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HURRICANE GERT DISCUSSION NUMBER  34
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT SUN SEP 19 1999

ALTHOUGH ALL OF THE TRACK GUIDANCE MODELS KEEP THE CENTER OF THE
HURRICANE EAST OF BERMUDA...SEVERAL FACTORS DICTATE THE ISSUANCE OF
A HURRICANE WATCH AND TROPICAL STORM WARNING FOR THE ISLANDS AT THIS
TIME.  THESE INCLUDE: (A) UNCERTAINTIES IN THE FORECAST...(B) THE
SIZE AND STRENGTH OF GERT...(C) AN INCREASE IN FORWARD SPEED...AND
(D) AVOIDING THE ISSUANCE OF WATCHES AND WARNINGS LATE AT NIGHT.

MOTION IS ALONG THE SAME HEADING WITH SOME INCREASE IN SPEED...
320/10.  THE TRACK FORECAST REASONING IS ABOUT THE SAME AS BEFORE. 
GERT IS CURRENTLY MOVING THROUGH A WEAKNESS IN THE SUBTROPICAL
RIDGE.  DURING THE NEXT DAY OR TWO...A LARGE 500 MB TROUGH NEAR 
THE EASTERN U.S. COAST IS EXPECTED TO TURN THE HURRICANE MORE
NORTHWARD.  HOWEVER THE TURN COULD BE DELAYED AND GERT COULD
COME DANGEROUSLY CLOSE TO BERMUDA. 

MICROWAVE DATA INDICATE THAT GERT UNDERWENT AN EYEWALL REPLACEMENT
CYCLE EARLIER TODAY...AND THIS MAY HAVE EXPLAINED WHY IT APPEARED
WEAKER AT THAT TIME.  THE INTENSITY FORECAST REMAINS THE SAME AS
BEFORE...AND MAINTAINS MAJOR HURRICANE STATUS FOR THE NEXT FEW DAYS.

LATE IN THE PERIOD...GERT MAY WEAKEN A LITTLE MORE THAN SHOWN HERE
...DUE TO A LESS FAVORABLE ENVIRONMENT.
 
PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     19/2100Z 25.9N  60.4W   115 KTS
12HR VT     20/0600Z 27.0N  61.5W   115 KTS
24HR VT     20/1800Z 28.5N  63.0W   115 KTS
36HR VT     21/0600Z 30.5N  63.0W   110 KTS
48HR VT     21/1800Z 32.5N  62.5W   105 KTS
72HR VT     22/1800Z 37.0N  61.0W   100 KTS
  
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