000
AXNT20 KNHC 120552
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SAT DEC 12 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.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N12W 2N30W EQ50W. WIDELY SCATTERED 
MODERATE CONVECTION IS FROM 2N-5N BETWEEN 11W-18W. SCATTERED 
MODERATE CONVECTION IS FROM 2N-4N BETWEEN 29W-32W...AND FROM EQ-2N 
BETWEEN 34W-36W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...A 1014 MB LOW IS OVER THE NW GULF OF MEXICO NEAR 
27N96W. A COLD FRONT EXTENDS SW FROM THE LOW TO NEAR TAMPICO MEXICO 
ALONG 24N96W 23N98W. A WARM FRONT EXTENDS E FROM THE LOW TO THE 
CENTRAL GULF ALONG 28N92W 26N87W. A STATIONARY FRONT CONTINUES TO 
THE STRAITS OF FLORIDA AT 24N80W. SCATTERED SHOWERS COVER A MAJORITY 
OF THE GULF NORTH OF THESE FRONTS. MOSAIC DOPPLER RADAR IMAGERY 
INDICATES THESE SHOWERS OVER THE EXTREME SOUTHERN FLORIDA PENINSULA 
AND FLORIDA KEYS...AS WELL AS ALONG THE TEXAS AND SE CONUS GULF 
COAST. WINDS N OF THE WARM AND STATIONARY FRONTS ARE FROM THE ENE AT 
20-25 KT. IN THE UPPER LEVELS...AN UPPER LEVEL HIGH IS CENTERED OVER 
THE CAYMAN ISLANDS PRODUCING SW UPPER LEVEL WINDS OVER THE ENTIRE 
GULF OF MEXICO. CONSIDERABLE UPPER LEVEL MOISTURE IS OVER THE N GULF 
N OF 28N. THE REMAINDER OF THE GULF HAS STRONG SUBSIDENCE. EXPECT... 
THE SURFACE LOW TO MOVE NE TO S MISSISSIPPI NEAR 32N91W IN 24 HOURS. 
THE COLD FRONT WILL EXTEND SW FROM THE LOW TO NEAR TAMPICO MEXICO 
WITH SHOWERS. THE WARM FRONT WILL THEN BE INLAND OVER THE N GULF 
STATES. 10-15 SE SURFACE FLOW WILL BE OVER THE GULF E OF THE COLD 
FRONT.    

CARIBBEAN SEA... 
A 1007 MB LOW IS CENTERED OVER N COLOMBIA NEAR 9N74W. A RELATIVELY 
TIGHT SURFACE GRADIENT OVER THE CARIBBEAN IS PRODUCING STRONG 
TRADEWINDS. PATCHES OF BROKEN LOW CLOUDS WITH ISOLATED SHOWERS DOTS 
THE CARIBBEAN MOSTLY N OF 14N. IN THE UPPER LEVELS...AN UPPER LEVEL 
HIGH IS CENTERED OVER THE CAYMAN ISLANDS NEAR 19N81W. A SMALL UPPER 
LEVEL LOW IS OVER THE SOUTH CENTRAL CARIBBEAN NEAR 13N70W. STRONG 
SUBSIDENCE COVERS THE ENTIRE CARIBBEAN SUPPRESSING CONVECTION. 
EXPECT...SHOWERS OVER THE YUCATAN PENINSULA OVER THE NEXT 24 
HOURS...AND LITTLE CHANGE ELSEWHERE.    

ATLANTIC OCEAN...
A COLD FRONT IS OVER THE W ATLANTIC ENTERING THE DISCUSSION AREA 
NEAR 32N57W CONTINUING SW TO 27N70W. A STATIONARY FRONT CONTINUES TO 
THE STRAITS OF FLORIDA NEAR 24N80W. ISOLATED SHOWERS ARE WITHIN 90 
NM OF THE FRONTS. A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 
28N43W PRODUCING FAIR WEATHER. A COLD FRONT IS OVER THE E ATLANTIC 
FROM 32N13W THROUGH THE CANARY ISLANDS TO 25N20W. SCATTERED SHOWERS 
ARE WITHIN 90 NM OF THE FRONT. IN THE UPPER LEVELS...AN UPPER LEVEL 
RIDGE IS N OF 20N W OF 40W. AN UPPER LEVEL TROUGH IS OVER THE E 
ATLANTIC N OF 15N E OF 40W. AN EMBEDDED UPPER LEVEL LOW IS N OF THE 
CANARY ISLANDS NEAR 35N15W. ZONAL FLOW IS OVER THE REMAINDER OF THE 
AREA. EXPECT...THE COLD FRONT TO MOVE E OVER THE NEXT 24 HOURS AND 
EXTEND FROM 32N38W TO 25N60W TO THE N BAHAMAS WITH CONVECTION 
HEAVIEST N OF 24N W OF 70W.    

$$
FORMOSA