000
WTNT41 KNHC 222033
TCDAT1
 
TROPICAL STORM OPHELIA DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
500 PM AST THU SEP 22 2011
 
STRONG SOUTHWESTERLY SHEAR CONTINUES TO AFFECT OPHELIA...AND MOST OF
THE DEEP CONVECTION IS DISPLACED WELL TO THE NORTHEAST AND EAST OF
THE CENTER.  THE LOW-LEVEL CENTER IS PERHAPS A LITTLE BETTER
DEFINED ON VISIBLE SATELLITE IMAGES THAN IT WAS EARLIER TODAY...
HOWEVER IT IS STILL NOT VERY OBVIOUS.  THE STORM IS QUITE
DISORGANIZED...AND SATELLITE INTENSITY ESTIMATES ONLY SUPPORT A
LOW-END TROPICAL STORM.  HOWEVER...AN ASCAT PASS FROM SEVERAL HOURS
AGO SUGGESTED THAT THE SYSTEM HAD NOT WEAKENED...SO THE INTENSITY
WILL BE HELD AT 55 KT FOR THE TIME BEING.  GLOBAL MODELS INDICATE
THAT OPHELIA WILL CONTINUE TO EXPERIENCE SHEAR ASSOCIATED WITH THE
FLOW ON THE SOUTHEAST SIDE OF AN UPPER-LEVEL CYCLONE CENTERED TO
THE NORTH OF THE GREATER ANTILLES OVER THE NEXT FEW DAYS. 
THEREFORE SOME WEAKENING IS LIKELY OVER THE NEXT 72 HOURS OR SO. 
BY THE END OF THE PERIOD...THE GLOBAL MODELS SUGGEST SOME LESSENING
OF THE SHEAR AS OPHELIA NEARS THE SUBTROPICS...SO RESTRENGTHENING
COULD OCCUR IN 4 TO 5 DAYS...IF THE SYSTEM SURVIVES THAT LONG.  THE
OFFICIAL WIND SPEED FORECAST IS VERY CLOSE TO THE LATEST
STATISTICAL-DYNAMICAL LGEM GUIDANCE.

THE MOTION REMAINS ABOUT THE SAME...280/11...AS OPHELIA CONTINUES TO
BE STEERED BY THE FLOW ON THE SOUTHERN SIDE OF A SUBTROPICAL HIGH
PRESSURE AREA.  A GRADUAL TURN TOWARD THE WEST-NORTHWEST AND
NORTHWEST IS EXPECTED AS THE STORM APPROACHES THE SOUTHWESTERN
PERIPHERY OF THE HIGH LATER IN THE FORECAST PERIOD.  THE OFFICIAL
TRACK FORECAST IS...AGAIN...SHIFTED A LITTLE TOWARD THE NORTH IN
COMPARISON TO THE PREVIOUS ONE.  THIS IS STILL ON THE SOUTHERN SIDE
OF THE MODEL GUIDANCE SUITE.

FORECAST POSITIONS AND MAX WINDS
 
INIT  22/2100Z 13.8N  48.9W   55 KT  65 MPH
 12H  23/0600Z 14.5N  50.7W   50 KT  60 MPH
 24H  23/1800Z 15.7N  53.0W   50 KT  60 MPH
 36H  24/0600Z 17.1N  55.3W   50 KT  60 MPH
 48H  24/1800Z 18.5N  57.3W   45 KT  50 MPH
 72H  25/1800Z 21.5N  61.0W   45 KT  50 MPH
 96H  26/1800Z 23.5N  63.5W   45 KT  50 MPH
120H  27/1800Z 25.5N  65.0W   50 KT  60 MPH
 
$$
FORECASTER PASCH