Hurricane FLORENCE

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HURRICANE FLORENCE DISCUSSION NUMBER  33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062006
500 PM EDT MON SEP 11 2006
 
CLOUD TOPS HAVE BEEN WARMING DURING THE PAST FEW HOURS AND RADAR
IMAGERY FROM BERMUDA INDICATES AN EYE THAT IS OPEN TO THE EAST.
GIVEN THE STRONG WINDS REPORTED ACROSS BERMUDA...WE ARE RELUCTANT
TO DECREASE THE WINDS AT THIS TIME.  SOUTHWESTERLY SHEAR AND COOLER
SSTS ARE EXPECTED TO IMPART A GRADUAL WEAKENING DURING THE NEXT 24
HOURS. AS FLORENCE BECOMES EXTRATROPICAL IN ABOUT 36 TO 48 HOURS...
IT WILL LIKELY INTERACT WITH A SHORT WAVE IN THE WESTERLIES WHICH
WILL PROBABLY KEEP THE EXTRATROPICAL CYCLONE LARGE AND VERY
POWERFUL FOR SEVERAL MORE DAYS.
 
THE INITIAL MOTION ESTIMATE IS 020/14.  FLORENCE IS BEGINNING TO
ACCELERATE NORTH-NORTHEASTWARD AHEAD OF A MID-LEVEL TROPOSPHERIC
TROUGH OVER THE CANADIAN MARITIMES.  DYNAMICAL TRACK MODEL GUIDANCE
REMAINS IN FAIRLY GOOD AGREEMENT.  HOWEVER...THE MODELS ARE NOW
LEANING A LITTLE MORE TOWARD NEWFOUNDLAND IN ABOUT 48 HOURS BEFORE
DEPICTING A HARD RIGHT TURN INTO THE NORTH ATLANTIC.  THEREFORE...
THE OFFICIAL FORECAST IS SHIFTED A LITTLE TO THE LEFT IN ABOUT 2
DAYS...BUT IS OTHERWISE SIMILAR TO THE PREVIOUS NHC TRACK.
 
A TIGHT PRESSURE GRADIENT BETWEEN FLORENCE AND A STRONG HIGH
CENTERED OVER SOUTHEASTERN CANADA IS PRODUCING BRISK NORTHEASTERLY
WINDS ALONG THE EAST COAST OF THE UNITED STATES.  THIS IS EXPECTED
TO CAUSE VERY ROUGH AND DANGEROUS SURF CONDITIONS ALONG NEARLY
THE ENTIRE EAST COAST OF NORTH AMERICA FOR THE NEXT SEVERAL DAYS.
THE RADII OF 12-FT SEAS SHOWN IN THE FORECAST/ADVISORY DOES NOT
FULLY ACCOUNT FOR THE HUGE AREA OF HIGH WAVES INDIRECTLY ASSOCIATED
WITH THIS HURRICANE.
 
EVEN THOUGH FLORENCE PASSED ABOUT 48 N MI WEST AND NORTHWEST OF
BERMUDA...THEY WERE VERY CLOSE TO THE RADIUS OF MAXIMUM WINDS AND
OBSERVATIONS INDICATE THAT THE ISLAND EXPERIENCE HURRICANE FORCE
WINDS.  THIS IS A GOOD REMINDER THAT A HURRICANE IS NOT JUST A
POINT ON THE MAP...AND THAT DAMAGING WINDS CAN BE EXPERIENCED WELL
AWAY FROM THE CENTER.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/2100Z 34.4N  64.8W    80 KT
 12HR VT     12/0600Z 36.2N  63.8W    70 KT
 24HR VT     12/1800Z 38.7N  61.9W    65 KT
 36HR VT     13/0600Z 42.0N  58.5W    65 KT
 48HR VT     13/1800Z 45.2N  54.8W    60 KT...EXTRATROPICAL
 72HR VT     14/1800Z 49.0N  42.0W    55 KT...EXTRATROPICAL
 96HR VT     15/1800Z 51.0N  25.0W    50 KT...EXTRATROPICAL
120HR VT     16/1800Z...ABSORBED
 
$$
FORECASTER BROWN/PASCH
 
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