000 AXNT20 KNHC 241723 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 24 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... ITCZ AXIS EXTENDS FROM S OF LIBERIA NEAR 4N8W ALONG 2N24W 3N43W EQ50W. ISOLATED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 25W-51W. ...DISCUSSION... GULF OF MEXICO... MAINLY ZONAL WLY FLOW ALOFT COVERS THE GULF OF MEXICO S OF AN UPPER LEVEL RIDGE MOVING ACROSS THE ERN CONUS. WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR ACCOMPANIES THE UPPER LEVEL FLOW PROVIDING MUCH OF THE BASIN WITH GENERALLY FAIR WEATHER. HOWEVER...AN AREA OF PATCHY LOW-MID LEVEL CLOUDS WITH POSSIBLE ISOLATED SHOWERS EXTENDS FROM THE YUCATAN PENINSULA TO THE TEXAS COASTLINE NEAR CORPUS CRISTI...REMNANTS OF A FRONTAL BOUNDARY THAT DISSIPATED AROUND 0600 UTC THIS MORNING. THE REMAINDER OF THE BASIN IS INFLUENCED BY SURFACE RIDGING EXTENDING FROM THE N PROVIDING 10-15 KT ANTI-CYCLONIC FLOW ACROSS THE AREA. EXPECT CONDITIONS ACROSS THE NW GULF TO DETERIORATE OVER THE NEXT 24 HOURS AS A VIGOROUS SHORTWAVE UPPER TROUGH CURRENTLY EXTENDING FROM THE UPPER MISSISSIPPI VALLEY TO THE SRN PLAINS PROGRESSES EWD SUPPORTING A STRONG COLD FRONT WHICH IS FORECAST TO MOVE OFF THE TEXAS COAST BY SATURDAY MORNING. THE FRONT IS CURRENTLY ACROSS CENTRAL TEXAS GENERATING STRONG SHOWERS WITH ISOLATED THUNDERSTORMS. STRONG NW-N WINDS UP TO 30 KT ARE FORECAST BEHIND THE FRONT AS IT MOVES OUT ACROSS THE GULF. CARIBBEAN SEA... DRY AIR AND SUBSIDENCE ALOFT THAT COVERS THE GULF OF MEXICO IS ALSO IMPACTING MUCH OF THE WRN CARIBBEAN KEEPING CONDITIONS FAIR. HOWEVER...ENHANCED AREAS OF MOISTURE ARE ACROSS THE SRN AND ERN PORTIONS OF THE BASIN. A SHEAR LINE EXTENDS FROM THE TROPICAL ATLC ACROSS THE WINDWARD ISLANDS NEAR MARTINIQUE AT 14N61W CONTINUING ALONG 13N69W 12N78W 9N81W. THE ENHANCED MOISTURE COMBINED WITH SURFACE WIND SPEED CONVERGENCE ALONG THE SHEAR LINE IS ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM NW OF THE AXIS BETWEEN 75W-84W...WITHIN 45 NM EITHER SIDE OF THE AXIS BETWEEN 68W-75W...AND FROM 12N-17N BETWEEN 61W-68W. ALOFT...MOIST SWLY FLOW COVERS THE ERN HALF OF THE BASIN AROUND THE WRN PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED N OF BRAZIL. EXPECT ENHANCED MOISTURE TO LINGER ACROSS THE SRN CARIBBEAN WITH SHOWER ACTIVITY LIKELY. ATLANTIC OCEAN... A BROAD DEEP LAYER TROUGH CONTINUES TO IMPACT THE MAJORITY OF THE ATLC W OF 40W. AN ASSOCIATED AND OCCLUDED 966 MB LOW REMAINS SPINNING OFF THE COAST OF NEWFOUNDLAND SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N47W REACHING SW ALONG 25N58W 21N70W AND ACROSS THE BAHAMAS TO THE STRAITS OF FLORIDA NEAR 24N80W. SCATTERED SHOWERS ARE WITHIN 100 NM AHEAD OF THE FRONT E OF 55W...AND WITHIN 75 NM AHEAD OF THE FRONT BETWEEN 55W-72W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE REMAINDER OF THE BOUNDARY. GALE FORCE WINDS ARE BEING MAINTAINED BOTH AHEAD AND BEHIND THE FRONT. REFER TO THE ATLANTIC HIGH SEAS FORECAST FOR MORE DETAILS. THE SAME LOW PRESSURE SYSTEM SUPPORTS A SURFACE TROUGH...REMNANTS OF A FRONTAL BOUNDARY ALONG 31N25W 25N33W 24N41W 22N45W. SCATTERED SHOWERS ARE N OF THE AXIS FROM 23N-28N BETWEEN 37W-44W. A SECOND SURFACE TROUGH EXTENDS ALONG 20N52W TO 14N54W SUPPORTING ISOLATED SHOWERS WITHIN 100 NM EITHER SIDE OF THE AXIS. A SHEAR AXIS ALSO EXTENDS FROM 16N57W TO THE WINDWARD ISLANDS NEAR MARTINIQUE SUPPORTING SCATTERED SHOWERS WITHIN 45 NM EITHER SIDE OF THE AXIS. ACROSS THE FAR ERN ATLC...AN UPPER LEVEL RIDGE EXTENDING FROM N OF BRAZIL NEAR 9N49W TO THE AZORES ISLANDS SUPPORTS A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH W OF THE CANARY ISLANDS NEAR 27N23W PROVIDING GENERALLY FAIR WEATHER ACROSS THIS PORTION OF THE BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON