000
WTNT44 KNHC 211449
TCDAT4
 
TROPICAL STORM MELISSA DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142013
1100 AM AST THU NOV 21 2013
 
MELISSA REMAINS A TROPICAL CYCLONE THIS MORNING...AS SATELLITE
PICTURES SHOW A BROKEN BAND OF CONVECTION OVER THE SOUTHEASTERN
PORTION OF THE CIRCULATION. THERE IS EVIDENCE THAT SOME COLD AIR
HAS WRAPPED AROUND THE SOUTHWESTERN PORTION OF THE CIRCULATION...
BUT THERE IS NO INDICATION THAT IT HAS PENETRATED THE INNER CORE.
MELISSA WILL BE MOVING OVER SEA SURFACE TEMPERATURES OF 17-18
DEGREES CELSIUS LATER TODAY AND THE DRIER AND COOLER AIR MASS WEST
OF THE CYCLONE SHOULD WRAP FURTHER AROUND THE CIRCULATION...CAUSING
MELISSA TO BECOME POST-TROPICAL LATER TODAY. THE CYCLONE IS LIKELY
TO CHANGE LITTLE IN STRENGTH DURING THE NEXT 24 HOURS...BUT GRADUAL
WEAKENING IS EXPECTED BY LATE FRIDAY. THE POST-TROPICAL CYCLONE
SHOULD DISSIPATE OVER THE EASTERN ATLANTIC IN ABOUT THREE DAYS.
 
THE INITIAL MOTION IS EAST-NORTHEAST AT 28 KT. THE CYCLONE IS
FORECAST TO MOVE QUICKLY EAST-NORTHEASTWARD TO EASTWARD WITHIN THE
MID-LATITUDE WESTERLY FLOW DURING THE NEXT DAY OR SO.  AFTER THAT
TIME...THE POST-TROPICAL CYCLONE IS EXPECTED TO SLOW DOWN AND TURN
SOUTHEASTWARD IN WEAKER NORTHWESTERLY FLOW AROUND THE NORTHEASTERN
PORTION OF A BUILDING MID-LEVEL RIDGE OVER THE EASTERN ATLANTIC.
THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO AND LITTLE
CHANGE WAS REQUIRED FROM THE PREVIOUS NHC ADVISORY.
 
GALE-FORCE WINDS ARE EXPECTED TO SPREAD ACROSS PORTIONS OF THE
WESTERN AND CENTRAL AZORES THIS AFTERNOON AND TONIGHT.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 40.0N  34.8W   45 KT  50 MPH
 12H  22/0000Z 41.1N  30.0W   45 KT  50 MPH...POST-TROPICAL
 24H  22/1200Z 42.0N  24.3W   45 KT  50 MPH...POST-TROP/EXTRATROP
 36H  23/0000Z 42.2N  20.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
 48H  23/1200Z 41.2N  17.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
 72H  24/1200Z...DISSIPATED
 
$$
FORECASTER BROWN