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HURRICANE FLOYD DISCUSSION NUMBER  12
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT FRI SEP 10 1999

AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT REPORTED FLIGHT-
LEVEL WINDS OF 88 KT THIS MORNING.  THIS SUPPORTS A SURFACE WIND
ESTIMATE OF 70 KT AND FLOYD IS NOW A HURRICANE.  WIND RADII HAVE
BEEN ADJUSTED BASED ON A SURFACE WIND ANALYSIS PROVIDED BY THE NOAA
HURRICANE RESEARCH DIVISION.  THEIR ANALYSIS ALSO INDICATES A 
MAXIMUM SURFACE WIND OF ABOUT 70 KT.

FLOYD CONTINUES TO HAVE SOME DIFFICULTY CONSOLIDATING ITS INNER
CORE...AND THE LOW-LEVEL CENTER OF CIRCULATION IS STILL NOT QUITE
CO-LOCATED WITH THE CONVECTION OR MID-LEVEL ROTATION.  THE MOST
RECENT MSLP WAS 989 MB...UP A BIT FROM EARLIER.  THIS PROBABLY
REFLECTS THE POOR INNER ORGANIZATION RATHER THAN A WEAKENING TREND. 
UPPER-LEVEL OUTFLOW REMAINS IMPRESSIVE...IF A BIT RESTRICTED ON THE
NORTHWEST SIDE.  THE SHIPS AND GFDL INTENSITY GUIDANCE BRINGS FLOYD
TO CLOSE TO MAJOR HURRICANE STATUS IN THREE DAYS.  THE AVN DEVELOPS
AN UPPER-LEVEL ANTICYCLONE NORTH OF FLOYD DURING THE FORECAST PERIOD
THAT SHOULD PROVIDE A LONGER TERM ENVIRONMENT CONDUCIVE FOR
STRENGTHENING.

THE INITIAL MOTION IS 295/9.  A SYNOPTIC SURVEILLANCE MISSION BY THE
NOAA JET LAST NIGHT SHOWS A SLIGHT WEAKNESS IN THE 500 MB RIDGE TO
THE NORTH OF FLOYD AND THIS HAS LIKELY CONTRIBUTED TO THE DECREASE
IN FORWARD SPEED COMPARED TO YESTERDAY.  THE NCEP CLOBAL MODEL AT
06Z CONTINUES TO ANALYZE AN UNREALISTIC-LOOKING RING OF VORTICITY
SURROUNDING FLOYD...WHICH APPEARS TO INDUCE A NORTHWARD TRACK
DEFLECTION IN THE MODEL FORECAST IN THE SHORT TERM.  THIS IS
DISCOUNTED IN THE OFFICIAL FORECAST WHICH CALLS FOR A WEST-NORTHWEST
TRACK FOR 48 HOURS.  BEYOND THAT...THE MID-TROPOSPHERIC TROUGH OVER
THE EASTERN U.S. IS FORECAST TO LIFT OUT...LEAVING A CUTOFF LOW IN
THE EASTERN GULF OF MEXICO AND STRONG RIDGING NORTH OF THE CYCLONE. 
IF THIS SCENARIO VERIFIES...A MORE WESTWARD TRACK IS LIKELY AT 72
HOURS.  THE OFFICIAL FORECAST IS VERY SIMILAR TO THE PREVIOUS
ADVISORY AND IN CLOSE AGREEMENT WITH THE UKMET AND LBAR.

FRANKLIN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     10/1500Z 19.3N  59.2W    70 KTS
12HR VT     11/0000Z 19.9N  60.5W    80 KTS
24HR VT     11/1200Z 20.8N  62.0W    85 KTS
36HR VT     12/0000Z 21.9N  63.9W    90 KTS
48HR VT     12/1200Z 23.0N  66.0W    95 KTS
72HR VT     13/1200Z 24.0N  69.5W   105 KTS
 
 
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