000 WTNT44 KNHC 130243 TCDAT4 TROPICAL STORM NADINE DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142012 1100 PM AST WED SEP 12 2012 THE OVERALL CONVECTIVE PATTERN HAS IMPROVED SINCE THE PREVIOUS ADVISORY AND CONVECTIVE BANDING NOW WRAPS ALMOST COMPLETELY AROUND THE CENTER. THE CDO HAS ALSO INCREASED IN SIZE AND TOPS HAVE COOLED BELOW -80C NEAR THE CENTER...AND IN MOST OF THE NORTHEAST QUADRANT. SATELLITE INTENSITY ESTIMATES WERE A CONSENSUS T3.5/55 KT AT 00Z... BUT THE BANDING HAS CONTINUED TO INCREASE SINCE THEN. THE LATEST UW-CIMSS ADT INTENSITY ESTIMATE IS T3.9/63 KT. HOWEVER...WITH NO RECENT MICROWAVE DATA THAT WOULD BE USEFUL IN DETERMINING IF NADINE HAS AN EYE UNDERNEATH THE COLD CLOUD CANOPY...THE INITIAL INTENSITY IS BEING HELD JUST BELOW HURRICANE STRENGTH AT 60 KT. THE INITIAL MOTION IS STILL NORTHWESTWARD...OR 305/14 KT. OTHER THAN MINOR WOBBLES OVER THE PAST FEW HOURS...NADINE HAS BASICALLY BEEN ON TRACK. FOR THE NEXT 72 HOURS OR SO...NADINE SHOULD CONTINUE TO MOVE NORTHWESTWARD AND THEN NORTHWARD AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE THAT IS ORIENTED EAST-WEST ALONG 32-33N LATITUDE. AFTER THAT...THE CYCLONE IS FORECAST TO COME UNDER THE INFLUENCE OF WESTERLY MID- TO UPPER-LEVEL FLOW ON THE EAST SIDE OF AN EASTWARD-MOVING DEEP-LAYER TROUGH THAT IS CURRENTLY LOCATED OFF THE EAST COAST OF NORTH AMERICA. OTHER THAN A SLIGHT SOUTHWARD SHIFT IN THE FORECAST TRACK AT DAYS 4 AND 5...THE PREVIOUS ADVISORY TRACK HAS REMAINED UNCHANGED. THE OFFICIAL FORECAST TRACK IS CLOSE TO THE CONSENSUS MODELS TVCN AND TV15 THROUGH 72 HOURS...AND THEN LIES WELL TO THE RIGHT OF THOSE MODELS DUE TO THE GFDL MODEL BEING A SIGNIFICANT OUTLIER WITH ITS FAST NORTHWARD TRACK AT DAYS 4/5. NADINE HAS BEEN STRENGTHENING OVER THE PAST 24 HOURS AT JUST BELOW THE RATE OF RAPID INTENSIFICATION. THE CYCLONE POSSESSES AN IMPRESSIVE OUTFLOW REGIME THAT SHOULD CONTINUE TO EXPAND AS NADINE MOVES BETWEEN A LARGE UPPER-LEVEL LOW TO ITS NORTHEAST AND A SMALLER LOW TO ITS WEST. THE COMBINATION OF A FAVORABLE OUTFLOW PATTERN AND RELATIVELY LOW VERTICAL WIND SHEAR SHOULD ALLOW FOR SOME ADDITIONAL INTENSIFICATION TO OCCUR FOR THE NEXT 24 HOURS OR SO. AFTER THAT...HOWEVER...A SHARP INCREASE IN WESTERLY SHEAR IS EXPECTED AHEAD OF THE AFOREMENTIONED DEEP-LAYER TROUGH APPROACHING FROM THE WEST. THIS SHOULD RESULT IN A CAPPING OF THE INTENSITY BY 36 HOURS...AND POSSIBLY INDUCE SOME SLIGHT WEAKENING AT 48 HOURS AND BEYOND. THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY...AND LIES CLOSE TO THE INTENSITY CONSENSUS MODEL IVCN. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 20.7N 50.1W 60 KT 70 MPH 12H 13/1200Z 22.1N 51.5W 70 KT 80 MPH 24H 14/0000Z 24.2N 53.2W 75 KT 85 MPH 36H 14/1200Z 26.4N 54.0W 75 KT 85 MPH 48H 15/0000Z 28.6N 53.8W 70 KT 80 MPH 72H 16/0000Z 30.9N 50.2W 65 KT 75 MPH 96H 17/0000Z 31.8N 44.5W 65 KT 75 MPH 120H 18/0000Z 32.9N 38.0W 65 KT 75 MPH $$ FORECASTER STEWART