000
AXNT20 KNHC 030541
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SAT JAN 03 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0445 UTC.

...THE ITCZ...

ITCZ IS ANALYZED ALONG 11N13W 5N25W 2N40W CROSSING THE EQUATOR 
NEAR 48W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE 
FROM 6N TO THE EQUATOR BETWEEN 2W-20W. CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 60 NM OF A LINE 
FROM 6N41W TO 9N51W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL WLY ZONAL FLOW IS ACROSS THE GULF ADVECTING UPPER 
LEVEL MOISTURE FROM THE E PACIFIC ACROSS MEXICO AND THE GULF N 
OF 23N. A JET STREAM WITH WINDS OF 80 TO 95 KT IS ALSO ACROSS 
THE N GULF AND FLORIDA BETWEEN 23N AND 29N. A SURFACE RIDGE 
REMAINS OVER THE GULF ANCHORED BY A 1020 MB HIGH CENTERED IN THE 
W ATLC GIVING THE ENTIRE GULF SLY SURFACE RETURN FLOW. THIS IS 
GENERATING ISOLATED SHOWERS MAINLY S OF 25N E OF 91W. PATCHES OF 
FOG ARE BEING REPORTED ACROSS THE N GULF COAST STATES FROM 
TALLAHASSEE FLORIDA TO GALVESTON TEXAS. THE NEXT COLD FRONT IS 
EXPECTED TO ENTER THE GULF LATE SUN.

CARIBBEAN SEA...
A BROAD UPPER RIDGE ANCHORED OVER SOUTH AMERICA IS GIVING THE 
CARIBBEAN SW TO W UPPER FLOW. STRONG SUBSIDENCE AND DRY STABLE 
AIR CONTINUE TO DOMINATE THE CARIBBEAN W OF 70. A SURFACE TROUGH 
IS IN THE SE CARIBBEAN ALONG 65W S OF 15N WITH WEAK CYCLONIC 
WIND FLOW EVIDENT ON SATELLITE IMAGERY. LOW-MID LEVEL CLOUDINESS 
WITH EMBEDDED SCATTERED SHOWERS ARE ACROSS THE SE CARIBBEAN S OF 
16N E OF 67W TO ACROSS THE WINDWARD ISLANDS. ELSEWHERE... 
MODERATE TRADE WINDS ARE PRODUCING AN AREA OF SCATTERED SHOWERS 
FROM 15N-19N BETWEEN 78W-83W AND CONTINUE TO USHER IN ISOLATED 
FAST MOVING SHOWERS OVER THE REMAINDER OF THE CARIBBEAN. 

ATLANTIC...
A WEAK UPPER TROUGH DIPS S OVER THE W ATLC N OF 28N FROM 65W TO 
THE NE FLORIDA. A SURFACE RIDGE COVERS THE W ATLC ANCHORED BY A 
1020 MB HIGH CENTERED S OF BERMUDA NEAR 30N65W. A DEEP LAYERED 
UPPER LEVEL TROUGH IS ACROSS THE N/CENTRAL ATLC N OF THE REGION 
SUPPORTING A COLD FRONT ENTERING THE REGION NEAR 32N42W TO 
25N70W WHERE IT BECOMES STATIONARY TO JUST E OF THE BAHAMAS NEAR 
24N76W. A WEAKENING PRE-FRONTAL TROUGH EXTENDS FROM 27N49W TO 
23N59W. ISOLATED SHOWERS ARE N OF 28N WITHIN 120 NM E OF THE 
FRONT WITH PATCHES OF BROKEN/OVERCAST LOW CLOUDS AND ISOLATED 
SHOWERS WITHIN 90 NM ON EITHER SIDE OF THE FRONTAL BOUNDARY W OF 
46W. A JETSTREAM WITH WINDS OF 80 TO 110 KT IS ACROSS THE W ATLC 
WITHIN 200 NM OF LINE FROM ACROSS THE GULF OF MEXICO AND FLORIDA 
NEAR 26N80W 26N69W TO BEYOND 32N32N59W. UPPER WESTERLY ZONAL 
FLOW DOMINATES THE REMAINDER OF THE ATLC. E OF THE FRONT OVER 
THE E ATLC...A SURFACE RIDGE IS ANCHORED BY A 1026 MB HIGH 
NEAR 34N26W.

$$
WALLACE