000 WTNT44 KNHC 300846 TCDAT4 HURRICANE NADINE DISCUSSION NUMBER 71 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142012 500 AM AST SUN SEP 30 2012 NADINE APPEARS TO HAVE GAINED A LITTLE MORE STRENGTH THIS MORNING. GEOSTATIONARY SATELLITE IMAGES INDICATE THAT DEEP CONVECTION HAS EXPANDED AND BECOME MORE SYMMETRIC AROUND THE RAGGED EYE DURING THE LAST SEVERAL HOURS. DVORAK CLASSIFICATIONS ARE T4.5/77 KT FROM TAFB AND SAB...AND ADT VALUES FROM UW-CIMSS ARE 4.7/82 KT. BASED ON THESE ESTIMATES...THE INITIAL WIND SPEED IS NUDGED UPWARD TO 80 KT. THE HURRICANE IS MOVING NORTH-NORTHWESTWARD AT ABOUT 10 KT ON THE WESTERN PERIPHERY OF A MID-LEVEL RIDGE LOCATED OVER THE EASTERN ATLANTIC OCEAN. THE STEERING CURRENTS...HOWEVER...ARE EXPECTED TO WEAKEN LATER TODAY AS NADINE BECOMES TRAPPED BETWEEN A PAIR OF RIDGES TO ITS EAST AND WEST AND A TROUGH TO ITS NORTH. THIS COMPLEX PATTERN WILL LIKELY CAUSE THE HURRICANE TO MAKE A CYCLONIC LOOP OR MOVE LITTLE DURING THE NEXT 2 TO 3 DAYS. AFTER THAT TIME...A LARGE MID- TO UPPER-LEVEL LOW CURRENTLY LOCATED OVER THE NORTHEASTERN UNITED STATES IS EXPECTED TO CAUSE NADINE TO ACCELERATE NORTHEASTWARD. LITTLE CHANGE WAS MADE TO THE PREVIOUS TRACK FORECAST FOR THE FIRST FEW DAYS...AND THE OFFICIAL FORECAST IS CLOSE TO A BLEND OF THE GFS AND ECMWF MODELS DURING THAT TIME. AT DAYS 4 AND 5...THE MODELS HAVE TRENDED FASTER...AND THE OFFICIAL FORECAST IS ADJUSTED ACCORDINGLY. IT SHOULD BE NOTED THAT THERE REMAINS CONSIDERABLE DIFFERENCES AMONG THE MODEL SOLUTIONS IN HOW NADINE INTERACTS WITH THE AFOREMENTIONED MID- TO UPPER-LEVEL LOW. ENVIRONMENTAL CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH OVER THE NEXT 12 TO 24 HOURS...THEREFORE...LITTLE CHANGE IN STRENGTH IS ANTICIPATED. AFTER THAT...A GRADUAL WEAKENING IS FORECAST... FOLLOWING THE TREND OF THE GUIDANCE...AS THE SHEAR IS EXPECTED TO INCREASE WHEN THE MID- TO UPPER-LEVEL LOW NEARS THE CYCLONE. THE NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND IS FAIRLY CLOSE TO THE CONSENSUS AIDS. MOST OF THE MODELS SHOW NADINE TRANSITIONING TO A POST-TROPICAL CYCLONE IN 4 TO 5 DAYS. FORECAST POSITIONS AND MAX WINDS INIT 30/0900Z 36.6N 37.8W 80 KT 90 MPH 12H 30/1800Z 37.2N 38.5W 80 KT 90 MPH 24H 01/0600Z 36.9N 39.1W 75 KT 85 MPH 36H 01/1800Z 36.1N 39.1W 70 KT 80 MPH 48H 02/0600Z 35.4N 38.7W 65 KT 75 MPH 72H 03/0600Z 35.4N 36.5W 60 KT 70 MPH 96H 04/0600Z 38.5N 32.0W 55 KT 65 MPH 120H 05/0600Z 46.0N 28.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ FORECASTER CANGIALOSI