000
AXNT20 KNHC 250550
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST FRI DEC 25 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 0515 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N8W 2N30W 1N40W EQ50W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 1N-4N 
BETWEEN 26W-30W. ISOLATED MODERATE CONVECTION IS FROM 2N-4N 
BETWEEN 11W-20W. 

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 0300 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE 
TO THE BAY OF CAMPECHE ALONG 31N86W 24N90W 19N96W. SCATTERED 
SHOWERS ARE WITHIN 30 NM OF THE FRONT. WIDELY SCATTERED MODERATE 
CONVECTION IS E OF THE FRONT OVER THE NE GULF OF MEXICO FROM 
27N-30N BETWEEN 84W-86W. 20-30 KT NW WINDS ARE OVER THE W GULF 
BEHIND THE FRONT. A SECONDARY COLD FRONT EXTENDS FROM LOUISIANA 
TO THE NW GULF OF MEXICO ALONG 31N91W 26N93W BRINGING IN COLDER 
TEMPERATURES...MORE LOW CLOUDS...AND HIGHER WINDS OVER THE NW 
GULF. ELSEWHERE E OF THE FRONTS...RETURN FLOW WITH A TIGHT 
SURFACE GRADIENT IS PRODUCING 20-25 KT SE SURFACE WINDS AND  
BROKEN TO OVERCAST MULTILAYERED CLOUDS OVER THE E GULF OF MEXICO 
AND FLORIDA. IN THE UPPER LEVELS...90-110 KT ZONAL FLOW WITH 
STRONG SUBSIDENCE IS OVER THE W GULF W OF 90W. 50-70 KT ZONAL 
FLOW WITH CONSIDERABLE UPPER LEVEL MOISTURE COVERS THE E GULF E 
OF 90W. EXPECT IN 24 HOURS...FOR THE TAIL END OF A COLD FRONT TO 
EXTEND FROM S FLORIDA TO W CUBA WITH 10-15 KT NW WINDS OVER MOST 
OF GULF W OF THE FRONT. CONVECTION WILL PERSIST OVER S FLORIDA 
AND THE STRAITS OF FLORIDA.  

THE CARIBBEAN SEA...
THE SURFACE PRESSURE GRADIENT HAS SLACKENED OVER THE CARIBBEAN 
SEA AND CENTRAL AMERICA THUS MODERATE TRADEWINDS ARE NOTED OVER 
THE AREA. SCATTERED MODERATE CONVECTION IS OVER PUERTO RICO AND 
THE LEEWARD ISLANDS FROM 18N-20N BETWEEN 63W-67W. THE REMAINDER 
OF THE SEA AND CENTRAL AMERICA HAS MOSTLY FAIR SKIES. IN THE 
UPPER LEVELS...A TROUGH IS OVER THE WESTERN CARIBBEAN W OF 70W 
WITH AXIS ALONG 80W. AN UPPER LEVEL RIDGE IS OVER THE REMAINDER 
OF THE CARIBBEAN PRODUCING SW UPPER LEVEL WINDS. UPPER LEVEL 
MOISTURE IS OVER THE EASTERN CARIBBEAN E OF 68W WHILE STRONG 
SUBSIDENCE IS OVER THE REMAINDER OF THE CARIBBEAN. EXPECT OVER 
THE NEXT 24 HOURS FOR CONTINUED SHOWERS AND CONVECTION OVER THE 
LEEWARD ISLANDS.

THE ATLANTIC OCEAN...
THE TAIL END OF A COLD FRONT IS OVER THE W ATLANTIC ALONG 32N58W 
29N66W. A 1011 MB LOW IS CENTERED OVER THE S BAHAMAS NEAR 
22N70W. A STATIONARY FRONT EXTENDS E FROM THE LOW TO 22N64W. 
SCATTERED MODERATE CONVECTION IS N OF THE LEEWARD ISLANDS FROM 
20N-22N BETWEEN 60W-65W. A 1018 MB HIGH IS OVER THE CENTRAL 
ATLANTIC NEAR 25N51W. IN THE UPPER LEVELS...A RIDGE IS OVER THE 
W ATLANTIC W OF 70W. AN UPPER LEVEL TROUGH IS FURTHER E OVER THE 
W ATLANTIC N OF 20N BETWEEN 50W-70W. ANOTHER UPPER LEVEL RIDGE 
IS OVER THE CENTRAL ATLANTIC N OF 20N BETWEEN 30W-50W. ZONAL 
FLOW IS OVER THE E ATLANTIC N OF 20N E OF 30W TO THE AFRICAN 
COAST. IN THE TROPICS AN UPPER LEVEL HIGH IS CENTERED E OF THE 
LESSER ANTILLES NEAR 12N55W. A RIDGE AXIS EXTENDS E TO THE CAPE 
VERDE ISLANDS NEAR 16N25W. AN UPPER LEVEL LOW IS CENTERED 
FURTHER S NEAR 4N40W. EXPECT IN 24 HOURS FOR A COLD FRONT TO BE 
OVER THE W ATLANTIC E OF FLORIDA WITH CONVECTION...AND ANOTHER 
COLD FRONT TO BE OVER THE CENTRAL ATLANTIC FROM 32N40W TO N OF 
THE LEEWARD ISLANDS NEAR 20N60W WITH CONVECTION. ALSO EXPECT 
GALE FORCE WINDS BEHIND THIS FRONT OVER THE CENTRAL ATLANTIC 
NEAR 30N50W.  

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE.

$$
FORMOSA