000
AXNT20 KNHC 041751
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST SUN DEC 04 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ/MONSOON TROUGH...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N11W TO 
04N22W TO 05N52W. ISOLATED MODERATE CONVECTION IS WITHIN 45 NM 
EITHER SIDE OF A LINE FROM 03N26W TO 03N34W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE SW GULF NORTHEASTWARD 
OVER NORTHERN FLORIDA AND ALONG THE EASTERN U.S. SEABOARD TO 
BEYOND 32N80W. THIS UPPER LEVEL FEATURE CONTINUES TO SUPPORT A 
FAIRLY LARGE AND STRETCHED 1039 SURFACE HIGH PRESSURE AREA 
CENTERED WELL NE OF THE AREA OFF THE COAST OF NOVA SCOTIA NEAR 
43N63W. THE SURFACE RIDGE AXIS EXTENDS SW ALONG THE EAST COAST 
OF THE US...INFLUENCES MUCH OF THE SE CONUS E OF 90W AND EXTENDS 
OVER MUCH OF THE GULF TO A 1020 MB HIGH CENTERED OVER CENTRAL 
MEXICO NEAR 20N98W. MODERATE TO FRESH E TO SE WINDS ARE EXPECTED 
TO PERSIST ON THE SOUTHERN PERIPHERY OF THE HIGH THROUGH MONDAY 
MORNING. AN UPPER LEVEL TROUGH CURRENTLY MOVING ACROSS ARIZONA 
AND NORTHWESTERN MEXICO IS EXPECTED TO SUPPORT THE NEXT COLD 
FRONT FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA COAST BY 
MONDAY MORNING INTO THE AFTERNOON WITH STRONG NORTHERLY WINDS IN 
THE RANGE OF 20 TO 25 KT EXPECTED WEST OF THE FRONT.

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH EXTENDS SOUTHWARD FROM THE SW NORTH ATLC 
INTO THE CENTRAL CARIBBEAN WITH AXIS FROM OVER HISPANIOLA NEAR 
20N70W TO A BASE OVER NORTHERN COLOMBIA AT 20N75W. WEST OF THE 
UPPER LEVEL TROUGH NORTHWESTERLY DRY AND STABLE FLOW ALOFT 
DOMINATES WHICH IS PROVIDING MUCH OF THE WESTERN CARIBBEAN W OF 
70W WITH FAIR SKIES THIS AFTERNOON. AT THE SURFACE...NE WINDS 
ARE NOTED IN THE RANGE OF 15 TO 25 KT WITH LOW-LEVEL MOISTURE 
CONVERGENCE SUPPORTING ISOLATED SHOWERS ALONG THE COAST OF 
CENTRAL AMERICA...INCLUDING THE GULF OF HONDURAS AND PORTIONS OF 
THE SW CARIBBEAN W OF 80W. SOME OF THIS MOISTURE AND CLOUDINESS 
CONTINUES TO ADVECT ONSHORE AND PROVIDE ISOLATED SHOWER ACTIVITY 
FOR INLAND PORTIONS OF BELIZE...HONDURAS...AND NICARAGUA. 
FARTHER EAST...THE UPPER LEVEL TROUGHING SUPPORTS A SURFACE 
TROUGH EXTENDING FROM THE CENTRAL ATLC INTO THE NE CARIBBEAN 
ALONG 20N63W TO 14N63W. THE LOW-LEVEL CONVERGENCE ASSOCIATED 
WITH THE SURFACE TROUGH AND AMPLE UPPER LEVEL DIFFLUENCE 
PROVIDED BY THE MIDDLE TO UPPER LEVEL TROUGH IS GENERATING A 
BROAD AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS E OF A 
LINE FROM EASTERN PUERTO RICO NEAR 18N66W TO THE GUAJIRA 
PENINSULA IN NORTHERN COLOMBIA. WITH THE SURFACE TROUGH NEARLY 
STATIONARY OVER THE PAST 24 HOURS...PRECIPITATION AMOUNTS 
REPORTED BY GUADELOUPE...TRINIDAD...AND CURACAO WERE IN THE 0.5 
TO 1.0 INCH RANGE. BY TUESDAY...THE TROUGHING IS EXPECTED TO 
WEAKEN AS HIGH PRESSURE CURRENTLY OVER THE SW NORTH ATLC SHIFTS 
EASTWARD.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG 32N62W TO 20N70W AND 
INTO THE CENTRAL CARIBBEAN SEA. THIS TROUGHING SUPPORTS A 
SURFACE TROUGH ANALYZED FROM 30N59W TO 18N63W. LOW-LEVEL 
CONVERGENCE IS MAXIMIZED IN THE VICINITY OF THE SURFACE FEATURE 
WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 360 
NM EAST...AND 180 NM WEST OF THE AXIS. TO THE WEST OVER THE 
REMAINDER OF THE SW NORTH ATLC...NE TO E WINDS CONTINUE IN THE 
RANGE OF 20 TO 30 KT WITH POSSIBLE QUICK-MOVING ISOLATED SHOWERS 
OCCURRING ACROSS THE BAHAMAS AND NEAR THE EAST COAST OF FLORIDA 
AND GEORGIA THIS AFTERNOON INTO THE EVENING. FARTHER EAST...AN 
UPPER LEVEL LOW IS CENTERED NEAR 29N39W AND SUPPORTS A WEAK 
SURFACE TROUGH AT THE SURFACE ANALYZED FROM 23N40W TO 29N45W. 
MOST OF THE LOW TO MIDDLE LEVEL MOISTURE CONVERGENCE IS LOCATED 
TO THE EAST OF THE SURFACE TROUGH WITH WIDELY SCATTERED SHOWERS 
OCCURRING OVER THE AREA FROM 22N-31N BETWEEN 31W-41W. MUCH OF 
THIS ACTIVITY IS LIKELY ENHANCED DUE TO THE UPPER LEVEL LOW AND 
THE ASSOCIATED UPPER LEVEL DIFFLUENCE. OTHERWISE...A RIDGE 
INFLUENCES THE REMAINDER OF THE EASTERN ATLC ANCHORED BY A 1036 
MB HIGH CENTERED OVER THE AZORES NEAR 38N25W.

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

$$
HUFFMAN