000
AXNT20 KNHC 150544
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST WED DEC 15 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 
0515 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 09N14W 08N35W 03N51W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 05N-10N BETWEEN 19W-28W... 
AND FROM 05N-08N BETWEEN 28W-39W. 

...DISCUSSION...

GULF OF MEXICO...
WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR IS PRESENT ALOFT 
OVER THE GULF WITH CONFLUENT W-NW FLOW PROVIDING FOR AN OVERALL 
STABLE ATMOSPHERE DURING THE OVERNIGHT HOURS. AT THE SURFACE...A 
BROAD SURFACE RIDGE REMAINS IN CONTROL ANCHORED BY A 1023 MB 
HIGH CENTERED OVER SOUTHERN ALABAMA. THE RIDGE IS FORECAST TO 
SLIDE EASTWARD AND INTO THE W ATLC BY THURSDAY WITH INCREASED 
S-SE WINDS EXPECTED OVER THE NW GULF WATERS TO PERSIST AHEAD OF 
THE NEXT FRONTAL BOUNDARY EXPECTED TO EMERGE OFF THE TEXAS COAST 
EARLY FRIDAY.

CARIBBEAN SEA...
VERY STRONG DRY AIR AND SUBSIDENCE ALOFT IS NOTED ACROSS THE NW 
CARIBBEAN THAT CONTINUES TO SUPPORT A SURFACE RIDGE THAT EXTENDS 
FROM THE SE CONUS AND GULF OF MEXICO OVER MUCH OF THE WESTERN 
CARIBBEAN W OF 75W. OVERALL STABLE CONDITIONS PERSIST AS A 
RESULT WITH BROKEN TO OVERCAST STRATOCUMULUS CLOUDS NOTED ON 
SHORTWAVE INFRARED SATELLITE IMAGERY THIS EVENING. OVER THE 
EASTERN AND CENTRAL CARIBBEAN...A COLD FRONT IS ANALYZED FROM 
EASTERN PUERTO RICO NEAR 18N66W TO 17N70W THEN BECOMES A 
DISSIPATING STATIONARY BOUNDARY ALONG 15N74W TO 11N75W. 
LOW-LEVEL CONVERGENCE IN VICINITY OF THE FRONT CONTINUES TO 
PROVIDE FOCUS FOR ISOLATED SHOWERS WITHIN 150 NM EITHER SIDE OF 
THE FRONTAL BOUNDARY. POSSIBLE ISOLATED SHOWERS LINGER EAST OF 
THE FRONT OVER THE REMAINDER OF THE EASTERN CARIBBEAN AND LESSER 
ANTILLES DUE TO LIGHT E-NE TRADE WIND FLOW.

ATLANTIC OCEAN...
BROAD UPPER LEVEL TROUGHING IS EVIDENT ON WATER VAPOR IMAGERY 
OVER THE W ATLC WATERS THIS EVENING REMAINING MAINLY N OF 24N 
AND W OF 60W THAT SUPPORTS A COLD FRONT THAT ENTERS THE 
DISCUSSION AREA NEAR 32N58W AND EXTENDS S-SW ALONG 26N60W TO NE 
PUERTO RICO NEAR 18N66W AND INTO THE CENTRAL CARIBBEAN SEA. 
SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 300 NM EAST OF 
THE FRONT N OF 23N AND LIKELY ENHANCED DUE TO DIFFLUENCE 
ASSOCIATED WITH AN UPPER LEVEL RIDGE AXIS ALONG 52W. ISOLATED 
SHOWERS ARE ALSO OCCURRING WITHIN 180 NM W OF THE FRONT FROM 
18N-30N...AND FROM 17N-23N BETWEEN THE FRONT AND 53W. FARTHER 
EAST...AN UPPER LEVEL TROUGH CONTINUES TO IMPACT MUCH OF THE 
EASTERN ATLC E OF 40W DRIVING A COMPLEX AREA OF LOW PRESSURE 
NORTH OF THE DISCUSSION AREA THAT EXTENDS A COLD FRONT ALONG 
32N24W 23N27W TO 18N35W. SCATTERED SHOWERS ARE ISOLATED TSTMS 
ARE FROM 25N-32N BETWEEN THE FRONT AND 21W. ISOLATED SHOWERS 
LINGER WITHIN 120 NM SE OF THE FRONT S OF 25N.

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

$$
HUFFMAN