HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM COR
HURRICANE LENNY DISCUSSION NUMBER  19
NATIONAL WEATHER SERVICE MIAMI FL
10 PM EST WED NOV 17 1999

...CORRECTION PARAGRAPH 1...
 
THE LAST SEVERAL FIXES FROM U.S. AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT EARLIER THIS EVENING INDICATED THAT LENNY HAS BEEN DRIFTING
EAST-NORTHEASTWARD. IN FACT...THE HURRICANE HAS MOVED LITTLE DURING
THE LAST TWO HOURS.  THIS IS CONFIRMED BY NATIONAL WEATHER SERVICE
DOPPLER RADAR DATA OUT OF SAN JUAN PUERTO RICO. THE INITIAL MOTION
ESTIMATE IS QUASI-STATIONARY.
 
THE LATEST DATA RELAYED FROM THE RECON AIRCRAFT INDICATES THAT THE
MINIMUM CENTRAL PRESSURE IS NOW 939 MB...UP 5 MB OVER THE LAST
SEVERAL HOURS.  THE HIGHEST FLIGHT-LEVEL WINDS FOUND ON THE MOST
RECENT PASSES IS 128 KT.  THE INITIAL INTENSITY IS REDUCED TO 125 KT
FOR THIS ADVISORY.
 
ANALYSIS OF UPPER AIR DATA FROM THE NORTHEAST CARIBBEAN SHOWS THAT
LENNY IS IN A COL POINT BETWEEN THE TWO MID-TROPOSPHERIC HIGHS. A
SHORTWAVE TROUGH CURRENTLY MOVING THROUGH THE EASTERN/SOUTHEASTERN
U.S. IS EXPECTED TO MOVE EASTWARD INTO THE WESTERN ATLANTIC DURING
THE NEXT 12-24 HOURS.  THIS SHOULD HELP BUILD THE RIDGE TO THE EAST
OF THE HURRICANE AND ALLOW THE GENERAL NORTHEAST MOTION TO RESUME.
MOST OF THE OBJECTIVE TRACK AGREES ON A GENERAL NORTHEAST MOTION. 
THE OFFICIAL FORECAST IS VERY SIMILAR TO THE PREVIOUS ADVISORY BASED
ON THE TRACK UNCERTAINTY. 

THE INTENSITY FORECAST SHOWS GRADUAL WEAKENING THROUGH THE NEXT 
24 HOURS AS THE TROPICAL CYCLONE ENCOUNTERS AN INCREASING HOSTILE
UPPER-AIR ENVIRONMENT.  HOWEVER...IF LENNY STAYS QUASI-STATIONARY
LONG ENOUGH IT MAY WEAKEN MORE DURING THE NEXT 24 HOURS THAN
FORECAST.  

BECAUSE OF THE SIZE OF THE HURRICANE AND THE TRACK FORECAST
UNCERTAINTIES...ONE MUST NOT FOCUS ON THE EXACT FORECAST TRACK.
 
AS A RESULT OF THE QUASI-STATIONARY MOTION...TROPICAL STORM WARNING
HAVE BEEN RETAINED FOR EASTERN PORTIONS OF PUERTO RICO WHILE
HURRICANE WARNING REMAIN POSTED FOR CULEBRA AND VIEQUES...AND THE
U.S. AND BRITISH VIRGIN ISLANDS.
 
ANALYSES FROM THE HURRICANE RESEARCH DIVISION WERE USED TO ADJUST
THE WIND RADII.

GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     18/0300Z 17.7N  64.1W   125 KTS
12HR VT     18/1200Z 18.4N  63.4W   125 KTS
24HR VT     19/0000Z 19.4N  62.5W   115 KTS
36HR VT     19/1200Z 20.6N  61.4W   100 KTS
48HR VT     20/0000Z 22.0N  60.5W    85 KTS
72HR VT     21/0000Z 24.5N  59.0W    65 KTS

NNNN