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HURRICANE LENNY DISCUSSION NUMBER   8
NATIONAL WEATHER SERVICE MIAMI FL
4 AM EST MON NOV 15 1999
 
LENNY IS STRENGTHENING RATHER QUICKLY THIS MORNING. REPORTS FROM AN
AIR FORCE RESERVE HURRICANE HUNTER INDICATE THE CENTRAL PRESSURE HAS
DROPPED TO 971 MB...WITH MAXIMUM 850 MB WINDS OF 100 KT. AN EYE
APPEARS INTERMITTENTLY ON INFRARED SATELLITE IMAGERY...AND SATELLITE
INTENSITY ESTIMATES FROM TAFB...SAB...AND AFWA ARE ALL 77 KT. BASED
ON THE AIRCRAFT DATA...THE MAXIMUM WINDS ARE RAISED TO 85 KT FOR
THIS PACKAGE. DESPITE THE INTENSIFICATION...THE WIND RADII REMAIN
RATHER SMALL.
 
LENNY MOVED EAST-SOUTHEAST DURING THE EVENING. HOWEVER...THE LATEST
SATELLITE IMAGERY INDICATES A MORE EASTWARD MOTION AND THE INITIAL
MOTION FOR THIS ADVISORY IS 095/8. A LARGE LONGWAVE TROUGH DOMINATES
THE WESTERN ATLANTIC...AND THIS SHOULD KEEP LENNY ON A GENERALLY
EASTWARD TRACK FOR THE NEXT 24 TO 36 HOURS. LARGE SCALE MODELS
SUGGESTS THAT A MID/UPPER LEVEL RIDGE WILL DEVELOP EAST OF THE
LESSER ANTILLES AFTER 36 HOURS...WHICH SHOULD TURN LENNY MORE TO THE
NORTHEAST. THE AMOUNT OF TURN...HOWEVER...IS UNCERTAIN. THE MEAN
POSITION OF THE LONGWAVE TROUGH IN THE MODELS IS ABOUT THE SAME
LONGITUDE AS THE HURRICANE...WHICH WOULD SUPPORT A MORE EASTWARD
MOTION. THIS IS SUPPORTED BY THE NOGAPS. ON THE OTHER HAND...MOST
OTHER GUIDANCE TURNS THE STORM MORE SHARPLY TO THE NORTHEAST. THE
OFFICIAL FORECAST IS A COMPROMISE BETWEEN THESE POSITIONS AND IS
ALONG THE RIGHT SIDE OF THE NHC HURRICANE GUIDANCE ENVELOPE.
 
AN UPPER LEVEL RIDGE OR ANTICYCLONE REMAINS OVER LENNY...SO FURTHER
INTENSIFICATION APPEARS LIKELY. THE BIGGEST QUESTION IS HOW LONG
WILL THE CURRENT RAPID STRENGTHENING CONTINUE? THE INTENSITY
FORECAST CALLS FOR FURTHER STRENGTHENING FOR 24 HOURS FOLLOWED BY A
LEVELING OUT. ALTHOUGH MAJOR NOVEMBER HURRICANES ARE NOT UNHEARD
OF...THEY ARE UNCOMMON ENOUGH THAT I WILL NOT FORECAST LENNY TO
BECOME ONE JUST YET.
 
BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     15/0900Z 15.4N  77.1W    85 KTS
12HR VT     15/1800Z 15.4N  76.0W    90 KTS
24HR VT     16/0600Z 15.6N  74.0W    95 KTS
36HR VT     16/1800Z 16.2N  71.8W    95 KTS
48HR VT     17/0600Z 17.0N  69.0W    95 KTS
72HR VT     18/0600Z 19.5N  63.5W    95 KTS
 
 
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