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TROPICAL STORM FRANCES DISCUSSION NUMBER   9
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT THU SEP 10 1998
 
THE STORM CONTINUES TO EXHIBIT A BROAD CENTRAL AREA OF ABOUT EQUAL
PRESSURE...LIGHT WINDS...AND SMALLER-SCALE VORTICES EVIDENT ON HIGH-
RES VISIBLE IMAGERY.  AS SUCH IT IS DIFFICULT TO LOCATE A UNIQUE
CENTER.  BUT...AS MENTIONED EARLIER...THE STORM HAS BECOME A LITTLE
BETTER-ORGANIZED AS COMPARED TO YESTERDAY.  MAXIMUM SUSTAINED
SURFACE WINDS ARE NOW ESTIMATED TO BE NEAR 50 KNOTS...WELL NORTHEAST
OF THE CENTER.  RECENTLY...AN OIL RIG NEAR 28N92W REPORTED SUSTAINED
WINDS OF 68 KNOTS WITH GUSTS TO 77 KNOTS MORE THAN 100 FEET ABOVE
SEA LEVEL.  THERE IS AN IMPRESSIVE UPPER-TROPOSPHERIC ANTICYCLONE
OVER THE SYSTEM AND THE UNIVERSITY OF WISCONSIN CIMSS ANALYSES SHOW
LOW VERTICAL SHEAR OVER THE AREA.  FURTHER STRENGTHENING COULD OCCUR
BEFORE LANDFALL.
 
EVEN THOUGH THERE HAVE BEEN SEVERAL CENTER SHIFTS OR REFORMATIONS TO
THE NORTH...MODEL GUIDANCE INDICATES A MORE WEST-NORTHWESTWARD TO
NORTHWESTWARD MOTION.  THE LATEST NCEP GLOBAL MODEL RUN SHOWS A 500
MB HIGH PERSISTING NEAR AND TO NORTHEAST OF TEXAS...PROVIDING A WEAK
EAST TO SOUTHEASTERLY STEERING CURRENT.  THIS SHOULD ALLOW FRANCES
TO MOVE INLAND SLOWLY OVER SOUTHERN TEXAS WITHIN IN A DAY OR SO.
 
TROPICAL STORM WARNINGS WERE EXTENDED TO INCLUDE THE LOUISIANA COAST
BECAUSE OF THE STRONG PRESSURE GRADIENT IN THAT AREA.  IF THE
STRENGTHENING TREND CONTINUES...A HURRICANE WARNING MAY BE REQUIRED
LATER TONIGHT OR EARLY FRIDAY.
 
PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     10/2100Z 26.5N  95.2W    50 KTS
12HR VT     11/0600Z 27.0N  96.1W    50 KTS
24HR VT     11/1800Z 27.6N  97.0W    60 KTS
36HR VT     12/0600Z 28.0N  98.0W    40 KTS...INLAND
48HR VT     12/1800Z 28.5N  99.0W    25 KTS...INLAND
72HR VT     13/1800Z 29.5N 100.5W    20 KTS...INLAND
 
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