HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

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TROPICAL STORM DENNIS DISCUSSION NUMBER   5
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT TUE AUG 24 1999

SATELLITE PICTURES THIS EVENING SHOW THAT CIRCULATION OF DENNIS
REMAINS BROAD AND ILL-DEFINED. THE U.S. AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT IS CURRENTLY GATHERING DATA IN THE CYCLONE.  THE
LATEST VORTEX MESSAGE FROM THIS MISSION INDICATES THAT THE CENTER
IS A TAD SOUTH AND WEST OF THE LAST ADVISORY POSITION. THIS PLACES
THE CENTER WEST OF THE DEEP CONVECTION. HOWEVER...RECENT SATELLITE
IMAGERY SUGGESTS THE CENTER MAY BE RE-FORMING TO THE EAST OF THE
RECON POSITION. WITH THE CONTINUED UNCERTAINTY AND BROAD NATURE
OF THE SURFACE CIRCULATION THE INITIAL MOTION ESTIMATE IS 285/10 KTS
...WHICH IS BASED ON A 24-HR MEAN.  

ALL OF THE NUMERICAL MODELS ARE IN GOOD AGREEMENT ON THE EVOLUTION
OF A MID-TROPOSPHERIC TROUGH OVER THE EASTERN U.S. DURING THE NEXT
COUPLE OF DAYS. THIS WOULD RESULT IN A NORTHWEST MOTION FOLLOWED BY
A GRADUAL TURN TO THE NORTH BY LATE IN THE FORECAST PERIOD. MOST OF
THE TRACK GUIDANCE MODELS REFLECT THIS SCENARIO...AS DOES THE
OFFICIAL FORECAST.  THE NHC TRACK IS ON THE WESTERN SIDE OF THE
GUIDANCE AND IS IN GOOD AGREEMENT WITH THE LATEST GFDL OUTPUT. THIS
IS ALSO SLIGHTLY LEFT OF THE PREVIOUS ADVISORY MAINLY DUE TO THE
INITIAL MOTION/POSITION ESTIMATE. 

THE UPPER LEVEL OUTFLOW OVER DENNIS APPEARS WELL-ESTABLISHED.
ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SHOW LIGHT 
SHEAR CONDITIONS AND THE GLOBAL MODELS FORECAST AN UPPER LEVEL 
RIDGE OVER THE CYCLONE FOR THE NEXT SEVERAL DAYS. THE INTENSITY
FORECAST IS CONSISTENT WITH THE PREVIOUS PACKAGE AND CALLS FOR
GRADUAL STRENGTHENING.

THE OFFICIAL FORECAST MAKES THE NORTHWARD TURN CLOSE TO THE U.S.
SOUTHEAST COAST POSING A POTENTIAL THREAT TO GEORGIA AND THE
CAROLINAS. THEREFORE...RESIDENTS ALONG THE ENTIRE SOUTHEASTERN
UNITED STATES COAST SHOULD CLOSELY MONITOR THE PROGRESS OF THIS
SYSTEM.

GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     25/0300Z 22.9N  71.9W    40 KTS
12HR VT     25/1200Z 23.4N  73.0W    50 KTS
24HR VT     26/0000Z 24.3N  74.4W    60 KTS
36HR VT     26/1200Z 25.9N  75.9W    70 KTS
48HR VT     27/0000Z 27.5N  77.0W    80 KTS
72HR VT     28/0000Z 30.5N  77.5W    90 KTS
 
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