Hurricane OPHELIA

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TROPICAL STORM OPHELIA DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT MON SEP 12 2005
 
THE STRUCTURE OF OPHELIA HAS CHANGED LITTLE OVER THE PAST SEVERAL
HOURS...ALTHOUGH THE CONVECTIVE TOPS ARE A LITTLE COOLER THAN THEY
WERE EARLIER.  A NOAA AIRCRAFT MEASURED SURFACE WINDS OF 60 KT
NORTH OF THE CENTER WITH THE STEPPED FREQUENCY MICROWAVE RADIOMETER
AROUND 2238Z...AND AN AIR FORCE AIRCRAFT MEASURED 700 MB WINDS OF
72 KT.  BASED ON THESE DATA...THE INITIAL INTENSITY REMAINS JUST
BELOW HURRICANE STRENGTH.  WHILE THE STRUCTURE OF OPHELIA...WITH A
RADIUS OF MAXIMUM WIND OF 45-60 NMI...AS WELL AS MARGINAL WATER
TEMPERATURES...ARGUES AGAINST ANY RAPID OR LARGE INTENSITY
INCREASES...IT WOULD TAKE VERY LITTLE FOR OPHELIA TO REGAIN
HURRICANE STATUS.  WITH BOTH THE SHIPS AND GFDL GUIDANCE INDICATING
SUCH...A HURRICANE WARNING AT THIS TIME IS THE PRUDENT COURSE OF
ACTION.

THE MOTION REMAINS SLOW AND ERRATIC...WITH AN INITIAL MOTION
ESTIMATED AT 290/3.  RAOB DATA AT 0Z SUGGEST THAT HIGH PRESSURE TO
THE NORTHWEST OF OPHELIA IS WEAKENING WITH THE APPROACH A MID-LEVEL
TROUGH.  MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT THAT THE
INFLUENCE OF THE HIGH WILL SHORTLY DIMINISH AND OPHELIA WILL BEGIN
TO TURN NORTHWARD AND THEN NORTHEASTWARD OVER THE NEXT 48
HOURS...ALTHOUGH WITH VERY LITTLE ACCELERATION.  THIS COULD RESULT
IN A VERY SLOW PROGRESSION OF THE SYSTEM ACROSS THE HURRICANE
WARNING AREA.  GIVEN THE SIZE OF THE WIND FIELD...WINDS AT OR NEAR
HURRICANE STRENGTH COULD BE A PROLONGED EXPERIENCE IN MANY
LOCATIONS.
 
FORECASTER FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      13/0300Z 31.8N  77.9W    60 KT
 12HR VT     13/1200Z 32.4N  78.1W    65 KT
 24HR VT     14/0000Z 32.9N  78.1W    65 KT
 36HR VT     14/1200Z 33.7N  77.8W    65 KT
 48HR VT     15/0000Z 34.6N  77.2W    65 KT
 72HR VT     16/0000Z 36.0N  75.5W    55 KT
 96HR VT     17/0000Z 38.0N  72.0W    50 KT
120HR VT     18/0000Z 42.0N  66.0W    40 KT...EXTRATROPICAL
 
 
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