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TROPICAL STORM FLOYD DISCUSSION NUMBER   7
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT THU SEP 09 1999

ON THEIR FIRST MISSION INTO FLOYD...THE AIR FORCE HURRICANE HUNTERS
FOUND THAT THE STORM IS PRETTY MUCH ON TRACK...BUT THAT THE PREVIOUS
INTENSITY ESTIMATES WERE A BIT ON THE HIGH SIDE.  ON TWO DROPS INTO
THE EYE...THE HURRICANE HUNTERS MEASURED 1002 AND 1003 MB.  SURFACE
WIND MEASUREMENTS AT THE DROPWINSONDE SPLASH POINTS SUGGEST THAT
NEITHER DROP WAS QUITE AT THE SURFACE CENTER POSITION HOWEVER. 
ALTHOUGH THE FLIGHT-LEVEL WINDS DO NOT SUPPORT AS STRONG A STORM AS
WE THOUGHT...FOR THE SAKE OF CONTINUITY...THE CURRENT INTENSITY IS
KEPT AT 50 KNOTS FOR THIS ADVISORY.  ON THE LARGE SCALE...THE CLOUD
PATTERN CONTINUES TO LOOK VERY IMPRESSIVE WITH STRONG UPPER-LEVEL
OUTFLOW EVIDENT.  RECENT GOES-8 IMAGES AFTER THE SATELLITE ECLIPSE
SHOW THE CONVECTION CONSOLIDATING AND INTENSIFYING OVER THE
CENTER... SUGGESTING THAT THE INNER CORE MAY BE GETTING BETTER
ORGANIZED.  IF THIS IS THE CASE...THEN STRENGTHENING AT A MORE RAPID
RATE MAY COMMENCE SOON.

INITIAL MOTION...285/13 IS ABOUT THE SAME AS BEFORE.  A SLIGHT
NORTHWARD ADJUSTMENT IS MADE TO THE PREVIOUS FORECAST TRACK...BUT
THE PROGNOSTIC REASONING IS ESSENTIALLY THE SAME.  THE MID-
TROPOSPHERIC RIDGE TO THE NORTH OF THE STORM IS PREDICTED TO
GRADUALLY WEAKEN WITH TIME...THUS THE NHC FORECAST SHOWS SOME
SLOWING OF FORWARD SPEED AND A GRADUAL TURN TOWARD THE NORTHWEST.   
THIS IS SUPPORTED BY THE OBJECTIVE TRACK PREDICTIONS AS WELL...AND
KEEPS FLOYD TO THE NORTH OF THE LEEWARD ISLANDS.  HOWEVER...IF THE
STORM DOES NOT TURN MORE TOWARD THE NORTHWEST...A PORTION OF FLOYDS
LARGE CIRCULATION COULD AFFECT THE NORTHERNMOST OF THESE ISLANDS. 
INTERESTS IN THE NORTHERN LEEWARD SHOULD CONTINUE TO MONITOR THE
PROGRESS OF THIS SYSTEM.

THE EVOLUTION OF THE MID-TROPOSPHERIC FLOW OVER THE EASTERN U.S.
DURING THE NEXT 3 TO 5 DAYS IS CRITICAL FOR THE LONGER-RANGE TRACK
OF FLOYD.  IF THE TROUGH OVER THE EASTERN STATES LIFTS OUT LATER
THIS WEEKEND...THEN THE TROPICAL CYCLONE MAY NOT IMMEDIATELY
RECURVE...OR EVEN TURN BACK TOWARD THE WEST-NORTHWEST OR WEST. 
THERE IS SOME SUGGESTION OF THIS IN THE LATEST RUNS OF THE GFDL AND
AVN MODELS.  AT THIS JUNCTURE...THIS SHOULD BE CONSIDERED
SPECULATION.

PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     09/0900Z 17.3N  54.6W    50 KTS
12HR VT     09/1800Z 17.9N  56.4W    60 KTS
24HR VT     10/0600Z 19.1N  58.6W    70 KTS
36HR VT     10/1800Z 20.5N  60.5W    80 KTS
48HR VT     11/0600Z 21.5N  62.0W    90 KTS
72HR VT     12/0600Z 23.5N  64.5W    95 KTS
 
 
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