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HURRICANE FLOYD DISCUSSION NUMBER  27
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT TUE SEP 14 1999
 
RECENT FIXES FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
INDICATE THAT THE ANTICIPATED WEST-NORTHWEST MOTION HAS BEGUN...
AND THE INITIAL MOTION ESTIMATE IS NOW 290/12 KTS.  SATELLITE
IMAGERY SHOWS A NNW-SSE ELONGATION OF THE STORM ENVELOPE INDICATING
THAT FLOYD IS BEGINNING TO FEEL THE EFFECTS OF THE APPROACHING MID-
UPPER LEVEL TROPOSPHERIC TROUGH. THE TRACK FORECAST REASONING
REMAINS UNCHANGED AS THE MID TO UPPER-LEVEL TROUGH APPROACHING THE
EASTERN U.S. WILL LIKELY ERODE THE WESTERN PERIPHERY OF THE HIGH
WHICH HAS BEEN STEERING FLOYD WESTWARD.  THIS SHOULD CREATE MORE 
OF A NORTHWARD STEERING CURRENT...AND FLOYD IS EXPECTED TO TURN
NORTHWESTWARD DURING THE NEXT 12 TO 24 HOURS FOLLOWED BY A NORTHWARD
HEADING THROUGH 48 HRS.  MOST OF THE GUIDANCE MODELS ARE IN GOOD
AGREEMENT WITH THIS SCENARIO...AND IS REFLECTED IN THE OFFICIAL
FORECAST. THE NHC TRACK IS VERY SIMILAR TO THE PREVIOUS ADVISORY.

THE LATEST MINIMUM CENTRAL PRESSURE FROM THE RECONNAISSANCE AIRCRAFT
IS 928 MB...A 5 MB RISE OVER THE LAST 24 HRS. THE MAXIMUM FLIGHT-
LEVEL WINDS WERE 119 KTS WHILE THE GPS DROPSONDE RECORDED A MAXIMUM
OF 133 KTS.  RECON DATA SHOWS A DOUBLE WIND MAX STRUCTURE SUGGESTING
THAT A CONCENTRIC EYEWALL CYCLE MAY BE UNDERWAY.  THE INITIAL
INTENSITY WILL BE HELD AT 135 KTS.  SATELLITE IMAGERY SHOWS THAT
THE HURRICANE REMAINS VERY SYMMETRIC AND GOOD OUTFLOW PERSISTS IN
ALL BUT THE SOUTHWEST QUADRANT. ALTHOUGH SOME FLUCTUATIONS IN
INTENSITY ARE LIKELY...LITTLE CHANGE IN STRENGTH IS EXPECTED DURING
THE NEXT DAY OR SO.  THEREAFTER...THE NCEP GLOBAL MODELS ALONG WITH
THE NAVY NOGAPS MODEL INDICATE THAT THE UPPER LEVEL ANTICYCLONE WILL
MOVE EAST RESULTING IN SOUTHWESTERLY VERTICAL WIND SHEAR OVER FLOYD
WHICH SHOULD GRADUALLY WEAKEN THE HURRICANE.  THIS IS CONSISTENT
WITH THE LAST FORECAST PACKAGE AND THE SHIPS INTENSITY SCHEME...
ALTHOUGH NOT AS DRAMATIC.   

AFTER CONSULTATION WITH THE GOVERNMENT OF THE BAHAMAS...THE TROPICAL
STORM WARNING FOR THE TURKS AND CAICOS ISLANDS IS DISCONTINUED.  THE
WARNING FOR THE SOUTHEASTERN BAHAMAS WILL LIKELY BE LOWERED LATER
THIS MORNING.

REGARDLESS OF THE WEST-NORTHWEST MOTION...HURRICANE FLOYD WILL STILL
COME DANGEROUSLY CLOSE TO THE EAST FLORIDA COAST.  ALL PREPARATIONS
SHOULD BE RUSHED TO COMPLETION IN THE WARNING AREA. 

GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     14/0900Z 25.1N  75.9W   135 KTS
12HR VT     14/1800Z 26.1N  77.5W   135 KTS
24HR VT     15/0600Z 27.6N  79.3W   130 KTS
36HR VT     15/1800Z 29.7N  80.5W   125 KTS
48HR VT     16/0600Z 32.5N  80.5W   120 KTS
72HR VT     17/0600Z 40.0N  78.5W    50 KTS...INLAND
 
 
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