HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION KATRINA DISCUSSION NUMBER  13
NATIONAL WEATHER SERVICE MIAMI FL
4 PM EST SUN OCT 31 1999
 
VISIBLE SATELLITE PICTURES SHOW THAT THE CENTER OF KATRINA HAS
BECOME A LITTLE BETTER DEFINED DURING THE DAY. SURFACE OBSERVATIONS
COUPLED WITH VISIBLE SATELLITE POSITION ESTIMATES SUGGEST THAT THE
CENTER OF KATRINA IS OVER THE SOUTH CENTRAL PORTION OF THE YUCATAN
PENINSULA.  THIS REPRESENTS A SLIGHT WESTWARD ADJUSTMENT FROM THE
PREVIOUS ADVISORY.  WEAK SYSTEMS LIKE THIS CAN BE A CHALLENGE TO
TRACK...ESPECIALLY OVER LAND.  THE INITIAL MOTION ESTIMATE IS NOW
325/08 KT.
 
ANALYSIS OF UPPER-AIR DATA OVER THE WESTERN CARIBBEAN AND THE GULF
OF MEXICO SHOWS A MID-LEVEL HIGH NEAR EASTERN/CENTRAL CUBA WITH A
RIDGE AXIS EXTENDING ALONG 22N/23N.  KATRINA HAS CONTINUED TO MOVE
NORTHWEST UNDER THE INFLUENCE OF THIS FEATURE AND SHOULD BEGIN TO
TURN NORTH...THEN NORTH-NORTHEAST MONDAY AS IT PASSES NORTH OF THE 
AXIS. THE SYSTEM SHOULD BEGIN TO ACCELERATE TO THE NORTHEAST LATE
MONDAY/TUESDAY IN RESPONSE TO THE DEEP-LAYER TROUGH CURRENTLY OVER
EASTERN TEXAS SHIFTING EASTWARD INTO THE SOUTHEAST UNITED STATES.
THE OFFICIAL FORECAST FOLLOWS THIS SCENARIO AND IS SLIGHTLY SLOWER
AND TO THE RIGHT OF THE PREVIOUS ADVISORY.  WITH THE AVIATION MODEL
RUNNING LATE TODAY...THERE WAS LITTLE TRACK GUIDANCE AVAILABLE FROM
12Z MODELS RUNS. 

THE INITIAL INTENSITY REMAINS 25 KT.  THE FORECAST BRINGS KATRINA
TO MINIMAL TROPICAL STORM STRENGTH BY 24 HOURS AND MAINTAINS THAT
INTENSITY THROUGH THE REMAINDER OF THE PERIOD. AFTER 36 HOURS...THE
QUESTION IS WHETHER KATRINA MAINTAINS ITS IDENTITY OR IS ABSORBED BY
THE SYSTEM MENTIONED ABOVE. KATRINA IS FORECAST BECOME EXTRATROPICAL
BY 72 HOURS AS IT MERGES WITH...OR IS ABSORBED BY...THE FRONTAL
SYSTEM APPROACHING FROM THE WEST.
 
BASED ON THE PROJECT TRACK SCENARIO A TROPICAL STORM WATCH MAY BE
REQUIRED FOR PORTIONS OF THE WEST FLORIDA COAST TONIGHT OR EARLY
FRIDAY.  ALL INTERESTS ELSEWHERE IN FLORIDA...AND IN THE CENTRAL 
AND EASTERN GULF OF MEXICO SHOULD CLOSELY MONITOR THE PROGRESS OF
THIS SYSTEM.
 
GUINEY
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     31/2100Z 19.5N  89.4W    25 KTS
12HR VT     01/0600Z 20.6N  89.9W    25 KTS
24HR VT     01/1800Z 22.4N  89.9W    35 KTS
36HR VT     02/0600Z 25.0N  87.8W    35 KTS
48HR VT     02/1800Z 27.5N  84.0W    35 KTS
72HR VT     03/1800Z 34.0N  71.0W    35 KTS...EXTRATROPICAL
 
 
NNNN