HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

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HURRICANE GERT DISCUSSION NUMBER  30
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT SAT SEP 18 1999
 
GERT CONTINUES TO BE WELL ORGANIZED WITH BANDING FEATURES AND A
LARGE EYE.  THE RING OF CONVECTION SURROUNDING THE EYE ONCE AGAIN
INCREASED...CONSEQUENTLY DVORAK T-NUMBERS ARE UP A LITTLE BIT. THESE
UP AND DOWN FLUCTUATIONS ARE LIKELY TO CONTINUE. THEREFORE THE
AVERAGE INTENSITY WILL BE SET AT 105 KNOTS THROUGH 72 HOURS. GERT
MAY RE- STRENGTHEN...IF THERE IS TROUGH INTERACTION LATER IN THE
PERIOD.  SHIPS SHOWS NO SIGNIFICANT CHANGE IN INTENSITY.
 
INITIAL MOTION IS 320/08. THE HURRICANE IS MOVING AROUND THE
PERIPHERY OF THE SUBTROPICAL RIDGE WHICH IS FORECAST TO PERSIST OVER
THE EASTERN ATLANTIC.  HOWEVER...A VERY STRONG UPPER TROUGH...AND A
COLD FRONT ARE FORECAST TO SWEEP EASTWARD OVER THE EASTERN UNITED
STATES DURING THE NEXT FEW DAYS.  THIS TROUGH APPEARS TO BE STRONG
ENOUGH TO KEEP GERT OVER THE OPEN ATLANTIC BUT DANGEROUSLY CLOSE TO
BERMUDA.  THIS IS CONSISTENT WHICH TRACK GUIDANCE.
 
INTERESTS IN BERMUDA SHOULD CONTINUE TO MONITOR THE PROGRESS OF
GERT.

THE 50- AND 34- KNOT WIND RADII HAVE BEEN EXPANDED ON THE EASTERN
SEMICIRCLE BASED ON OBSERVATIONS FROM SHIPS C6B09 AND ELSL9 WHICH
REPORTED 55 AND 50 KNOTS RESPECTIVELY...WELL EAST OF THE EYE.
 
AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     18/2100Z 23.2N  58.1W   105 KTS
12HR VT     19/0600Z 24.2N  59.0W   105 KTS
24HR VT     19/1800Z 25.5N  60.0W   105 KTS
36HR VT     20/0600Z 26.5N  61.0W   105 KTS
48HR VT     20/1800Z 27.5N  62.0W   105 KTS
72HR VT     21/1800Z 30.0N  63.5W   105 KTS
 
 
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