Storm Summary for Hurricane Sandy
Thursday, October 25, 2012 at 11 AM EDT
Hurricane Sandy is currently a Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale, with
maximum sustained winds of 105 mph (90 kts), moving north at 16 mph. The estimated minimum central
pressure is 964 mb. Hurricane-force winds extend outward up to 30 miles (45 km) from the storm
center. Tropical storm-force winds extend outward up to 140 miles (220 km) from the storm center.
THE SATELLITE PRESENTATION OF SANDY HAS BECOME A LITTLE LESS
IMPRESSIVE AFTER MOVING OVER EASTERN CUBA. THE EYE IS NO LONGER
APPARENT IN IMAGERY OR IN OBSERVATIONS FROM THE AIRCRAFT...AND THE
CDO HAS BECOME SOMEWHAT DISRUPTED ON THE WESTERN SIDE BY
SOUTHWESTERLY FLOW FROM AN UPPER-LEVEL LOW TO THE WEST. HOWEVER...
AIRCRAFT DATA INDICATE THAT THE CIRCULATION ASSOCIATED WITH SANDY
REMAINS QUITE STRONG...WITH A PEAK FLIGHT-LEVEL WIND AT 700 MB OF
126 KT AND A CENTRAL PRESSURE OF 964 MB. DATA FROM THE SFMR AND
DROPSONDES SUGGEST THAT THE WINDS FROM FLIGHT LEVEL ARE NOT
CURRENTLY MIXING DOWN TO THE SURFACE AT THE TYPICAL RATIO...SO A
BLEND OF THE DATA SUPPORT MAINTAINING AN INTENSITY OF 90 KT FOR THIS
ADVISORY. A CONTINUED INCREASE IN SHEAR AND INTERACTION WITH THE
UPPER-LEVEL LOW SHOULD RESULT IN GRADUAL WEAKENING DURING THE NEXT
COUPLE OF DAYS. HOWEVER...DURING THIS TIME THE OUTER WIND FIELD OF
SANDY IS EXPECTED TO EXPAND...AND SANDY IS FORECAST TO BE A LARGE
CYCLONE AT OR NEAR HURRICANE INTENSITY THROUGH THE END OF THE
FORECAST PERIOD.
THE INITIAL MOTION ESTIMATE IS 360/14...AFTER A BIT OF A JOG TO THE
RIGHT EARLIER THIS MORNING. THE REASONING FOR THE SHORT-TERM
PORTION OF THE TRACK FORECAST REMAINS UNCHANGED. SANDY SHOULD MOVE
NORTHWARD TODAY AND SLOW DOWN AS IT TURNS NORTH-NORTHWESTWARD ON
FRIDAY WHEN IT INTERACTS WITH THE AFOREMENTIONED UPPER-LEVEL LOW.
SANDY SHOULD THEN TURN NORTH-NORTHEASTWARD BY 72 HOURS AHEAD OF A
LONGWAVE TROUGH MOVING THROUGH THE EASTERN UNITED STATES. AFTER
THAT TIME...THE TRACK MODEL GUIDANCE CONTINUES TO TREND TOWARD A
NORTHWESTWARD TURN AS SANDY INTERACTS WITH AN AMPLIFYING SHORTWAVE
TROUGH OVER THE MID-ATLANTIC STATES. HOWEVER...THERE REMAIN
SIGNIFICANT DETAIL DIFFERENCES IN REGARD TO THE TIMING OF THIS
INTERACTION AND WHERE THE NORTHWEST TURN WILL OCCUR. THE ECMWF AND
GFDL MODELS SHOW A QUICKER TURN...BRINGING THE CENTER INLAND BY DAY
5. MUCH OF THE REST OF THE GUIDANCE SUGGESTS A MORE GRADUAL TURN
WITH THE CENTER STILL OFFSHORE AT 120 HOURS. THE NHC FORECAST HAS
BEEN SHIFTED WESTWARD AT DAYS 4 AND 5 AND LIES ABOUT HALFWAY
BETWEEN THE ECMWF AND THE GFS ENSEMBLE MEAN AND CLOSE TO THE ECMWF
ENSEMBLE MEAN. REGARDLESS OF THE EXACT TRACK OF SANDY...IT
IS LIKELY THAT SIGNIFICANT IMPACTS WILL BE FELT OVER PORTIONS OF
THE U.S. EAST COAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK.
NOTE THAT THE TROPICAL CYCLONE WIND SPEED PROBABILITIES ARE NOT
DESIGNED TO HANDLE THE TYPE OF STRUCTURAL CHANGES ANTICIPATED WITH
SANDY DURING THE FORECAST PERIOD. AS A RESULT...THESE PROBABILITIES
WILL UNDERESTIMATE THE ACTUAL RISK OF STRONG WINDS AWAY FROM THE
CENTER OF SANDY.
