Hurricane HENRIETTE

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HURRICANE HENRIETTE DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP082013
800 AM PDT TUE AUG 06 2013
 
HENRIETTE HAS CONTINUED TO STRENGTHEN OVERNIGHT AND EARLY THIS
MORNING.  RECENT MICROWAVE IMAGES HAVE REVEALED A WELL-DEFINED 
EYE...WHICH HAS ALSO BEEN SEEN INTERMITTENTLY IN NIGHT TIME 
VISIBLE IMAGERY THIS MORNING.  DVORAK SATELLITE INTENSITY 
ESTIMATES ARE 65 KT FROM SAB...77 KT FROM TAFB...AND 82 KT FROM
UW/CIMSS ADT.  BASED ON THESE ESTIMATES...THE INITIAL INTENSITY 
IS RAISED TO 70 KT. 

THE HURRICANE HAS BEEN MOVING ON A MOTION BETWEEN WEST-NORTHWEST AND
NORTHWEST OVERNIGHT.  SMOOTHING THROUGH THE WOBBLES...THE INITIAL
MOTION ESTIMATE FOR THIS ADVISORY IS 305/9 KT.  HENRIETTE IS
FORECAST TO CONTINUE ON THIS GENERAL HEADING AND SPEED FOR THE NEXT
36 HOURS AS IT MOVES TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE
BETWEEN 135W AND 140W LONGITUDE.  IN A COUPLE OF DAYS...THE RIDGE
IS EXPECTED TO BUILD BACK TO THE NORTH OF THE HURRICANE WHICH 
WILL CAUSE HENRIETTE TO TURN WESTWARD...AND POSSIBLY WEST-
SOUTHWESTWARD BY LATE IN THE PERIOD.  THE TRACK GUIDANCE IS IN
GOOD AGREEMENT THROUGH 72 HOURS...EXCEPT FOR SOME DIFFERENCES IN
THE FORWARD SPEED OF THE CYCLONE.  LATER IN THE PERIOD...THE SPREAD
BECOMES LARGER WITH THE MODELS THAT WEAKEN HENRIETTE SOONER SHOWING
A MORE SOUTHERLY TRACK.  THE NHC FORECAST LIES NEAR THE MIDDLE OF
THE GUIDANCE ENVELOPE AND IS CLOSE TO THE DYNAMICAL MODEL
CONSENSUS.
 
DURING THE NEXT 24 HOURS...HENRIETTE SHOULD REMAIN OVER WARMER
WATERS AND IN A MOIST ATMOSPHERE.  THIS SHOULD ALLOW FOR SOME
ADDITIONAL STRENGTHENING...AND THE NHC INTENSITY FORECASTS CALLS
FOR A PEAK INTENSITY OF 80 KT IN ABOUT 12 HOURS.  AFTER THAT
TIME...HENRIETTE WILL BE MOVING OVER SSTS OF 25 TO 26 DEGREES
CELSIUS AND INTO A DRIER AND MORE STABLE AIRMASS.  THIS SHOULD
RESULT IN GRADUAL WEAKENING OF THE CYCLONE DURING THE REMAINDER
OF THE FORECAST PERIOD.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/1500Z 14.2N 131.5W   70 KT  80 MPH
 12H  07/0000Z 15.1N 132.8W   80 KT  90 MPH
 24H  07/1200Z 16.0N 134.4W   75 KT  85 MPH
 36H  08/0000Z 16.9N 136.1W   70 KT  80 MPH
 48H  08/1200Z 17.3N 138.1W   60 KT  70 MPH
 72H  09/1200Z 17.3N 142.0W   50 KT  60 MPH
 96H  10/1200Z 16.8N 146.5W   35 KT  40 MPH
120H  11/1200Z 16.5N 151.5W   30 KT  35 MPH
 
$$
FORECASTER BROWN
 
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