000 WTNT44 KNHC 140243 TCDAT4 TROPICAL STORM NADINE DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142012 1100 PM AST THU SEP 13 2012 THE SATELLITE PRESENTATION OF NADINE HAS NOT CHANGED MUCH OVER THE PAST FEW HOURS...AS THE CLOUD PATTERN IS CHARACTERIZED BY A CDO-LIKE PATTERN WITH NO EVIDENCE OF AN EYE. THE INITIAL INTENSITY REMAINS 60 KT BASED ON A BLEND OF THE LATEST DVORAK ESTIMATES FROM TAFB AND SAB AND RECENT ADT ESTIMATES. THE SIGNALS FOR THE INTENSITY FORECAST ARE MIXED. RECENT WATER VAPOR IMAGERY SHOWS THAT THE OUTFLOW HAS BECOME A LITTLE BETTER ESTABLISHED OVER THE PAST FEW HOURS. HOWEVER...SATELLITE ANALYSIS FROM UW-CIMSS SUGGEST THAT SOUTHWESTERLY SHEAR OF 10 TO 15 KT IS AFFECTING NADINE...WHICH IS CONSISTENT WITH MICROWAVE IMAGERY THAT SHOWS THE LOW-LEVEL CENTER LOCATED SOUTH-SOUTHWEST OF THE DEEP CONVECTION. WHILE THE SHIPS MODEL SHOWS THE SHEAR INCREASING OVER THE CYCLONE IN THE NEXT DAY OR TWO...MOST OF THE GUIDANCE NOW SHOWS NADINE BECOMING A HURRICANE BY 36 HOURS. LATER IN THE PERIOD...THE CYCLONE MAY BE IN A SLIGHTLY MORE FAVORABLE ENVIRONMENT OF MODERATE SOUTHWESTERLY SHEAR OVER WARM SSTS. MOST OF THE GUIDANCE HAS TRENDED UPWARD THIS CYCLE...AND THE INTENSITY FORECAST HAS BEEN ADJUSTED IN THAT DIRECTION AT DAYS 3 THROUGH 5. THE NHC FORECAST IS CLOSE TO THE SHIPS AND LGEM GUIDANCE BUT IS BELOW THE LATEST INTENSITY CONSENSUS MODELS. THE INITIAL MOTION ESTIMATE IS 330/13...AS NADINE IS NOW SITUATED ON THE SOUTHWESTERN PERIPHERY OF A WEAKENING MID-LEVEL RIDGE. THE OVERALL TRACK FORECAST REASONING IS UNCHANGED...AS NADINE WILL MOVE AROUND THE RIDGE IN THE NEXT 24 TO 36 HOURS AND THEN TURN EAST- NORTHEASTWARD OR EASTWARD IN THE MID-LATITUDE WESTERLIES. THE GUIDANCE IS TIGHTLY CLUSTERED THROUGH ABOUT 48 HOURS...AND THE NHC FORECAST IS LARGELY AN UPDATE OF THE PREVIOUS ONE THROUGH THAT TIME. A LARGE SPREAD PERSISTS IN THE TRACK MODELS AT DAYS 3 THROUGH 5. THE GFS...ECMWF...AND FSU SUPERENSEMBLE ARE ON THE SOUTHERN EDGE OF THE GUIDANCE SUITE WHILE THE GFDL CONTINUES TO BE A FAR LEFT OUTLIER SHOWING NADINE TURNING NORTHWARD AFTER 3 DAYS. THE NHC TRACK LATE IN THE PERIOD IS SOUTH OF THE TVCA MULTI-MODEL CONSENSUS AND NORTH OF THE AFOREMENTIONED SOUTHERNMOST MODEL GROUP. THROUGH MOST OF THE PERIOD THE NHC FORECAST IS ALSO A LITTLE FASTER THAN THE PREVIOUS...FOLLOWING THE LEAD OF THE GFS AND ECMWF MODELS. FORECAST POSITIONS AND MAX WINDS INIT 14/0300Z 25.0N 53.7W 60 KT 70 MPH 12H 14/1200Z 26.8N 54.2W 60 KT 70 MPH 24H 15/0000Z 29.1N 54.0W 60 KT 70 MPH 36H 15/1200Z 30.7N 52.7W 65 KT 75 MPH 48H 16/0000Z 31.4N 50.4W 65 KT 75 MPH 72H 17/0000Z 32.3N 44.6W 70 KT 80 MPH 96H 18/0000Z 33.5N 38.5W 70 KT 80 MPH 120H 19/0000Z 35.5N 32.5W 70 KT 80 MPH $$ FORECASTER BRENNAN