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TROPICAL STORM GERT DISCUSSION NUMBER   7
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT SUN SEP 12 1999

GERT REMAINS WELL-ORGANIZED...HOWEVER DVORAK CLASSIFICATIONS FROM
TAFB MIAMI AND SAB WASHINGTON DO NOT YET JUSTIFY UPGRADING IT TO A
HURRICANE.  THE STORM IS CURRENTLY OVER 27 DEG C SSTS AND WILL BE 
PASSING OVER PROGRESSIVELY WARMER WATERS DURING THE FORECAST PERIOD.
UPPER-LEVEL OUTFLOW IS WELL-ESTABLISHED OVER ALL BUT THE EASTERN
QUADRANT.  CURRENT INTENSITY IS SET AT 60 KNOTS AND STRENGTHENING IS
PREDICTED...AS IN THE PREVIOUS PACKAGE.  THIS IS ALSO IN REASONABLE
AGREEMENT WITH THE STATISTICAL INTENSITY PREDICTION SCHEME...SHIPS.

BASED ON RECENT CENTER FIXES...THE MOTION CONTINUES TOWARD THE WEST
AT JUST A SLIGHTLY SLOWER FORWARD SPEED...17 KNOTS.  THE TRACK
FORECAST PHILOSOPHY IS ESSENTIALLY UNCHANGED.  A MID-TROPOSPHERIC
RIDGE IS LIKELY TO PERSIST TO THE NORTH OF GERT FOR THE NEXT FEW
DAYS...AND THIS SUPPORTS A CONTINUATION OF A SLIGHTLY NORTH OF
WESTWARD MOTION FOR THE NEXT COUPLE OF DAYS.  IN THE LATTER PART OF
THE FORECAST PERIOD...THE GFDL AND GLOBAL MODEL GUIDANCE  SUGGESTS A
MORE NORTHWESTWARD MOTION AND SOME SLOWING.  THE OFFICIAL FORECAST
IS VERY CLOSE TO THE LBAR MODEL WHICH...WITH ITS BAROTROPIC
DYNAMICS...SHOULD HANDLE SYSTEMS IN THE DEEP TROPICS QUITE WELL. 

PASCH

FORECAST POSITIONS AND MAX WINDS
 
INITIAL     13/0300Z 15.1N  36.3W    60 KTS
12HR VT     13/1200Z 15.3N  39.0W    65 KTS
24HR VT     14/0000Z 15.7N  42.0W    75 KTS
36HR VT     14/1200Z 16.0N  45.0W    85 KTS
48HR VT     15/0000Z 16.5N  48.0W    90 KTS
72HR VT     16/0000Z 17.0N  53.0W    95 KTS
 
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