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TROPICAL DEPRESSION SEVENTEEN DISCUSSION NUMBER   1
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT MON OCT 16 2000
 
THE LOW PRESSURE CENTER BETWEEN BERMUDA AND THE NORTHERN BAHAMAS HAS
GRADUALLY BEEN ACQUIRING TROPICAL CHARACTERISTICS OVER THE PAST 24
HOURS.  AN AMSU PASS THIS MORNING...COURTESY OF THE UW/CIMSS WEB
PAGE...SHOWED THE BEGINNINGS OF A WARM CORE ALOFT.  RECENT INFRARED
IMAGERY SHOWS THE DEVELOPMENT OF ANTICYCLONIC OUTFLOW TO THE WEST
AND NORTH OF THE CENTER...AND THE CIRCULATION APPEARS TO HAVE
CONTRACTED AS WELL.  WHILE THE CONVECTION NEAR THE CENTER IS NOT
DEEP...IT IS WELL ORGANIZED...AND THE LOW CLEARLY NOW MEETS THE
CRITERIA FOR A TROPICAL CYCLONE.  THE SATELLITE INTENSITY ESTIMATE
FROM TAFB USING THE TROPICAL CLASSIFICATION IS 30 KT...AND IS THE
BASIS FOR THE ADVISORY INTENSITY VALUE.  A QUIKSCAT PASS NEAR 23Z
HAD ONE RAIN-FREE VECTOR OF 35 KT...SO THE DEPRESSION IS PROBABLY
VERY CLOSE TO TROPICAL STORM STRENGTH.  AN AIR FORCE RECONNAISSANCE
AIRCRAFT WILL BE IN THE DEPRESSION TOMORROW AFTERNOON TO PROVIDE
SOME DIRECT INTENSITY DATA.
 
THERE HAS BEEN A SLOW EAST OR NORTHEASTWARD DRIFT DURING THE DAY
TODAY.  THE DEPRESSION IS IN A WEAK STEERING FLOW...CURRENTLY CUTOFF
FROM THE WESTERLIES TO THE NORTH...AND IN BETWEEN TWO MID-LEVEL
RIDGES TO THE EAST AND WEST OF THE CYCLONE.  GLOBAL MODELS INDICATE
THAT THE RIDGE TO THE WEST WILL GRADUALLY ERODE OVER THE NEXT DAY OR
TWO AS A SHORT-WAVE TROUGH AMPLIFIES AND MOVES OFF THE NORTHEAST
U.S. COAST IN ABOUT 48 HOURS.  THIS SCENARIO CALLS FOR LITTLE MOTION
FOR THE NEXT 24 HOURS OR SO FOLLOWED BY AN ACCELERATION TO THE NORTH
THEN NORTHEAST.  THE OFFICIAL FORECAST IS BETWEEN THE GFDL AND THE
MEDIUM LAYER BAM.
 
ALTHOUGH OUTFLOW HAS BEEN IMPROVING...THE DEPRESSION IS EMBEDDED
WITHIN AN UPPER LEVEL LOW THAT DOES NOT SEEM CONDUCIVE TO RAPID
STRENGTHENING.  WITHIN 36 TO 48 HOURS THE SHEAR AHEAD OF THE
APPROACHING TROUGH WOULD ALSO NOT BE EXPECTED TO BE FAVORABLE.  ONLY
MODEST STRENGTHENING IS INDICATED BY THE OFFICIAL FORECAST WHICH IS
IN GOOD AGREEMENT WITH THE SHIPS INTENSITY GUIDANCE.
 
FORECASTER FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     17/0300Z 29.8N  70.9W    30 KTS
12HR VT     17/1200Z 30.3N  70.5W    30 KTS
24HR VT     18/0000Z 30.8N  70.4W    35 KTS
36HR VT     18/1200Z 32.0N  70.3W    40 KTS
48HR VT     19/0000Z 34.5N  69.0W    40 KTS
72HR VT     20/0000Z 44.0N  58.0W    40 KTS...EXTRATROPICAL
 
 
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