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HURRICANE GERT DISCUSSION NUMBER  17
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT WED SEP 15 1999

GERT CLOUD PATTERN CONTINUES TO IMPROVE. THE EYE IS MORE DEFINED AND
DISTINCT ON IMAGES AND IS SURROUNDED BY A RING OF DEEP CONVECTION
WITH TOPS BETWEEN -70 AND 75 DEGREES CELSIUS.  OBJECTIVE AND
SUBJECTIVE NUMBERS ARE UP TO 6.0 ON THE DVORAK SCALE. BASED ON THIS
DATA...WINDS ARE INCREASED TO 115 KNOTS.  THIS MAKES GERT THE FOURTH
CATEGORY FOUR HURRICANE ON THE SAFFIR SIMPSON-SCALE OF THE SEASON.
SOME FLUCTUATIONS IN INTENSITY ARE EXPECTED DURING HE NEXT 3 DAYS.

INITIAL MOTION IS 275/11. THE HURRICANE IS MOVING WESTWARD AROUND
THE PERIPHERY OF A STRONG SUBTROPICAL RIDGE.  HOWEVER...AS THE
HURRICANE MOVES WESTWARD...IT WILL ENCOUNTER A WEAKENING OF THE
RIDGE...ERODED BY HURRICANE FLOYD AND ANOTHER DISTURBANCE. A GRADUAL
TURN TO THE NORTHWEST IS THEN INDICATED AS THE HURRICANE APPROACHES
55W. THIS TRACK WOULD BRING THE HURRICANE WELL NORTH TO THE LEEWARD
ISLANDS.

NOTE: A DRIFTING BUOY LOCATED ON THE WESTERN EYEWALL OF GERT
REPORTED NORTH WINDS OF 97 KNOTS.  THIS REPORT HAS YET TO BE
CONFIRMED.

AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     15/1500Z 17.6N  49.5W   115 KTS
12HR VT     16/0000Z 17.7N  51.1W   115 KTS
24HR VT     16/1200Z 18.5N  53.5W   115 KTS
36HR VT     17/0000Z 19.5N  55.5W   115 KTS
48HR VT     17/1200Z 20.5N  57.5W   115 KTS
72HR VT     18/1200Z 23.5N  60.5W   115 KTS
 
 
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