000 AXNT20 KNHC 141147 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE DEC 14 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 10N31W 05N43W 02N51W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-12N BETWEEN 24W-35W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 43W-48W. ...DISCUSSION... GULF OF MEXICO... DRY AND SUBSIDENT NW UPPER LEVEL FLOW DOMINATES ACROSS THE GULF WEST OF UPPER LEVEL TROUGHING LOCATED OVER THE MID-ATLC STATES AND W ATLC N OF 26N. THIS UPPER LEVEL PATTERN SUPPORTS A SURFACE RIDGE THAT COVERS A MAJORITY OF GULF ANCHORED BY A 1027 MB HIGH CENTERED OVER NORTHERN MISSISSIPPI. NORTHERLY WINDS TO 20 KT ARE OCCURRING OVER THE EASTERN GULF THIS MORNING AND ARE EXPECTED TO GRADUALLY DIMINISH THROUGH LATE TUESDAY AS THE RIDGE SLIDES EASTWARD. LOOKING AHEAD...BY WEDNESDAY SOUTHERLY RETURN FLOW IS EXPECTED OVER THE WESTERN GULF AS ANOTHER FRONTAL TROUGH DEVELOPS OVER THE SE CONUS AND EASTERN TEXAS. GLOBAL MODELS INDICATE A COLD FRONT WILL THEN ENTER THE NW GULF WATERS BY LATE FRIDAY. CARIBBEAN SEA... AN UPPER LEVEL TROUGH IS EVIDENT ON WATER VAPOR IMAGERY ACROSS THE W ATLC THAT DIPS TO 26N AND SUPPORTS A STATIONARY FRONT THAT CROSSES HISPANIOLA AND INTO THE CENTRAL CARIBBEAN NEAR 18N73W THEN BECOMES A SHEAR LINE EXTENDING SW TO EASTERN PANAMA NEAR 09N78W. WEST OF THE SHEAR LINE...NORTHERLY LOW-LEVEL FLOW DOMINATES WITH ISOLATED SHOWERS POSSIBLE OVER THE NW CARIBBEAN N OF 14N W OF 77W. IN THE VICINITY OF THE STATIONARY FRONT AND SHEAR LINE...WIDELY SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE BOUNDARIES...INCLUDING INTERIOR PORTIONS OF HISPANIOLA. ELSEWHERE OVER THE REMAINDER OF THE CARIBBEAN... AN UPPER LEVEL ANTICYCLONE POSITIONED IN THE WESTERN TROPICAL ATLC EXTENDS A RIDGE AXIS ALONG 11N BETWEEN 54W-90W AND IS PROVIDING THE BASIN WITH SOUTHWESTERLY UPPER LEVEL FLOW. DIFFLUENCE ASSOCIATED WITH THE UPPER LEVEL RIDGING IS ENHANCING SCATTERED SHOWERS AND ISOLATED TSTMS OVER NORTHERN COLOMBIA AND THE ADJACENT COASTAL WATERS FROM 08N-12N BETWEEN 71W-76W... INCLUDING LAKE MARACAIBO. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH CONTINUES TO MOVE NORTH UP THE EASTERN SEABOARD OF THE U.S. WITH TROUGHING DIPPING TO 26N OVER THE W ATLC WATERS. WATER VAPOR IMAGERY THIS MORNING INDICATES THAT MOSTLY DRY AIR AND W-SW FLOW ALOFT DOMINATES W OF 63W. THIS TROUGHING SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N62W AND EXTENDS SW TO 23N67W THEN BECOMES STATIONARY TO HISPANIOLA NEAR 20N70W. LOW-LEVEL CONVERGENCE EAST OF THE FRONT IS GENERATING SCATTERED SHOWERS OVER A LARGE AREA FROM 18N-32N BETWEEN THE FRONT AND 58W. WEAK SURFACE CONVERGENCE IS ALSO MAXIMIZED NORTH OF THE LESSER ANTILLES GENERATING ISOLATED SHOWERS FROM 16N-20N BETWEEN 54W-62W. ACROSS THE CENTRAL ATLC... A SURFACE RIDGE EXTENDS ALONG 50W AND OVERALL FAIR CONDITIONS ARE EXPECTED BETWEEN 40W-58W. FARTHER EAST...AN UPPER LEVEL TROUGH REMAINS THE DRIVING UPPER LEVEL FEATURE FOR A 1002 MB SURFACE LOW CENTERED NEAR 32N27W. A COLD FRONT EXTENDS SW FROM THE LOW ALONG 26N30W TO 21N41W WITH SCATTERED SHOWERS OCCURRING WITHIN THE AREA FROM 22N-32N BETWEEN THE FRONT AND 20W. ISOLATED SHOWERS ARE ALSO OCCURRING IN ASSOCIATION WITH THE UPPER LEVEL TROUGHING NW OF THE COLD FRONT FROM 25N-32N BETWEEN 30W-38W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN