000
AXNT20 KNHC 250600
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SAT DEC 25 2010

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...

ITCZ AXIS IS ANALYZED FROM THE COAST OF LIBERIA NEAR 6N11W 
WESTWARD ALONG 4N20W 3N30W 3N40W TO THE COAST OF BRAZIL NEAR 
1N50W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM ON EITHER 
SIDE OF THE AXIS BETWEEN 15W AND 45W. 

...DISCUSSION...

GULF OF MEXICO...
A STRONG UPPER LEVEL SHORTWAVE QUICKLY MOVES ACROSS SE TEXAS 
SUPPORTING A 1014 MB LOW EMERGING OFF THE TEXAN COAST NEAR 
30N95W. A COLD FRONT EXTENDS SW FROM THE LOW CENTER ALONG THE 
TEXAS COAST TO BROWNSVILLE. A PRE-FRONTAL SURFACE TROUGH IS 
STARTING TO DEVELOP SOUTH OF THE LOW CENTER NEAR 28N95W AND 
ALIGNS WITHIN 60 NM ACROSS THE WESTERN GULF COAST TO VERACRUZ 
MEXICO. MOSAIC DOPPLER RADAR IMAGERY INDICATED HEAVY SHOWERS AND 
THUNDERSTORMS N OF 25N W OF 93W. THIS SYSTEM WILL CONTINUE TO 
TRACK EASTWARD ACROSS THE NORTHERN GULF WITH MODERATE TO STRONG 
CONVECTION OVER THE NEXT 24 HOURS. FAIR WEATHER CONDITIONS ARE 
ELSEWHERE AT THE MOMENT. 

CARIBBEAN SEA...
DRY AIR AND SUBSIDENCE ALOFT IS NOTED ON WATER VAPOR IMAGERY 
OVER THE NW AND N-CENTRAL CARIBBEAN WITH MOSTLY ZONAL FLOW ALOFT 
ACROSS THIS AREAS. HOWEVER...THE FLOW TURNS MORE SOUTHWESTERLY 
ELSEWHERE ACROSS THE REGION. THIS IS BRINGING DEEP MOISTURE FROM 
NORTHERN SOUTH AMERICA TO MUCH OF THE SOUTHERN HALF OF THE 
CARIBBEAN...AS WELL AS ENHANCING CONVECTION FOCUSED ALONG A 
SHEAR AXIS EXTENDING ACROSS THE SOUTHERN CARIBBEAN ALONG 14N61W 
13N70W 10N80W. NNE FLOW N OF THE BOUNDARY AND TRADE WINDS S OF 
THE BOUNDARY ARE CONVERGING ALONG THE AXIS TO GENERATE SCATTERED 
SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 60 NM EITHER SIDE OF 
THE LINE. COMPUTER MODELS SUGGEST THE CONVECTION WILL LINGER 
OVER THE AREA FOR THE NEXT FEW DAYS.

ATLANTIC OCEAN...
AN UPPER RIDGE THAT COVERS THE FAR W ATLC W OF 65W PROVIDING 
RELATIVELY FAIR WEATHER CONDITIONS ACROSS THE AREA. HOWEVER...A  
LARGE AND BROAD DEEP LAYER TROUGH IS OVER THE NORTH CENTRAL ATLC 
BY A 966 MB LOW CENTERED E OF NEWFOUNDLAND NEAR 47N47W THAT 
CONTINUES TO EXTEND INFLUENCE OVER MUCH OF THE CENTRAL ATLC. 
THIS SYSTEM SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION 
AREA NEAR 32N40W AND EXTENDS SW ALONG 25N50W 21N60W TO NORTHERN 
HISPANIOLA NEAR 20N71W. ISOLATED SHOWERS ARE WITHIN 30 NM E OF 
THE FRONT WITH DENSE LOW LEVEL CLOUDS AND POSSIBLE ISOLATED 
SHOWERS WITHIN 60 NM W OF THE FRONT WITH WINDS UP TO 30 KT. COLD 
AIR STRATOCUMULUS CLOUDS COVER THE REMAINDER OF THE ATLC W OF 
THE FRONT. TO THE SW OF THIS FRONT INTO THE WEST TROPICAL 
ATLC...A NEARLY STATIONARY SURFACE TROUGH IS ANALYZED EAST OF 
THE LESSER ANTILLES FROM 18N54W TO 10N55W SUPPORTING ISOLATED 
SHOWERS AND THUNDERSTORMS FROM 18N TO 22N BETWEEN 47W AND 52W. A 
SHEAR AXIS IS WEST OF THE SURFACE TROUGH FROM 15N57W WSW INTO 
THE CARIBBEAN SEA WITH SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS WITHIN 30 NM EITHER SIDE OF THE LINE. THE 
REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A 
SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED NEAR 28N24W.

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

$$

GARCIA