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HURRICANE DENNIS DISCUSSION NUMBER  23
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT SUN AUG 29 1999
 
DENNIS IS NOW MOVING NORTHWARD NEAR 9 KNOTS...NEAR THE WESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE.  A LARGE 500 MB TROUGH MOVING
OFF THE NORTHEASTERN U.S. COAST IN 24 HOURS IS EXPECTED TO PROVIDE A
SOUTHWESTERLY STEERING CURRENT THAT SHOULD CAUSE DENNIS TO
GRADUALLY TURN TOWARD THE NORTH-NORTHEAST AND THEN NORTHEAST...
AWAY FROM THE COAST.  THIS IS ALSO INDICATED BY NEARLY ALL OF THE
OBJECTIVE TRACK GUIDANCE. THE CURRENT OFFICIAL TRACK FORECAST IS
SIMILAR TO THE PREVIOUS ONE...ALBEIT SLIGHTLY TO THE RIGHT.

THERE IS STILL SOME CONCERN THAT THE TROUGH WILL PULL OUT LATE IN
THE PERIOD...AND LEAVE DENNIS BEHIND.  THE CURRENT THINKING IS
THAT...IF THIS OCCURS...THE HURRICANE WILL BE WELL EAST OF THE COAST
BY THAT TIME.
 
ON SATELLITE IMAGES...DENNIS HAS BECOME A LITTLE BETTER-ORGANIZED
OVER THE PAST FEW HOURS...ALTHOUGH THE EYE IS STILL SOMEWHAT RAGGED-
LOOKING.  A GPS DROPSONDE...RELEASED INTO THE EYEWALL BY THE
HURRICANE HUNTERS...MEASURED A PEAK WIND OF 109 KNOTS.  THE CURRENT
INTENSITY ESTIMATE IS ADJUSTED TO 90 KNOTS.  AN UPPER-LEVEL CYCLONE
SITUATED ABOUT 10 DEGREES TO THE WEST OF DENNIS SHOULD ASSIST THE
UPPER-LEVEL OUTFLOW AND SINCE THE OCEAN TEMPERATURES ARE QUITE
WARM...LARGE-SCALE FACTORS FAVOR STRENGTHENING.  HOWEVER...THE
LACK OF A WELL-DEFINED INNER CORE STRUCTURE IS A NEGATIVE FACTOR. 
THEREFORE ONLY A SLIGHT INCREASE IN INTENSITY IS PREDICTED AT THIS
TIME.  
 
PASCH 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     29/1500Z 30.4N  78.5W    90 KTS
12HR VT     30/0000Z 31.7N  78.5W    90 KTS
24HR VT     30/1200Z 33.0N  77.5W    95 KTS
36HR VT     31/0000Z 34.0N  76.0W   100 KTS
48HR VT     31/1200Z 34.7N  74.5W   100 KTS
72HR VT     01/1200Z 36.0N  72.0W   100 KTS
 
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