Tropical Storm OPHELIA

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TROPICAL STORM OPHELIA DISCUSSION NUMBER  24
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
1100 AM AST WED SEP 28 2011
 
AN AIR FORCE HURRICANE HUNTER AIRCRAFT FOUND THAT OPHELIA HAS
REGAINED TROPICAL STORM INTENSITY.  MAXIMUM FLIGHT-LEVEL WINDS WERE
52 KT AND THE HIGHEST BELIEVABLE SFMR-OBSERVED SURFACE WINDS WERE
40 TO 45 KT.  BASED ON THESE DATA THE INITIAL WIND SPEED IS SET TO
45 KT.  THE STORM HAS BECOME BETTER ORGANIZED ON SATELLITE IMAGES
WITH A CURVED CONVECTIVE BAND NOW EVIDENT OVER THE EASTERN
SEMICIRCLE.  THE ENVIRONMENT AHEAD OF OPHELIA IS NOT IDEAL FOR
STRENGTHENING AS MODERATE WESTERLY SHEAR IS LIKELY TO PREVAIL OVER
THE SYSTEM DURING THE NEXT FEW DAYS.  HOWEVER...THIS SHEAR IS NOT
EXPECTED TO BE STRONG ENOUGH TO PREVENT SOME STRENGTHENING.  THE
OFFICIAL INTENSITY FORECAST IS VERY CLOSE TO THE MODEL CONSENSUS
THAT INCLUDES THE HURRICANE FORECAST IMPROVEMENT PROJECT GUIDANCE.
 
FIXES FROM THE HURRICANE HUNTERS SHOW THAT THE CENTER HAS BEEN
WOBBLING...BUT THE OVERALL MOTION IS ESTIMATED TO BE NORTH-
NORTHWESTWARD OR 340/03.  THERE IS LITTLE CHANGE TO THE NHC
TRACK FORECAST REASONING OR TO THE FORECAST ITSELF.  OPHELIA SHOULD
MOVE NORTH-NORTHWESTWARD...ALONG THE WESTERN PERIPHERY OF A
SUBTROPICAL RIDGE...TODAY AND TOMORROW.  BY 72 HOURS OR SO...A
LARGE MID-TROPOSPHERIC TROUGH MOVING OFF THE U.S. EAST COAST SHOULD
CAUSE THE TROPICAL CYCLONE TO TURN NORTHWARD.  LATER IN THE
FORECAST PERIOD...OPHELIA IS LIKELY TO ACCELERATE NORTH-
NORTHEASTWARD IN THE FLOW AHEAD OF THE TROUGH.  THE OFFICIAL
TRACK FORECAST IS CLOSE TO THE LATEST MULTI-MODEL CONSENSUS AND A
LITTLE FASTER THAN THE GFS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/1500Z 18.7N  59.9W   45 KT  50 MPH
 12H  29/0000Z 19.5N  60.5W   50 KT  60 MPH
 24H  29/1200Z 20.9N  61.1W   50 KT  60 MPH
 36H  30/0000Z 22.5N  61.8W   55 KT  65 MPH
 48H  30/1200Z 24.2N  62.4W   60 KT  70 MPH
 72H  01/1200Z 28.5N  62.7W   65 KT  75 MPH
 96H  02/1200Z 36.0N  60.0W   70 KT  80 MPH
120H  03/1200Z 45.0N  54.0W   50 KT  60 MPH
 
$$
FORECASTER PASCH
 
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