDED NORTHWARD ALONG THE EAST-CENTRAL FLORIDA
COAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 17.1N  76.7W   70 KT  80 MPH
 12H  25/0000Z 19.1N  76.5W   75 KT  85 MPH
 24H  25/1200Z 21.9N  76.4W   65 KT  75 MPH
 36H  26/0000Z 24.4N  76.4W   60 KT  70 MPH
 48H  26/1200Z 26.3N  76.7W   60 KT  70 MPH
 72H  27/1200Z 28.7N  76.0W   60 KT  70 MPH
 96H  28/1200Z 32.0N  73.0W   60 KT  70 MPH
120H  29/1200Z 35.5N  70.0W   60 KT  70 MPH...POST-TROPICAL
 
$$
FORECASTER BRENNAN
 
NNNN