000
WTNT41 KNHC 250844
TCDAT1
 
TROPICAL STORM OPHELIA DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
500 AM AST SUN SEP 25 2011
 
OPHELIA REMAINS STRONGLY SHEARED WITH THE BULK OF THE THUNDERSTORM
ACTIVITY NOW DISPLACED ABOUT 200 N MI TO THE EAST OF THE LOW-LEVEL
CENTER. IF DEEP CONVECTION DOES NOT REDEVELOP NEAR THE CENTER LATER
TODAY...OPHELIA WOULD LACK THE NECESSARY ORGANIZED DEEP CONVECTION
TO BE CONSIDERED A TROPICAL CYCLONE. THE INITIAL INTENSITY IS
LOWERED TO 35 KT...WHICH IS STILL ABOVE THE SATELLITE INTENSITY
ESTIMATES. SOUTHWESTERLY WIND SHEAR OF AT LEAST 20 KT...DUE IN PART
TO AN UPPER-LEVEL LOW TO THE WEST OF OPHELIA...IS EXPECTED TO
PERSIST FOR THE NEXT COUPLE OF DAYS. THIS UNFAVORABLE ATMOSPHERIC
ENVIRONMENT SHOULD PROHIBIT STRENGTHENING DURING THAT TIME. IF
OPHELIA SURVIVES BEYOND A COUPLE OF DAYS...SLIGHT STRENGTHENING IS
POSSIBLE AS SUGGESTED BY THE REGIONAL HURRICANE MODELS.
 
THE TROPICAL STORM HAS BEEN MOVING MORE WESTWARD SINCE IT HAS BECOME
DECOUPLED FROM THE CONVECTION...AND THE LATEST INITIAL MOTION
ESTIMATE IS 280/10. THE FUTURE TRACK OF OPHELIA WILL DEPEND ON ITS
VERTICAL COHERENCY. MOST OF THE MODELS...WHICH SHOW OPHELIA AS A
RELATIVELY DEEP CYCLONE...TURN THE CYCLONE GRADUALLY NORTHWARD
DURING THE NEXT SEVERAL DAYS. THE GFS MODEL...HOWEVER...KEEPS A
SHALLOWER SYSTEM ON A MORE WEST-NORTHWESTWARD PATH. GIVEN THE
CURRENT SATELLITE PRESENTATION OF OPHELIA...THE GFS SOLUTION IS
PREFERRED AND THE OFFICIAL FORECAST HAS BEEN ADJUSTED TOWARD THAT
MODEL AND THE SHALLOW BAM.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  25/0900Z 18.4N  59.5W   35 KT  40 MPH
 12H  25/1800Z 19.1N  60.7W   35 KT  40 MPH
 24H  26/0600Z 19.9N  61.8W   35 KT  40 MPH
 36H  26/1800Z 20.7N  63.0W   35 KT  40 MPH
 48H  27/0600Z 21.4N  64.1W   35 KT  40 MPH
 72H  28/0600Z 22.8N  65.6W   40 KT  45 MPH
 96H  29/0600Z 25.0N  66.5W   45 KT  50 MPH
120H  30/0600Z 27.0N  67.5W   45 KT  50 MPH
 
$$
FORECASTER CANGIALOSI