885 
 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
  
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 FORECASTER BLAKE