Tropical Storm OPHELIA

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TROPICAL STORM OPHELIA DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
1100 AM AST WED SEP 21 2011
 
ALTHOUGH OPHELIA APPEARS TO BE LESS ORGANIZED THIS MORNING...WITH
THE LOW-LEVEL CENTER PARTIALLY EXPOSED TO THE SOUTHWEST OF THE DEEP
CONVECTION...A 1200 UTC ASCAT PASS AND AN OBSERVATION FROM SHIP
PBSY INDICATES THAT THE INTENSITY HAS INCREASED TO NEAR 50 KT. 
SINCE THE SATELLITE PRESENTATION IS CURRENTLY NOT SUGGESTIVE OF
STRENGTHENING...IT IS CERTAINLY POSSIBLE THAT THE CYCLONE WAS
STRONGER THAN PREVIOUSLY ESTIMATED.  LATEST ANALYSES FROM UW-CIMSS
SHOW THAT THE STORM IS EXPERIENCING ABOUT 20 KT OF
SOUTH-SOUTHWESTERLY SHEAR.  GLOBAL MODEL GUIDANCE INDICATES THAT THE
SHEAR WILL NOT RELENT OVER THE NEXT SEVERAL DAYS...AND THE OFFICIAL
INTENSITY FORECAST CALLS FOR SLOW WEAKENING OVER THE FORECAST
PERIOD.  THIS IS IN CLOSE AGREEMENT WITH THE LGEM AND SHIPS
PREDICTIONS.  IT SHOULD BE NOTED THAT THE COAMPS-TC MODEL...WHICH
IS PART OF THE HFIP SUITE AND HAS BEEN A GOOD PERFORMER SO FAR THIS
YEAR...SHOWS A FASTER DEMISE OF THE TROPICAL CYCLONE THAN MOST OF
THE OTHER GUIDANCE.

INITIAL MOTION IS A LITTLE FASTER TOWARD THE WEST...OR 270/14.  THE
GENERAL TRACK FORECAST SCENARIO FOR OPHELIA REMAINS THE SAME.  THE
CYCLONE SHOULD MOVE ON A WEST TO WEST-NORTHWESTWARD PATH TO THE
SOUTH OF A SUBTROPICAL HIGH PRESSURE AREA DURING THE NEXT FEW DAYS. 
LATE IN THE FORECAST PERIOD A GRADUAL TURN TO THE RIGHT IS LIKELY
AS OPHELIA...IF IT SURVIVES...NEARS THE SOUTHWESTERN SIDE OF THE
HIGH.  THE OFFICIAL TRACK FORECAST LIES BETWEEN THE PREVIOUS ONE
AND THE MULTI-MODEL CONSENSUS.  IT IS ALSO FAIRLY CLOSE TO THE
RELIABLE GFS GUIDANCE.

THE WIND RADII HAVE BEEN EXPANDED BASED ON THE SCATTEROMETER DATA.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 13.0N  43.6W   50 KT  60 MPH
 12H  22/0000Z 13.3N  45.6W   50 KT  60 MPH
 24H  22/1200Z 13.5N  48.4W   45 KT  50 MPH
 36H  23/0000Z 14.0N  50.8W   45 KT  50 MPH
 48H  23/1200Z 14.7N  53.2W   45 KT  50 MPH
 72H  24/1200Z 16.8N  57.8W   45 KT  50 MPH
 96H  25/1200Z 19.0N  62.0W   40 KT  45 MPH
120H  26/1200Z 21.0N  65.5W   35 KT  40 MPH
 
$$
FORECASTER PASCH
 
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