000
AXNT20 KNHC 130538
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST THU JAN 13 2011

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 ANALYZED FROM 5N14W 2N22W 2N37W CROSSING THE 
EQUATOR NEAR 50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION ARE FROM 3N-6N BETWEEN 24W-35W AND FROM THE EQUATOR 
TO 5N BETWEEN 45W-52W. 

...DISCUSSION...

GULF OF MEXICO...
THE LARGE UPPER LEVEL LOW HAS SHIFTED TO OFF THE COAST OF NEW 
ENGLAND LEAVING THE GULF WITH SW FLOW ALOFT. THE ASSOCIATED COLD 
FRONT HAS EXITED THE GULF LEAVING COLD TEMPERATURES AND LOW DEW 
POINTS ACROSS THE GULF BASIN. BROKEN/OVERCAST LOW/MID CLOUDS 
WITH POSSIBLE ISOLATED SHOWERS REMAIN ACROSS THE S GULF S OF 
LINE FROM THE FLORIDA KEYS TO 22N92W. A SURFACE RIDGE DOMINATES 
THE GULF ANCHORED BY A STRONG 1043 MB HIGH OVER THE CENTRAL 
PLAIN STATES PRODUCING STRONG N TO NE SURFACE FLOW AND BANKING 
OVERCAST LOW CLOUDS ALONG THE E SLOPES OF THE SIERRA MADRE 
MOUNTAINS TO OVER THE W GULF W OF 92W. STRONG HIGH PRESSURE WILL 
PRODUCE STRONG N TO NE WINDS THROUGH THU MORNING THEN BEGIN TO 
DECREASE FROM NW TO SE THU THROUGH FRI MORNING. 

CARIBBEAN SEA...
A COLD FRONT ENTERS THE NW CARIBBEAN ACROSS CUBA FROM SAGUA LA 
GRANDE TO PUNTA GORDA ALONG 21N85W TO INLAND OVER THE YUCATAN 
PENINSULA NEAR 19N88W TO OVER N BELIZE WITH POSSIBLE ISOLATED 
SHOWERS WITHIN 60 NM EITHER SIDE OF THE FRONT AND STRONG NE 
WINDS BEHIND THE FRONT. BROAD UPPER RIDGE COVERS THE CARIBBEAN 
WITH THE RIDGE AXIS ANCHORED JUST E OF THE LESSER ANTILLES NEAR 
16N60W AND EXTENDS TO OVER PORTIONS OF THE W AND CENTRAL ATLC. 
FRESH/STRONG TRADE WINDS CONTINUE ACROSS THE CARIBBEAN DUE TO 
THE TIGHT PRESSURE GRADIENT OF THE LOWER PRESSURE OVER SOUTH 
AMERICA AND THE SURFACE RIDGE OVER THE W ATLC INTO THE CENTRAL 
ATLC. RESIDUAL MOISTURE IS PRODUCING CLUSTERS OF SCATTERED 
SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF 
LINE FROM 11N65W 17N75W TO OVER NICARAGUA AND HONDURAS NEAR 
15N87W. THIS SURFACE FLOW IS ALSO GENERATING A SURFACE TROUGH 
OVER THE SW CARIBBEAN EXTENDING FROM 11N79W TO ACROSS COSTA 
RICA/PANAMA BORDER INTO THE E PACIFIC REGION. THE REMAINDER OF 
THE CARIBBEAN HAS FAIR WEATHER AGAIN TONIGHT. THE COLD FRONT IS 
EXPECTED TO MOVE SE REACHING FROM CENTRAL CUBA TO THE N GULF OF 
HONDURAS LATER THIS MORNING THEN BECOME NEARLY STATIONARY AND 
DISSIPATE THROUGH LATE FRI.

ATLANTIC OCEAN...
LARGE UPPER LOW HAS MOVED OFF THE NEW ENGLAND COAST EXTENDING AN 
UPPER TROUGH OVER THE W ATLC SUPPORTING A COLD FRONT THAT ENTERS 
THE REGION 32N67W ALONG 26N73W ACROSS CUBA AND INTO THE 
CARIBBEAN NEAR SAGUA LA GRANDE. A WEAK PRE-FRONTAL SURFACE 
TROUGH EXTENDS THROUGH 32N64W TO 26N72W. ISOLATED SHOWERS ARE 
WITHIN 60 NM OF THE COLD FRONT. A BROAD UPPER TROUGH OVER THE 
CENTRAL ATLC EXTENDS S TO 20N BETWEEN 25W-45W SUPPORTING A 
WEAKENING COLD FRONT THAT ENTERS THE CENTRAL ATLC AS A 
DISSIPATING STATIONARY FRONT NEAR 32N29W TO 26N38W WHERE IT 
CONTINUES AS A SHEAR AXIS TO 24N53W. ISOLATED SHOWERS ARE WITHIN 
30 NM OF THE FRONT N OF 27N. SURFACE HIGH PRESSURE COVERS THE 
CENTRAL AND E ATLC N OF 15N E OF 65W WITH A 1026 MB HIGH NEAR 
30N48W WITH A WEAKNESS IN THE IMMEDIATE VICINITY OF THE ABOVE 
FRONT. 

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

$$
PAW