000
AXNT20 KNHC 261115
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI DEC 26 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1045 UTC.

...THE ITCZ...
ITCZ IS ANALYZED ALONG 8N10W 5N22W 4N45W 3N51W. CLUSTERS OF 
SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150/180 NM S OF 
THE ITCZ FROM 16W-21W AND AND FROM 32W-37W. 

...DISCUSSION...

GULF OF MEXICO...
THE GULF IS DOMINATED BY AN UPPER RIDGE THAT EXTENDS FROM THE 
CARIBBEAN ACROSS CUBA AND THE FLORIDA PENINSULA WITH 
MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR NOTED ACROSS THE 
ENTIRE BASIN. SURFACE RIDGE ANCHORED IN THE W ATLC COVERS THE 
GULF GIVING THE ENTIRE GULF RETURN FLOW WITH SCATTERED PATCHES 
OF LOW CLOUDS AND ISOLATED SHOWERS. PATCHES OF FOG ARE INLAND 
AND WITHIN 60 NM ALONG THE ENTIRE N GULF COAST FROM TAMPA 
FLORIDA TO BROWNSVILLE TEXAS. NEXT MAJOR FRONT TO ENTER THE GULF 
IS EXPECTED LATE SAT/EARLY SUN.

CARIBBEAN SEA...
BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED OVER SOUTH 
AMERICA AND A RIDGE AXIS EXTENDING NNW ACROSS CUBA AND THE 
FLORIDA PENINSULA INCLUDING THE W ATLC COVERING MUCH OF THE 
CARIBBEAN WITH STRONG SUBSIDENCE AND DRY AIR. SURFACE RIDGE 
REMAINS OVER THE ATLC AND WITH THE LOWER PRESSURE OVER SOUTH 
AMERICA IS PRODUCING MODERATE/STRONG ELY TRADE WINDS. THESE 
TRADE WINDS COUPLED WITH LOW LEVEL CONVERGENCE IS GENERATING 
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE 
SW CARIBBEAN S OF 16N W OF 81W TO INLAND OVER CENTRAL AMERICA. 
THE HIGH PRESSURE OVER THE ATLC IS EXPECTED TO CONTINUE TO SHIFT 
E AND WEAKEN. HOWEVER...THE MODERATE/STRONG TRADE WINDS WILL 
CONTINUE THROUGH THE WEEKEND DIMINISHING ON MON. 
 
ATLANTIC OCEAN...
HIGH PRESSURE DOMINATES THE W AND CENTRAL ATLC EXTENDING W TO 
OVER THE GULF OF MEXICO ANCHORED BY A 1028 MB HIGH NEAR 31N71W 
WITH A 1027 MB HIGH IN THE N/CENTRAL ATLC NEAR 32N48W. THE UPPER 
RIDGE THAT DOMINATES THE CARIBBEAN EXTENDS OVER THE W ATLC TO 
50W WITH THE AXIS EXTENDING ACROSS CUBA TO OVER THE FLORIDA 
PENINSULA. A COLD FRONT DRAPES ACROSS THE E ATLC INTO THE 
CENTRAL ATLC THROUGH 32N20W EXTENDING SW ALONG 24N26W TO 20N38W 
THEN DISSIPATING W TO 21N52W. BROKEN/OVERCAST LOW CLOUDS WITH 
ISOLATED SHOWERS ARE WITHIN 60 NM NW OF THE FRONT AND BROKEN 
STRATOCUMULUS CLOUDS COVERING THE REMAINDER OF THE AREA N OF THE 
FRONT AND THE CENTRAL ATLC E OF 65W. THE ASSOCIATED UPPER TROUGH 
EXTENDS THROUGH 32N28W S TO 26N26W THEN SW INTO THE TROPICS 
ALONG 22N41W TO JUST E OF THE LESSER ANTILLES NEAR 13N59W. UPPER 
DIFFLUENCE IS SE OF THIS UPPER TROUGH COUPLED WITH AN UPPER 
RIDGE AMPLIFIED ALONG THE COAST OF W AFRICA IS ENHANCING 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM OF 
LINE FROM SOUTH AMERICA NEAR 6N56W TO 13N36W. MODERATE/STRONG 
ELY TRADE WINDS REMAIN ACROSS THE TROPICAL ATLC AND WILL 
CONTINUE THROUGH THE WEEKEND. 

$$
WALLACE