000 WTNT42 KNHC 170246 TCDAT2 HURRICANE RAFAEL DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172012 1100 PM AST TUE OCT 16 2012 NOAA HURRICANE HUNTER OBSERVATIONS FROM A FEW HOURS AGO INDICATED THAT RAFAEL WAS MORE OR LESS MAINTINING ITS INTENSITY...ALTHOUGH THE CYCLONE WAS BECOMING TILTED NORTH-NORTHEASTWARD WITH HEIGHT. MAXIMUM WINDS ARE HELD AT 75 KT FOR THIS ADVISORY...ALTHOUGH THE TILT OF THE VORTEX SUGGESTS THAT WEAKENING WILL SOON OCCUR. COOLER WATERS LIE AHEAD OF THE CYCLONE...WHICH SHOULD ALSO INDUCE WEAKENING. THE LATEST GFS MODEL OUTPUT SHOWS RAFAEL BECOMING EMBEDDED WITHIN A FRONTAL ZONE BY 36 HOURS...AND THE OFFICIAL FORECAST SHOWS THE SYSTEM AS AN EXTRATROPICAL CYCLONE BY THAT TIME. THE OFFICIAL INTENSITY FORECAST IS SOMEWHAT ABOVE THE MODEL CONSENSUS...ESPECIALLY AFTER 24 HOURS...BASED ON THE PRESUMPTION THAT THE CYCLONE WILL SOON BE DERIVING SOME ENERGY FROM BAROCLINIC SOURCES. RAFAEL CONTINUES TO ACCELERATE...AND THE INITIAL MOTION ESTIMATE IS NOW 030/25. THE TRACK FORECAST REASONING REMAINS BASICALLY UNCHANGED FROM THE PREVIOUS ADVISORY. RAFAEL OR ITS POST-TROPICAL COUNTERPART SHOULD CONTINUE TO ACCELERATE IN THE FLOW TO THE SOUTHEAST AND SOUTH OF A LARGE MID-TROPOSPHERIC LOW PRESSURE SYSTEM OVER THE NORTH ATLANTIC FOR THE NEXT FEW DAYS. LATER IN THE FORECAST PERIOD...POST-TROPICAL RAFAEL IS FORECAST TO SLOW DOWN AND ROTATE CYCLONICALLY AROUND THE LOW. THE OFFICIAL TRACK FORECAST IS SIMILAR TO THE PREVIOUS ONE...AND CLOSE TO THE LATEST GFS PREDICTION...AS WELL AS THE DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 17/0300Z 32.4N 62.5W 75 KT 85 MPH 12H 17/1200Z 36.2N 59.9W 70 KT 80 MPH 24H 18/0000Z 40.9N 54.4W 65 KT 75 MPH 36H 18/1200Z 44.9N 46.2W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 19/0000Z 48.5N 36.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 20/0000Z 53.5N 31.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 21/0000Z 49.0N 34.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 22/0000Z 43.0N 30.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER PASCH