000 AXNT20 KNHC 051746 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 05 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 07N12W TO 05N19W TO 06N36W TO 04N51W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 02N-09N BETWEEN 30W-50W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE SW GULF NORTHEASTWARD OVER THE FLORIDA PENINSULA TO BEYOND 32N78W. THIS UPPER LEVEL FEATURE CONTINUES TO SUPPORT A LARGE AND STRETCHED 1033 SURFACE HIGH CENTERED WELL NE OF THE AREA OFF THE COAST OF NEW ENGLAND 41N62W. THE SURFACE RIDGE AXIS EXTENDS SW ALONG THE EASTERN SEABOARD...EXTENDING OVER MUCH OF THE GULF E OF 90W. MODERATE TO FRESH E TO SE WINDS ARE EXPECTED THROUGH THE AFTERNOON AND EVENING HOURS ON THE SOUTHWESTERN PERIPHERY OF THE HIGH. AN UPPER LEVEL TROUGH CURRENTLY LOCATED OVER THE FOUR CORNERS REGION AND AN ASSOCIATED SHORTWAVE MOVING ACROSS TEXAS IS SUPPORTING A COLD FRONT EXTENDING INTO THE GULF FROM PORT ARTHUR TEXAS TO 24N98W. STRONG NORTHERLY WINDS IN THE RANGE OF 20 TO 25 KT ARE OBSERVED WEST OF THE FRONT WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. THE FRONT IS FORECAST TO SLOWLY MOVE EASTWARD THROUGH THE WEEK AND CLEAR EAST OF THE GULF REGION LATE THURSDAY INTO EARLY FRIDAY AS HIGH PRESSURE BUILDS ACROSS THE SOUTHERN PLAINS AND NW GULF OVER THE WEEKEND. CARIBBEAN SEA... AN UPPER LEVEL TROUGH EXTENDS SOUTHWARD FROM THE SW NORTH ATLC INTO THE CENTRAL CARIBBEAN WITH AXIS FROM OVER THE MONA PASSAGE NEAR 19N68W TO A BASE OVER NORTHERN COLOMBIA AND NW VENEZUELA NEAR 09N73W. WEST OF THE UPPER LEVEL TROUGH WATER VAPOR IMAGERY INDICATES VERY DRY AND STABLE NORTHWESTERLY FLOW ALOFT PROVIDING MUCH OF THE WESTERN CARIBBEAN W OF 68W WITH FAIR SKIES THIS AFTERNOON. AT THE SURFACE...NE WINDS ARE NOTED ON SHIP AND BUOY OBSERVATIONS WITH LOW-LEVEL MOISTURE CONVERGENCE SUPPORTING ISOLATED SHOWERS ALONG THE COAST OF NICARAGUA...COSTA RICA...AND WESTERN PANAMA. ANOTHER AREA OF POSSIBLE ISOLATED SHOWERS IS OVER THE NW CARIBBEAN FROM 18N-20N BETWEEN 79W-87W. FARTHER EAST...THE UPPER LEVEL TROUGHING IS PROVIDING AMPLE MIDDLE TO UPPER LEVEL DIFFLUENCE GENERATING AN AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 150 NM EITHER SIDE OF A LINE FROM 11N67W TO 18N62W...INCLUDING THE LEEWARD ISLANDS. OVER THE NEXT FEW DAYS...THE UPPER LEVEL TROUGH ACROSS THE CENTRAL CARIBBEAN WILL BE SLOW TO MAKE ANY SIGNIFICANT PROGRESS EASTWARD SO FAIR WEATHER IS EXPECTED TO CONTINUE OVER WESTERN PORTIONS OF THE BASIN...WHILE CONTINUED INCREASED CHANCES FOR PRECIPITATION WILL LINGER OVER EASTERN PORTIONS OF THE BASIN THROUGH THURSDAY. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG 32N58W TO 19N69W AND INTO THE CENTRAL CARIBBEAN SEA. THIS TROUGHING SUPPORTS A SURFACE TROUGH ANALYZED FROM 17N60W TO 28N63W. LOW-LEVEL CONVERGENCE IS MAXIMIZED EAST THE SURFACE FEATURE WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 15N-30N BETWEEN 52W-63W. 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 GALE FORCE CONDITIONS CONFINED N OF 27N BETWEEN 60W AND 69W WHERE THE PRESSURE GRADIENT IS STRONGEST. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 30N31W BUT HAS MINIMAL IMPACT AT THE SURFACE AS A RIDGE...ANCHORED BY A 1035 MB HIGH CENTERED OVER THE AZORES NEAR 38N25W...CONTINUES TO INFLUENCE MUCH OF THE EASTERN ATLC E OF 45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN