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TROPICAL STORM KAREN DISCUSSION NUMBER   3
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT SAT OCT 13 2001
 
EARLY MORNING SATELLITE IMAGERY SHOWS A MARKED INCREASE IN
CONVECTION NEAR THE CENTER OF SUBTROPICAL STORM ONE....WITH TOPS 
COLDER THAN -60C PRESENT FOR THE LAST SEVERAL HOURS.  DVORAK
TROPICAL CYCLONE INTENSITY ESTIMATES ARE NOW EQUAL TO THE HEBERT- 
POTEAT SUBTROPICAL INTENSITY ESTIMATES.  ON THIS BASIS...THE
SUBTROPICAL STORM IS UPGRADED TO TROPICAL STORM KAREN.  THE 
MAXIMUM SUSTAINED WINDS WIL REMAIN AT 55 KT IN AGREEMENT WITH
THE SATELLITE ESTIMATES.
 
THE INITIAL MOTION IS NOW 035/8.  KAREN IS IN AN AREA OF DEEP-LAYER
SOUTHWEST TO SOUTH-SOUTHWEST FLOW BETWEEN A RIDGE OVER THE CENTRAL
ATLANTIC AND STRONGER FLOW ASSOCIATED WITH STRONG TROUGHING OVER THE
UNITED STATES.  THEREFORE...KAREN SHOULD CONTINUE ON A GENERAL
NORTH-NORTHEAST TO NORTHEAST TRACK WITHOUT A LOT OF ACCELERATION.
NHC HURRICANE GUIDANCE GENERALLY AGREES WITH THIS SCENARIO...WITH
ABOUT A NORMAL SPREAD IN DIRECTION AND SPEED.  THE TRACK FORECAST
IS BASICALLY AN UPDATE OF THE PREVIOUS FORECAST...ADJUSTED SOMEWHAT
TO THE EAST TO ALLOW FOR THE NEW INITIAL POSITION.
 
KAREN IS OVER 25C WATER AND SHOULD REMAIN OVER SIMILAR SEA SURFACE
TEMPERATURES UNTIL IT CROSSES THE GULF STREAM.  INTENSITY FORECAST
GUIDANCE CALLS FOR LITTLE CHANGE IN STRENGTH WHILE THE CYCLONE IS
OVER WARM WATER...FOLLOWED BY WEAKENING OVER THE COLDER WATER NORTH
OF THE GULF STREAM.  THE INTENSITY FORECAST WILL FOLLOW THE
GUIDANCE.  THERE IS A CHANCE THAT KAREN COULD REACH HURRICANE
STRENGTH IF THE CONVECTION WRAPS AROUND THE FORMER CLEAR CENTER TO
FORM A TRUE EYE.
 
FORECASTER BEVEN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     13/0900Z 35.2N  65.0W    55 KTS
12HR VT     13/1800Z 36.3N  64.4W    55 KTS
24HR VT     14/0600Z 37.8N  63.6W    55 KTS
36HR VT     14/1800Z 39.6N  62.5W    50 KTS
48HR VT     15/0600Z 41.5N  60.8W    40 KTS
72HR VT     16/0600Z 44.5N  58.5W    30 KTS...EXTRATROPICAL
 
 
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