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#546232 (Received by flhurricane at: 10:47 AM 28.Sep.2012) TCDAT4 HURRICANE NADINE DISCUSSION NUMBER 64 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142012 1100 AM AST FRI SEP 28 2012 MICROWAVE SATELLITE IMAGERY INDICATES THAT NADINE HAS DEVELOPED AN EYE DURING THE PAST SEVERAL HOURS...WITH THIS FEATURE ALSO APPEARING IN CONVENTIONAL IMAGERY. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE INCREASED TO 65 KT...WHILE RECENT AMSU-BASED INTENSITY ESTIMATES FROM CIMSS AND CIRA HAVE BEEN IN THE 60-75 KT RANGE. BASED ON THESE DATA...NADINE HAS REGAINED HURRICANE STATUS AND THE INITIAL INTENSITY IS INCREASED TO 65 KT. THE INITIAL MOTION IS NOW 310/7. FOR THE NEXT 48 HR OR SO NADINE SHOULD MOVE GENERALLY NORTH-NORTHWESTWARD BETWEEN A DEEP-LAYER RIDGE OVER THE EASTERN ATLANTIC AND A MID/UPPER-LEVEL LOW CURRENTLY LOCATED NEAR 32N48W. THE GLOBAL MODELS FORECAST NADINE TO MERGE OR MOVE UNDER THIS LOW IN ABOUT 72 HR...WITH THE SYSTEM MOVING SLOWLY IN AN AREA OF LIGHT STEERING CURRENTS JUST SOUTH OF THE MAIN BRANCH OF THE WESTERLIES. THE TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH 48 HR...BUT DIVERGES THERAFTER. THE NOGAPS AND THE CANADIAN MODELS SHOW A SOUTHWESTWARD MOTION BY 120 HR. THE REST OF THE DYNAMICAL MODELS SHOW SOME TYPE OF EASTWARD MOTION BY THAT TIME...WITH THE ECMWF AND UKMET NOW SUPPORTING THIS SCENARIO. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK...SHOWING A NORTH- NORTHWESTWARD MOTION THROUGH 48 HR...FOLLOWED BY A SLOW NORTHWARD AND EASTWARD DRIFT. THE NEW TRACK LIES CLOSE TO THE VARIOUS CONSENSUS MODELS. THERE REMAINS UNCERTAINTY AS TO HOW MUCH SHEAR NADINE WILL ENCOUNTER DURING THE NEXT 24-36 HR...AS SEVERAL OF THE GLOBAL MODELS FORECAST AN UPPER-LEVEL SHORTWAVE TROUGH NEAR THE HURRICANE THAT COULD SHIELD IT FROM THE WORST OF THE FORECAST SOUTHWESTERLY SHEAR. THE SHIPS...LGEM...AND INTENSITY CONSENSUS MODELS SHOW MODEST STRENGTHENING DURING THIS TIME...AND THE INTENSITY FORECAST FOLLOWS THIS SCENARIO. THE CYCLONE SHOULD ENCOUNTER COOLER SEA SURFACE TEMPERATURES IN 24 HR OR SO...WHICH SHOULD STOP INTENSIFICATION. BY THE END OF THE FORECAST PERIOD...INCREASING NORTHERLY SHEAR AND EVEN COLDER SEA SURFACE TEMPERATURES SHOULD LEAD TO A STEADY WEAKENING. THE INITIAL AND FORECAST WIND RADII HAVE BEEN REVISED BASED ON A RECENT ASCAT OVERPASS. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 29.6N 34.7W 65 KT 75 MPH 12H 29/0000Z 30.5N 35.3W 70 KT 80 MPH 24H 29/1200Z 32.3N 36.1W 70 KT 80 MPH 36H 30/0000Z 34.2N 36.6W 70 KT 80 MPH 48H 30/1200Z 35.7N 37.2W 65 KT 75 MPH 72H 01/1200Z 36.5N 37.5W 60 KT 70 MPH 96H 02/1200Z 36.5N 37.0W 55 KT 65 MPH 120H 03/1200Z 36.5N 36.0W 45 KT 50 MPH $$ FORECASTER BEVEN |