000
AXNT20 KNHC 140553
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED DEC 14 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N11W TO 
08N18W TO 06N30W TO 07N37W TO 06N45W. NO SIGNIFICANT DEEP 
CONVECTION IS NOTED ON SATELLITE IMAGERY.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE REMAINS IN CONTROL OVER THE ENTIRE GULF 
BASIN THIS EVENING WITH WATER VAPOR IMAGERY INDICATING MOSTLY 
DRY AND STABLE CONDITIONS ALOFT. AT THE SURFACE...A RIDGE AXIS 
EXTENDS FROM THE EASTERN CONUS SOUTHWARD INTO THE GULF FROM THE 
FLORIDA PANHANDLE NEAR 31N86W TO THE SW GULF NEAR 20N96W. EAST 
TO SOUTHEASTERLY WINDS IN THE RANGE OF 15 TO 25 KT ARE NOTED ON 
RECENT SHIP...BUOY...AND OFFSHORE OIL PLATFORMS...AS WELL AS AN 
ASCAT PASS AROUND 14/0218 UTC. THE RIDGE IS FORECAST TO 
GRADUALLY SHIFT EASTWARD AS A VIGOROUS UPPER LEVEL TROUGH 
CURRENTLY ACROSS THE FOUR CORNERS REGION MOVES SLOWLY EASTWARD. 
EJECTED PROGRESSIVE SHORTWAVE ENERGY FROM THE TROUGH IS EXPECTED 
TO MOVE NE ACROSS THE SOUTHERN PLAINS AND INTRODUCE A WEAK 
FRONTAL BOUNDARY TO THE NW GULF LATE THURSDAY INTO EARLY FRIDAY. 
THE FRONT IS FORECAST TO STALL OVER THE NORTHERN GULF WATERS AND 
DISSIPATE OVER THE WEEKEND.

CARIBBEAN SEA...
AN UPPER LEVEL RIDGE INFLUENCES MUCH OF THE CARIBBEAN THIS 
EVENING WITH AN AXIS EXTENDING FROM OVER VENEZUELA NEAR 06N63W 
NORTHWESTWARD TO OVER THE YUCATAN CHANNEL NEAR 21N86W. ON THE 
WESTERN PERIPHERY OF THE RIDGE W OF 70W...SOUTHERLY DIFFLUENT 
FLOW ALOFT CONTINUES TO PROVIDE ENHANCEMENT TO ISOLATED SHOWERS 
AND TSTMS S OF 14N BETWEEN 77W-86W...INCLUDING PORTIONS OF 
PANAMA...COSTA RICA...AND NICARAGUA. MOST OF THIS CONVECTIVE 
ACTIVITY IS FOCUSED IN THE VICINITY OF THE MONSOON TROUGH AXIS 
WHICH EXTENDS FROM THE E PACIFIC ALONG 09N TO NORTHERN COLOMBIA. 
OTHERWISE...NE TRADES ARE EXPECTED TO REMAIN STRONGEST OVER THE 
WESTERN CARIBBEAN THROUGH THURSDAY AND SPREAD EASTWARD AS 
STRONGER SURFACE HIGH PRESSURE BUILDS IN ACROSS THE SW NORTH 
ATLC WATERS FRIDAY REMAINING NEARLY STATIONARY OVER THE WEEKEND.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY ACROSS THE 
WESTERN NORTH ATLC WITH AXIS EXTENDING INTO THE DISCUSSION AREA 
ALONG 32N63W TO 24N72W. THIS UPPER LEVEL FEATURE SUPPORTS A COLD 
FRONT ANALYZED FROM 32N60W TO 26N65W TO 24N73W. WHILE THE FRONT 
LACKS ANY SIGNIFICANT CONVECTION IN ITS VICINITY...A PRE-FRONTAL 
TROUGH EXTENDS FROM NEAR 30N59W TO 20N63W WITH SCATTERED SHOWERS 
AND ISOLATED TSTMS OCCURRING FROM 20N TO 32N BETWEEN 54W-60W... 
AND ISOLATED SHOWERS OCCURRING FARTHER SOUTH FROM 12N-20N 
BETWEEN 43W-58W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE 
INFLUENCE OF NW FLOW ALOFT AND RELATIVELY STABLE CONDITIONS NW 
OF THE COLD FRONT. MOSTLY BRISK N-NE WINDS ARE NOTED ON A RECENT 
ASCAT PASS AND FAST MOVING ISOLATED SHOWERS ARE POSSIBLE THROUGH 
THE OVERNIGHT HOURS. ELSEWHERE EAST OF 50W...A SURFACE RIDGE 
REMAINS IN PLACE ANCHORED BY A 1030 MB HIGH CENTERED NEAR 33N30W.

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

$$
HUFFMAN