HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

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TROPICAL DEPRESSION ELEVEN DISCUSSION NUMBER   7
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT WED OCT 06 1999
 
THE LATEST DATA RELAYED FROM THE AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT INDICATES THAT THE CENTER IS SLIGHTLY SOUTH OF THE LAST FEW
FIXES BUT ESSENTIALLY HAS BEEN MEANDERING THE LAST 6 HOURS OR SO.
IN FACT THE LAST MESSAGE RECEIVED FROM THE AIRCRAFT STATED THAT THEY
WERE HAVING A HARD TIME FINDING A CLOSED CIRCULATION CENTER. THE
INITIAL MOTION ESTIMATE FOR THIS PACKAGE IS STATIONARY. 

THE FORECAST TRACK GUIDANCE REMAINS QUITE SCATTERED WITH THE GFDN
AND NOGAPS MEANDERING THE DEPRESSION.  MEANWHILE...THE AVN DRIFTS 
IT NORTHWARD. THE PHILOSOPHY BEHIND THE TRACK FORECAST REMAINS
UNCHANGED WITH THE EXPECTED EASTWARD SHIFT OF THE MID-TROPOSPHERIC 
RIDGE NORTH OF THE DEPRESSION ALLOWING A MORE NORTH-NORTHWEST TO
NORTH MOTION BEYOND 36 HOURS.  THE OFFICIAL FORECAST IS AN UPDATE 
OF THE PREVIOUS ADVISORY WHICH CALLS FOR LITTLE MOTION DURING THE
NEXT DAY OR SO FOLLOWED BY A SLOW GENERAL NORTHWARD TRACK.  HOWEVER
...THE SYSTEM MAY NOT LAST THAT LONG.
 
AS HAS BEEN THE CASE FOR MOST OF ITS EXISTENCE...THE DEPRESSION IS
VERY DIFFICULT TO IDENTIFY IN SATELLITE IMAGERY WITH A CHAOTIC
CONVECTIVE PATTERN UNCHARACTERISTIC OF A DEVELOPING TROPICAL
CYCLONE. THE INITIAL INTENSITY WILL BE HELD AT 30 KNOTS.  THE
RECONNAISSANCE REPORTED A MINIMUM CENTRAL PRESSURE OF 1007 MB...
UP 3 MB FROM LATE YESTERDAY AFTERNOON.  AS MENTIONED IN THE LAST
ADVISORY...ITS HARD TO FORECAST STRENGTHENING GIVEN THE CURRENT
CLOUD PATTERN AND THE SYSTEMS PROXIMITY TO LAND. THE 00Z NCEP GLOBAL
MODEL DEVELOPS AN UPPER-LEVEL ANTICYCLONE OVER THE WESTERN GULF OF
MEXICO BETWEEN 24 AND 48 HRS. THUS...FURTHER INTENSIFICATION WILL
ONLY OCCUR IF THE DEPRESSION SURVIVES THE NEXT 24 TO 36 HOURS AND
MOVES AWAY FROM LAND.  

VERY COLD CLOUD TOPS...TO -80C...PERSIST ALONG THE EASTERN PORTION
OF MEXICO BETWEEN TAMPICO AND VERACRUZ.  THE PRIMARY THREAT THIS
SYSTEM POSES IS ONE OF HEAVY RAINS...AND THE COLLATERAL THREAT OF
FLASH FLOODS AND MUDSLIDES ESPECIALLY IN MOUNTAINOUS TERRAIN.  

GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     06/0900Z 19.5N  95.0W    30 KTS
12HR VT     06/1800Z 19.7N  95.2W    30 KTS
24HR VT     07/0600Z 20.2N  95.5W    30 KTS
36HR VT     07/1800Z 20.5N  95.7W    30 KTS
48HR VT     08/0600Z 21.5N  96.0W    35 KTS
72HR VT     09/0600Z 23.5N  96.0W    40 KTS
 
 
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