000 WTNT41 KNHC 010248 TCDAT1 HURRICANE OPHELIA DISCUSSION NUMBER 34 NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011 1100 PM AST FRI SEP 30 2011 DURING THE PAST SEVERAL HOURS...THE EYE OF OPHELIA HAS BECOME WARMER WITH CONVECTIVE ACTIVITY IN THE EYEWALL STAYING DEEP. DVORAK ESTIMATES HAVE INCREASED SLIGHTLY...RANGING FROM 102-112 KT...SO THE INITIAL WIND SPEED WILL NUDGED UPWARD TO 105 KT. VERTICAL WIND SHEAR AND SSTS ARE EXPECTED TO REMAIN AT ABOUT THE SAME VALUES DURING THE NEXT DAY OR SO...SO LITTLE CHANGE IN INTENSITY IS FORECAST FOR THAT PERIOD. A STEADY WEAKENING SHOULD COMMENCE THEREAFTER DUE TO INCREASING SOUTHWESTERLY SHEAR AND DECREASING WATER TEMPERATURES. AFTER DAY 2...A COMBINATION OF VERY COLD WATERS AND STRONG SHEAR SHOULD PROMOTE RAPID WEAKENING OF OPHELIA AND EXTRATROPICAL TRANSITION IN A BAROCLINIC LOW-LEVEL ENVIRONMENT NEAR THE CANADIAN MARITIMES. THE OFFICIAL FORECAST IS VERY CLOSE TO THE PREVIOUS ONE AND THE DYNAMICAL MODEL CONSENSUS. OPHELIA IS MOVING DUE NORTH AT ABOUT 15 KT. THE CYCLONE SHOULD HAVE A GRADUAL INCREASE IN FORWARD SPEED DURING THE NEXT FEW DAYS AS THE STEERING CURRENTS BECOME STRONGER BETWEEN A DEEP MID-LATITUDE TROUGH OVER THE EASTERN UNITED STATES AND A RIDGE OVER THE CENTRAL ATLANTIC OCEAN. LITTLE CHANGE WAS MADE TO THE OFFICIAL FORECAST FOR THE FIRST 24 TO 36 HOURS AS MODEL GUIDANCE IS IN VERY GOOD AGREEMENT. AFTER THAT TIME...THERE HAS BEEN A NOTABLE SHIFT IN THE LATEST GUIDANCE TO THE LEFT...SOMEWHAT SIMILAR TO LAST NIGHT...WITH THE GLOBAL MODELS SHOWING OPHELIA COMING CLOSER TO SOUTHEASTERN NEWFOUNDLAND. IN GENERAL...THE GUIDANCE HAS BEEN TRENDING TOWARD THE ECMWF SOLUTION...AND THE NHC FORECAST WILL BE SHIFTED TO THE NORTHWEST BEYOND 36 HOURS. FUTURE LEFTWARD ADJUSTMENTS MIGHT HAVE TO BE MADE BECAUSE THE NEW FORECAST IS STILL TO THE RIGHT OF THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 26.2N 63.1W 105 KT 120 MPH 12H 01/1200Z 28.5N 63.1W 105 KT 120 MPH 24H 02/0000Z 32.4N 62.5W 100 KT 115 MPH 36H 02/1200Z 37.2N 61.3W 90 KT 105 MPH 48H 03/0000Z 42.5N 59.0W 80 KT 90 MPH 72H 04/0000Z 50.0N 42.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 05/0000Z...ABSORBED $$ FORECASTER BLAKE