Subtropical Storm MELISSA

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SUBTROPICAL STORM MELISSA DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142013
500 AM AST WED NOV 20 2013
 
A SMALL AREA OF DEEP CONVECTION HAS BEEN PERSISTING NEAR AND TO THE
NORTH OF THE CENTER OF MELISSA SINCE ABOUT 0400 UTC. THIS SUGGESTS
THAT MELISSA COULD BE NEARING THE EXPECTED TRANSITION FROM A
SUBTROPICAL TO A TROPICAL STORM. NONETHELESS...THE STRENGTH OF THE
CYCLONE HAS NOT CHANGED...BASED ON A SATELLITE INTENSITY ESTIMATE
FROM TAFB AND EARLIER ASCAT DATA. THE ENVIRONMENTAL CONDITIONS ARE
NOT CONDUCIVE FOR STRENGTHENING...AS MELISSA IS EXPECTED TO MOVE
OVER PROGRESSIVELY COLDER WATER AND REMAIN IN AT LEAST MODERATE
SOUTH-SOUTHWESTERLY SHEAR. THEREFORE...THE NHC FORECAST CALLS FOR
LITTLE CHANGE IN INTENSITY DURING THE NEXT FEW DAYS...FOLLOWING THE
GFS AND ECMWF GUIDANCE. POST-TROPICAL TRANSITION IS EXPECTED TO
OCCUR IN 24 TO 36 HOURS...WHEN THE CYCLONE IS FORECAST TO BE OVER
SEA SURFACE TEMPERATURES BELOW 20C.
 
MELISSA IS ACCELERATING TO THE NORTHEAST...AND THE LATEST INITIAL
MOTION ESTIMATE IS 055/20. A CONTINUED FAST NORTHEASTWARD TO
EAST-NORTHEASTWARD MOTION IS EXPECTED DURING THE NEXT COUPLE OF
DAYS WHILE MELISSA REMAINS EMBEDDED IN THE STRONG FLOW TO THE
SOUTHEAST OF A LARGE EXTRATROPICAL CYCLONE.  DISSIPATION IS NOW
PREDICTED TO OCCUR IN 4 DAYS...IN AGREEMENT WITH MOST OF THE GLOBAL
MODEL GUIDANCE.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  20/0900Z 34.8N  50.2W   45 KT  50 MPH
 12H  20/1800Z 36.8N  46.4W   45 KT  50 MPH
 24H  21/0600Z 39.3N  40.2W   45 KT  50 MPH
 36H  21/1800Z 41.4N  34.0W   45 KT  50 MPH...POST-TROPICAL
 48H  22/0600Z 43.0N  28.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  23/0600Z 45.0N  22.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
 96H  24/0600Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI
 
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