Thursday, August 26, 2010

Bye Bye Danielle

 
 
ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
HURRICANE DANIELLE DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062010
500 PM AST THU AUG 26 2010
 
SATELLITE IMAGERY THIS AFTERNOON INDICATES THAT DANIELLE HAS
DEVELOPED A WELL-DEFINED 20 NM WIDE EYE WITH CLOUD TOPS TO -75C IN
THE NORTHWESTERN EYEWALL.  SATELLITE INTENSITY ESTIMATES AT 18Z WERE
90 KT FROM TAFB AND SAB...AND SINCE THAT TIME THE SATELLITE
APPEARANCE OF THE HURRICANE HAS IMPROVED.  THUS...THE INITIAL
INTENSITY IS INCREASED TO 95 KT.  THE CIRRUS IS FAIR TO GOOD IN ALL
DIRECTIONS EXCEPT TO THE SOUTH.
 
THE INITIAL MOTION IS 315/13.  FOR THE NEXT 36 HR...DANIELLE SHOULD
BE STEERED GENERALLY NORTHWESTWARD BY A LOW/MID-LEVEL RIDGE PASSING
TO THE NORTH AND NORTHEAST OF THE HURRICANE.  AFTER THAT...A LARGE
MID/UPPER-LEVEL TROUGH MOVING THROUGH THE NORTHEASTERN UNITED
STATES AND THE CANADIAN MARITIMES IS EXPECTED TO CAUSE DANIELLE TO
RECURVE TOWARD THE NORTHEAST.  WITH TWO EXCEPTIONS...THE TRACK
MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO.  THOSE
EXCEPTIONS ARE THE NOGAPS AND GFDN...WHICH FORECAST DANIELLE TO
MOVE NORTHWARD AND THEN STALL NORTH OF BERMUDA.  THE NEW TRACK
FORECAST FOLLOWS THE RECURVATURE SCENARIO AND CALLS FOR DANIELLE
TO GRADUALLY ACCELERATE TOWARD THE NORTHEAST AFTER 48 HR.  THE NEW
TRACK IS STILL TO THE LEFT AND SLOWER THAN THE BULK OF THE
DYNAMICAL MODELS...AND ADDITIONAL ADJUSTMENTS MAY BE NEEDED ON THE
NEXT ADVISORY.
 
ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SUGGEST THAT
DANIELLE IS EXPERIENCING 10-15 KT OF SOUTHERLY VERTICAL WIND
SHEAR.  THE HURRICANE SHOULD CONTINUE IN A LIGHT/MODERATE SHEAR
ENVIRONMENT FOR 36-48 HR BEFORE ENCOUNTERING STRONGER SHEAR
ASSOCIATED WITH THE UPPER-LEVEL TROUGH.  ALL INTENSITY GUIDANCE
FORECAST STRENGTHENING FOR 24 HR OR SO AND THE INTENSITY FORECAST
FOLLOWS THAT SCENARIO...WITH A PEAK INTENSITY OF 105 KT IN 24 HR.
AFTER 48 HR...INCREASING SHEAR AND DECREASING SEA SURFACE
TEMPERATURES SHOULD CAUSE STEADY WEAKENING.  EXTRATROPICAL
TRANSITION MAY BE UNDERWAY BY 120 HR...BUT IS EXPECTED TO BE
COMPLETED AFTER THE END OF THE FORECAST PERIOD.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/2100Z 25.2N  57.0W    95 KT
 12HR VT     27/0600Z 26.0N  58.3W    95 KT
 24HR VT     27/1800Z 27.3N  60.0W   100 KT
 36HR VT     28/0600Z 28.6N  61.1W   105 KT
 48HR VT     28/1800Z 30.2N  61.2W   105 KT
 72HR VT     29/1800Z 34.0N  59.5W    95 KT
 96HR VT     30/1800Z 37.5N  56.5W    80 KT
120HR VT     31/1800Z 39.5N  51.0W    65 KT
 
$$
FORECASTER BEVEN
NNNN
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It now seems all but certain that, other than the Island of Bermuda, Hurricane Danielle
will now miss ALL land areas in North America. As such this will be my last regular 
daily update on Danielle, unless the proceeding projections somehow changes.