000 AXNT20 KNHC 311730 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE COAST LIBERIA NEAR 05N09W WESTWARD ALONG 2N20W 3N30W 2N40W EQ50W. CLUSTERS OF SCATTERED WEAK CONVECTION ARE FROM THE EQUATOR TO 06N BETWEEN 24W AND 38W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM OFF THE COAST OF LIBERIA AND COTE D'IVOIRE BETWEEN 4W AND 10W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES DRY SW FLOW ALOFT ACROSS THE BASIN...WITH AN UPPER LEVEL LONGWAVE MOVING NE ACROSS SOUTHERN TEXAS AND CENTRAL ARKANSAS. THIS FEATURE SUPPORTS THE NEXT COLD FRONT CURRENTLY OVER SE TEXAS AND SOON TO TO ENTER THE NW GULF WATERS OVER THE NEXT FEW HOURS. SATELLITE DERIVED WINDS AND SFC OBS ACROSS THE GULF INDICATE 15 KT TO 25 KT RETURN FLOW OVER MOST OF THE WESTERN HALF OF THE BASIN W OF 90W...BECOMING NEAR GALE FORCE RETURN FLOW N OF 25N BETWEEN 87W AND 92W. MOSTLY SSE FLOW IS OBSERVED E OF 90W DUE TO ANTI-CYCLONIC FLOW AROUND THE 1025 MB HIGH OVER THE WESTERN ATLC. THIS SCENARIO IS ADVECTING A WARM AND MOIST AIRMASS ACROSS THE N CENTRAL BASIN N OF 25N BETWEEN 85W AND 95W. IN RESPONSE...MOSAIC DOPPLER RADAR IMAGERY INDICATES SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS QUICKLY MOVING INLAND INTO LOUISIANA...MISSISSIPPI...AND ALABAMA BETWEEN 87W AND 92W. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. EXPECT CONVECTION TO CONTINUE TO DEVELOP ACROSS MOST OF THE GULF...AHEAD OF THE COLD FRONT IN THE NEXT 24 HOURS. CARIBBEAN SEA... THE SURFACE RIDGE OVER THE W ATLC COVERS A GREAT PORTION OF THE NORTHERN HALF OF THE CARIBBEAN PROVIDING 15-20 KT ANTI-CYCLONIC FLOW N OF 14N. A DISSIPATING STATIONARY FRONT EXTENDS ACROSS THE CENTRAL ATLC...ENTERING THE EASTERN CARIBBEAN AS A REMNANT CLOUD/SHEAR LINE ACROSS THE LEEWARD ISLANDS NEAR DOMINICA TO 14N71W. LOW LEVEL CONFLUENCE BETWEEN NE WINDS AND TRADEWINDS ALONG THE SHEAR LINE ARE GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 55 NM ON EITHER SIDE OF THE SHEAR AXIS. TRADE WINDS MOVING ACROSS THE SE CARIBBEAN ARE BANKING SOME LOW LEVEL MOISTURE...PROVIDING FOCUS FOR SCATTERED SHOWERS WITHIN 40 NM OFF THE COAST OF PANAMA AND COSTA RICA BETWEEN 80W-84W. THE UPPER LEVELS OF THE CARIBBEAN ARE DOMINATED BY A BROAD UPPER LEVEL RIDGE GIVING THE CARIBBEAN A DRY SW FLOW ALOFT...PROVIDING FAIR WEATHER CONDITIONS TO THE REMAINDER OF THE BASIN. ATLANTIC OCEAN... A DISSIPATING BOUNDARY ENTERS THE DISCUSSION AREA AS A COLD FRONT NEAR 32N28W...EXTENDING SW ALONG TO 23N40W...BECOMING STATIONARY TO 16N60W. SCATTERED SHOWERS ARE WITHIN 40 NM ON EITHER SIDE OF THE DISSIPATING COLD FRONT N OF 23N...WHILE ISOLATED SHOWERS ARE WITHIN 20 NM EITHER SIDE OF THE DISSIPATING STATIONARY FRONT. THIS SYSTEM HAS LOST ITS UPPER LEVEL SUPPORT AND IT IS EXPECTED TO CONTINUE TO WEAKEN OVER THE NEXT 24 HOURS. HOWEVER...A SECOND ROUND OF COLD AIR ADVECTION IS BEHIND THIS BOUNDARY...ANALYZED AS A COLD FRONT EXTENDING ALONG 32N40W 27N48W 25N57W. THIS FRONT IS SUPPORTED ALOFT BY A RATHER FAST MOVING SHORTWAVE EMBEDDED IN AN AREA OF DIFFLUENCE NOTED ON WATER VAPOR IMAGERY FROM 30N TO 40N BETWEEN 34W AND 44W. SCATTERED SHOWERS ARE WITHIN 85 NM AHEAD OF THE FRONT N OF 27N. SURFACE RIDGING IS ELSEWHERE ACROSS THE WESTERN AND EASTERN REGIONS OF THE ATLC ANCHORED BY A 1025 MB HIGH NORTHEAST OF THE BAHAMAS NEAR 29N76W AND A 1022 MB HIGH N OF THE CANARY ISLANDS NEAR 31N17W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA