000
AXNT20 KNHC 102321
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT JAN 10 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 8N13W 3N25W CROSSING THE EQUATOR NEAR 39W 
AND INTO NE BRAZIL NEAR 1S47W. SMALL CLUSTERS OF MODERATE 
CONVECTION ARE WITHIN 40 NM NORTH OF THE AXIS BETWEEN 21W-22W 
AND FROM 2N-4N BETWEEN 31W-33W.  

...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT HAS MOVED INTO THE NW GULF THIS AFTERNOON. AS OF 
2100 UTC...THE BOUNDARY STRETCHED FROM LOUISIANA NEAR 30N93W 
ALONG 28N94W TO THE TEXAS/MEXICO BORDER. SCATTERED SHOWERS AND 
THUNDERSTORMS ARE EVIDENT ON DOPPLER RADAR WITHIN 40 NM OF THE 
FRONT. A 15 DEGREE TEMPERATURE GRADIENT IS EVIDENT ACROSS THE 
FRONTAL BOUNDARY. SW RETURN FLOW 15-20 KT AROUND THE WESTERN 
PERIPHERY OF A SFC HIGH PRESSURE RIDGE COVERS THE GULF E OF THE 
FRONT. BEHIND THE FRONT...WINDS SHIFT N AND INCREASE TO 20-30 
KT...WITH GALE FORCE CONDITIONS EXPECTED IN THE SW GULF SUN 
THROUGH MON. EXPECT THE COLD FRONT TO MOVE QUICKLY EASTWARD 
NEARING THE YUCATAN CHANNEL LATE SUN OR EARLY MON.

CARIBBEAN SEA...
A SFC HIGH PRESSURE RIDGE OVER THE W ATLC IS MAINTAINING FRESH 
TO STRONG TRADE WINDS ACROSS THE CARIBBEAN WITH THE STRONGEST 
WINDS ALONG THE COAST OF COLOMBIA. STRONG SUBSIDENCE ALOFT IS 
PREVENTING THE FORMATION OF DEEP CONVECTION. ONLY PATCHY 
LOW-LEVEL CLOUDS WITH SCATTERED SHOWERS DOT THE REGION. EXPECT 
LITTLE CHANGE DURING THE NEXT FEW DAYS UNTIL A STRONG COLD FRONT 
IN THE GULF OF MEXICO ENTERS THE NW CARIBBEAN ON TUE.

ATLANTIC OCEAN...
TRANQUIL CONDITIONS PERSIST IN THE W ATLC UNDER THE INFLUENCE OF 
A SFC RIDGE CENTERED ON A 1028 MB HIGH NEAR 33N70W. A SFC TROUGH 
DEPICTS A LINE OF SCATTERED CLOUDS...REMNANTS OF A WEAK COLD 
FRONT THAT TRAVERSED THE AREA OVER THE LAST FEW DAYS. A STRONGER 
COLD FRONT ENTERS THE DISCUSSION AREA NEAR 31N48W AND EXTENDS TO 
27N54W WHERE IT CONTINUES AS A STATIONARY FRONT TO THE BAHAMAS 
NEAR 23N73W. SCATTERED SHOWERS WITH POSSIBLE ISOLATED 
THUNDERSTORMS ARE WITHIN 90 NM OF THE FRONT N OF 24N. THE 
REMAINDER OF THE ATLC IS DOMINATED BY A STRONG HIGH PRESSURE 
RIDGE ANCHORED ON A 1028 MB SFC HIGH NEAR 28N38W. ALOFT...UPPER 
LEVEL DIFFLUENCE IS GENERATING A LARGE AREA OF MODERATE 
CONVECTION FROM 13N-23N BETWEEN 24W-37W. EXPECT THE W ATLC RIDGE 
TO SHIFT TO THE CENTRAL ATLC AS A COLD FRONT EMERGES FROM THE NE 
FLORIDA COAST LATE SUN.    

$$
WADDINGTON