000 WTNT44 KNHC 191441 TCDAT4 SUBTROPICAL STORM MELISSA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142013 1100 AM AST TUE NOV 19 2013 VARIOUS SATELLITE DATA INDICATE THAT THE LOW-LEVEL CENTER OF MELISSA IS LOCATED ABOUT 20 NMI SOUTHEAST OF THE MID- AND UPPER-LEVEL CIRCULATIONS. HOWEVER...SOME WEAK ANTICYCLONIC OUTFLOW IN THE INNER CORE REGION HAS DEVELOPED DURING THE PAST COUPLE OF HOURS...AND THE CYCLONE APPEARS TO BE SEPARATING FROM THE ELONGATED PARENT CLOUD BAND THAT IS LOCATED WELL TO THE EAST OF MELISSA. THESE INDICATORS SUGGEST THAT MELISSA IS TRYING TO MAKE TRANSITION TO A TROPICAL CYCLONE. THE INITIAL INTENSITY IS BEING MAINTAINED AT 55 KT BASED ON A 55-KT SUBTROPICAL SATELLITE CLASSIFICATION FROM TAFB. THE INITIAL MOTION ESTIMATE IS 010/09 KT. A STRONG COLD FRONT AND ASSOCIATED DEEP-LAYER TROUGH CURRENTLY APPROACHING BERMUDA FROM THE WEST SHOULD BEGIN TO ACCELERATE MELISSA NORTHEASTWARD DURING THE NEXT 6 HOURS OR SO...AND CONTINUE THAT MOTION THROUGH 72 HOURS. BY 96-120 HOURS...THE EXTRATROPICAL REMNANT OF MELISSA IS EXPECTED TO MOVE NORTHWARD AND MERGE WITH A FRONTAL SYSTEM...AND CEASE TO EXIST AS A SEPARATE ENTITY. NHC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ON THIS DEVELOPING TRACK SCENARIO...AND THE OFFICIAL FORECAST TRACK IS CLOSE TO THE PREVIOUS ADVISORY AND THE MULTI-MODEL CONSENSUS TVCA AND THE FLORIDA STATE SUPERENSEMBLE MODEL. THE LOW- AND UPPER-LEVEL CIRCULATION CENTERS ARE EXPECTED TO BECOME JUXTAPOSED DURING THE NEXT 6-12 HOURS WHEN THE VERTICAL WIND SHEAR IS FORECAST TO BE AT ITS LOWEST VALUE OF AROUND 10 KT. THIS SHOULD HELP MELISSA TO TRANSITION FROM A SUBTROPICAL TO A TROPICAL CYCLONE...AND ALSO ALLOW FOR SOME ADDITIONAL STRENGTHENING. IT IS STILL POSSIBLE THAT MELISSA COULD OBTAIN HURRICANE STATUS BEFORE THE CYCLONE REACHES SIGNIFICANTLY COLDER WATER AND MOVES INTO A DRIER AND MORE STABLE AIRMASS IN 24-36 HOURS. THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND CLOSELY FOLLOWS THE INTENSITY CONSENSUS MODEL ICON. TRACK...INTENSITY...AND WIND RADII FORECASTS DURING THE EXTRATROPICAL STAGE AT 48 HOURS AND BEYOND WERE COORDINATED WITH THE NOAA OCEAN PREDICTION CENTER. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 31.9N 54.6W 55 KT 65 MPH 12H 20/0000Z 33.9N 52.8W 60 KT 70 MPH 24H 20/1200Z 36.6N 48.8W 60 KT 70 MPH 36H 21/0000Z 39.5N 43.4W 55 KT 65 MPH 48H 21/1200Z 42.2N 37.9W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 22/1200Z 46.5N 29.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 23/1200Z 53.2N 26.8W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 24/1200Z...DISSIPATED $$ FORECASTER STEWART