000
AXNT20 KNHC 310548
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST THR DEC 31 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 
0545 UTC.

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM WEST AFRICA...OVER THE SOUTH 
COAST OF SIERRA LEONE NEAR 7N12W...THROUGH 5.5N20W 3N30W 
2N40W...TO NORTHEAST BRAZIL NEAR THE CITY OF MAPACA AT EQ50W. 
SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE COAST OF 
BRAZIL FROM 2S TO 1N BETWEEN 44W AND 50W. ANOTHER AREA OF 
SCATTERED SHOWERS IS WITHIN 100 NM OF THE ITCZ BETWEEN 20W AND 
32W. 

...DISCUSSION...

THE GULF OF MEXICO...

A 1015 MB LOW IS CENTERED INLAND OVER LOUISIANA NEAR 31N92W. A 
COLD FRONT EXTENDS SOUTH FROM THE LOW TO NEAR TAMPICO MEXICO AT 
20N97W. THIS FRONT IS MOVING EASTWARD INTO THE CENTRAL BASIN. 
SHIP AND BUOY OBSERVATION SHOW NORTHWEST WINDS 10 TO 15 KTS 
BEHIND THE FRONT. TO THE EAST OF THE FRONT AND REMAINDER OF THE 
GULF...OBSERVATIONS SHOW SOUTHEAST WINDS 10 TO 20 KTS. IN 
THE UPPER LEVELS...A WIDE TROUGH COVERING MUCH OF THE 
CONTINENTAL US IS PRODUCING SOUTHWEST UPPER LEVEL FLOW OVER THE 
GULF. RADAR IMAGERY SHOWS A BROAD LINE OF WEAK TO MODERATE 
SHOWERS MOVING ALONG THE NORTH GULF COAST. THIS SHOWERS ARE 
MOVING PARALLEL TO THE 30N LINE ENTERING THE FLORIDA PANHANDLE. 
LOOK FOR THE SURFACE LOW TO MOVE TO SOUTH GEORGIA IN 24 HOURS. 
PRECIPITATION WILL MOVE ACROSS NORTHERN FLORIDA INTO THE WESTERN 
ATLANTIC OCEAN OVER THE NEXT 24 TO 36 HOURS.  

THE CARIBBEAN SEA...

UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE MOST OF THE 
CARIBBEAN SEA...BRINGING STRONG SUBSIDENCE OF AIR ALOFT AND 
SUPPRESSING DEEP CONVECTION ACROSS THE BASIN. SHIP AND BUOY 
OBSERVATIONS SHOW SURFACE EASTERLY WINDS 10 TO 20 KTS ACROSS THE 
BASIN. THE SOUTH END TIP OF A COLD FRONT IS PASSING NORTH OF THE 
ISLAND OF PUERTO RICO. DOPPLER RADAR IMAGERY SHOWS AN AREA OF 
SHOWERS MOVING TO THE SOUTHWEST 30 NM SOUTH OF PUERTO RICO. 
SATELLITE IMAGERY INDICATES THESE SHOWERS MAY EXTEND 
SOUTHWESTWARD TO 15N70W. THE ACTIVITY WILL LESSEN AS THE FRONT 
MOVES OUT OF THE AREA. ELSEWHERE...EXPECT LITTLE CHANGE OVER 
THE NEXT 24 HOURS.  

THE ATLANTIC OCEAN...

AN UPPER LEVEL RIDGE ENTERS THE WESTERN ATLANTIC...MOVING ALONG 
A SURFACE HIGH PRESSURE OF 1031 MB INTO THE WESTERN BASIN. THUS 
LIGHT SURFACE NORTHEAST WINDS ARE OBSERVED IN THIS REGION. AN 
UPPER LEVEL TROUGH IS MOVING ACROSS THE CENTRAL ATLANTIC. THE 
TAIL END OF A COLD FRONT ENTERS THE CENTRAL ATLANTIC NEAR 32N42W 
AND EXTENDS SOUTHWEST ALONG 23N50W AND 19N60W. BROKEN COLD AIR 
STRATOCUMULUS CLOUDS ARE WEST OF THE FRONT TO 80W. WEAK 
CONVECTION IS FOUND WITHIN 120 NM EAST OF THE FRONT. GALE FORCE 
WINDS ARE EXPECTED TO DEVELOP OVER THE NEXT 24 TO 36 HOURS 
WITHIN 300 NM WEST OF THE FRONT NORTH OF 29N. AN UPPER LEVEL 
RIDGE OVER THE EASTERN ATLANTIC IS FEEDING A 1024 MB HIGH NEAR 
28N28W. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONT TO MOVE EAST 
INTO THE EASTERN ATLANTIC NEAR 35W WITH CONVECTION.  

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

$$

GARCIA