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FORECASTS IMAGERY ABOUT TPC RECONNAISSANCE

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HURRICANE GERT DISCUSSION NUMBER  19
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT WED SEP 15 1999
 
THE SATELLITE PRESENTATION OF GERT IS NOT QUITE AS IMPRESSIVE THIS
EVENING AS IT WAS THIS AFTERNOON.  SATELLITE INTENSITY ESTIMATES AT
00Z WERE 127 AND 140 KT FROM TAFB AND SAB...BUT A RECENT 3 HR
AVERAGE OF THE RAW OBJECTIVE DVORAK NUMBERS FROM THE UNIVERSITY OF
WISCONSIN ALGORITHM WAS ABOUT 115 KT.  FOR CONTINUITY...THE OFFICIAL
INTENSITY IS HELD AT 130 KT FOR THIS PACKAGE.  THE TRUTH WILL BE
REVEALED LATER THIS MORNING WHEN A RECONNAISSANCE AIRCRAFT WILL BE
IN THE CYCLONE.  THE SHIPS INTENSITY FORECAST MODEL INDICATES SLIGHT
WEAKENING OVER THE NEXT THREE DAYS...BUT GERT IS EXPECTED TO REMAIN
A VERY POWERFUL HURRICANE. 

INITIAL MOTION IS 275/9...A BIT SLOWER THAN THE PREVIOUS ADVISORY. 
DROPSONDE DATA FROM THE NOAA GULFSTREAM JET NICELY SHOW THE MID-
LEVEL SUBTROPICAL RIDGE NORTH OF THE HURRICANE.  THE DATA ALSO SHOW
A BREAK IN THE RIDGE ALONG 60W...AND MOST OF THE GUIDANCE INDICATES
A TURN TO THE NORTHWEST BY THIS LONGITUDE.  THE 18Z AVIATION HAS A
HORRIBLE INITIALIZATION OF THE VORTEX REGION...WITH SOUTHEAST WINDS
A FEW HUNDRED MILES AHEAD OF THE HURRICANE AT 500 MB THAT ARE 40-50
KT IN ERROR.  THE OFFICIAL FORECAST IS IN CLOSE AGREEMENT WITH THE
UKMET WHICH HAS PERFORMED WELL WITH THIS SYSTEM.
 
FRANKLIN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     16/0300Z 17.9N  51.2W   130 KTS
12HR VT     16/1200Z 18.0N  52.5W   125 KTS
24HR VT     17/0000Z 18.4N  54.5W   120 KTS
36HR VT     17/1200Z 19.6N  56.6W   120 KTS
48HR VT     18/0000Z 21.0N  58.5W   115 KTS
72HR VT     19/0000Z 25.0N  61.0W   115 KTS
 
 
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