000
AXNT20 KNHC 241733
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SAT JAN 24 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1645 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N2W 2N10W 1N33W CROSSING THE 
EQUATOR NEAR 39W AND INTO BRAZIL NEAR 2S45W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE S OF 6N W OF 
43W TO INLAND OVER SOUTH AMERICA.
 
...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER TROUGH IS MOVING E ACROSS THE E US AND THE GULF OF 
MEXICO WITH A SHORTWAVE ALONG THE LOWER MISSISSIPPI VALLEY. AT 
24/1500 UTC...THE ASSOCIATED COLD FRONT EXTENDS FROM A WEAK 1021 
MB LOW NEAR JASPER TEXAS CONTINUING S JUST OFF THE TEXAS COAST 
TO NEAR CORPUS CHRISTI THEN W ACROSS S TEXAS AND NE MEXICO WITH 
A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM 28N94W ACROSS S 
TEXAS TO 26N99W. SCATTERED SHOWERS WITH POSSIBLE EMBEDDED 
ISOLATED THUNDERSTORMS ARE N OF 28N E OF 93W AND N OF A LINE 
FROM 28N93W TO BROWNSVILLE TEXAS. A SURFACE RIDGE DOMINATES THE 
REMAINDER OF THE GULF EXTENDING FROM THE W ATLC THROUGH A 1024 
MB HIGH OVER LAKE OKEECHOBEE FLORIDA. MODERATE/STRONG 
SUBSIDENCE/DRY AIR CONTINUE TO DOMINATE THE BAY OF CAMPECHE AND 
SE GULF WITH WITH MORE MOVING OFF TEXAS OVER THE NW GULF GIVING 
THE REMAINDER OF THE GULF PATCHES OF LOW LEVEL CLOUDS BUT NO 
SIGNIFICANT SHOWER ACTIVITY. THE FRONT IS FORECAST MOVE E TODAY 
TO THE BIG BEND AREA OF FLORIDA EXTENDING TO NE MEXICO AND STALL 
TONIGHT THEN WEAKEN AND DISSIPATE EARLY MON. 

CARIBBEAN SEA...
UPPER LEVEL TROUGH FROM THE W/CENTRAL ATLC DIPS ACROSS THE N 
CARIBBEAN BETWEEN PUERTO RICO AND HISPANIOLA AND EXTENDING A 
SURFACE TROUGH ACROSS THE E DOMINICAN REPUBLIC TO 15N72W. THIS 
SURFACE TROUGH CONTINUES TO GENERATE ABUNDANT LOW LEVEL CLOUDS 
WITH SCATTERED SHOWERS OVER HISPANIOLA AND THE ADJACENT COASTAL 
CARIBBEAN WATERS N OF 15N BETWEEN 69W-73W. AN UPPER LOW IS IN 
THE W TROPICAL ATLC COVERING THE LESSER ANTILLES WHILE THE 
REMAINDER OF THE UPPER LEVELS OF THE CARIBBEAN ARE DOMINATED BY 
A BROAD UPPER RIDGE ANCHORED OVER VENEZUELA. STRONG SUBSIDENCE 
AND DRY AIR CONTINUE TO DOMINATE THE ENTIRE AREA. HIGH PRESSURE 
N OF THE AREA IS MAINTAINING MODERATE/STRONG EASTERLY TRADE 
WINDS ACROSS MUCH OF THE CARIBBEAN BANKING LOW LEVEL CLOUDS WITH 
SCATTERED SHOWERS ALONG THE MOUNTAINS OF CENTRAL AMERICA AND THE 
SW CARIBBEAN WATERS FROM CENTRAL PANAMA TO CENTRAL NICARAGUA AND 
IN THE GULF OF HONDURAS FROM CENTRAL HONDURAS TO ALL OF BELIZE. 

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS OVER THE W/CENTRAL ATLC SUPPORTING A 
LINGERING STATIONARY FRONT ENTERING THE AREA NEAR 32N54W SSW 
ALONG 26N61W TO THE E DOMINICAN REPUBLIC NEAR 19N69W WHERE IT 
CONTINUES INTO THE CARIBBEAN AS A SURFACE TROUGH. ISOLATED 
SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE FRONT N OF 27N. A 
BROAD UPPER LOW IS IN THE W TROPICAL ATLC CENTERED NEAR 16N52W 
COVERING THE AREA FROM 7N-22N BETWEEN 46W-63W INCLUDING THE 
LESSER ANTILLES. A SECOND UPPER LOW IS CENTERED JUST NE OF THE 
CAPE VERDE ISLANDS EXTENDING AN UPPER TROUGH SW TO 11N36W. THE 
REMAINDER OF THE ATLC IS DOMINATE BY UPPER LEVEL RIDGES. ONE 
SURFACE RIDGE EXTENDS FROM A 1022 MB HIGH ENE OF BERMUDA NEAR 
34N57W THROUGH A 1023 MB HIGH NEAR 28N70W AND A 1024 MB HIGH 
OVER THE FLORIDA PENINSULA CONTINUING OVER THE GULF OF MEXICO. A 
SECOND LARGER SURFACE RIDGE COVERS THE AREA E OF THE FRONT TO 
INLAND OVER AFRICA ANCHORED BY A 1030 MB HIGH NEAR 30N30W. 

$$
WALLACE