000 AXNT20 KNHC 021148 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI DEC 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W TO 9N19W. THE ITCZ EXTENDS FROM 9N19W ALONG 4N27W 9N41W TO SOUTH AMERICA NEAR 5N56W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 4N-9N BETWEEN 17W-26W AND FROM 5N-13N BETWEEN 32W-47W. ...DISCUSSION... GULF OF MEXICO... NEAR ZONAL WESTERLY FLOW ALOFT PREVAILS ACROSS THE ENTIRE GULF. DRY STABLE AIR AND STRONG SUBSIDENCE CONTINUES TO DOMINATE THE GULF E OF 94W. ISOLATED SHOWERS ARE INLAND AND WITHIN 45 NM ALONG THE COAST OF CUBA BETWEEN 81W-83W. SCATTERED COLD AIR CLOUDS DOT THE GULF BUT MOSTLY FAIR WEATHER PREVAILS THIS MORNING. A SURFACE RIDGE COVERS THE GULF AND THE SE CONUS ANCHORED BY A 1029 MB HIGH OVER E MISSISSIPPI AND A SECOND 1029 MB HIGH OVER SOUTH CAROLINA. SURFACE RIDGE WILL SHIFT E THROUGH SUN IN ADVANCE OF A COLD FRONT EXPECTED TO MOVE INTO THE NW GULF SUN EVENING. THE FRONT WILL REACH FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE TUE. CARIBBEAN SEA... THE SHEAR LINE THAT WAS OVER THE W CARIBBEAN HAS DISSIPATED. A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN W OF A NARROW UPPER TROUGH THAT EXTENDS FROM THE N LEEWARD ISLANDS NEAR 18N62W TO BONAIRE IN THE ABC ISLANDS. DRY STABLE AIR ALOFT AND STRONG SUBSIDENCE COVERS THE CARIBBEAN W OF THE UPPER TROUGH WITH MOIST AIR ALOFT TO THE SE. A SURFACE TROUGH IS OVER THE LESSER ANTILLES EXTENDING FROM 20N58W ACROSS MARTINIQUE INTO THE SE CARIBBEAN JUST W OF THE WINDWARD ISLANDS TO THE COAST OF VENEZUELA NEAR 11N62W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS E OF THE UPPER TROUGH AXIS ACROSS THE LESSER ANTILLES AND WITHIN 150/180 NM E OF THE SURFACE TROUGH INTO THE W TROPICAL ATLC. ISOLATED SHOWERS REMAIN POSSIBLE ACROSS THE REMAINDER OF THE CARIBBEAN. THE MONSOON TROUGH IS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 11N75W INTO THE E PACIFIC OVER PANAMA/COSTA RICA NEAR 9N83W. STRONG SURFACE RIDGE OVER THE SE CONUS WILL SHIFT E AND BUILD THROUGH SUN THEN SHIFT NE WHILE WEAKENING EARLY NEXT WEEK. SURFACE TROUGH OVER THE LESSER ANTILLES WILL SLOWLY MOVE W ACROSS THE E CARIBBEAN THROUGH MON. ATLANTIC OCEAN... A SURFACE RIDGE CONTINUES TO BUILD OVER THE W ATLC FROM THE SE CONUS AND GULF OF MEXICO. BROAD UPPER TROUGH COVERS THE W ATLC N OF 22N W OF 55W WITH A SURFACE TROUGH EMBEDDED ALONG 29N67W ACROSS THE TURKS AND CAICOS TO 20N73W. ISOLATED SHOWERS ARE N OF 26N BETWEEN 64W-71W. A COLD FRONT REMAINS IN THE CENTRAL ATLC SUPPORTED BY AN UPPER TROUGH WELL N OF THE DISCUSSION AREA ENTERING THE REGION NEAR 32N55W TO 24N56W. DRY STABLE AIR AND STRONG SUBSIDENCE COVERS THE W ATLC W OF 56W WITH THE EXCEPTION OF N OF 26N BETWEEN 64W-71W. A NARROW HIGH AMPLITUDE UPPER RIDGE IS IN THE CENTRAL ATLC EXTENDING AN AXIS FROM 20N52W TO BEYOND 32N51W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 20N54W TO BEYOND 32N55W. AN UPPER TROUGH COVERS THE E ATLC N OF 20N E OF 40W WITH AN UPPER LOW NEAR 30N32W AND SUPPORTING A 1018 MB LOW NEAR 31N27W WITH A SURFACE TROUGH EXTENDING S FROM THE LOW ALONG 27N29W THEN W TO 24N36W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 27N BETWEEN 25N-33W. A SURFACE RIDGE COVERS THE REMAINDER OF THE CENTRAL/E ATLC N OF 20N E OF 50W WITH A WEAKNESS IN THE VICINITY OF THE ABOVE LOW/TROUGH AND ANCHORED BY A 1037 MB HIGH N OF THE AZORES. W ATLC SURFACE RIDGE WILL CONTINUE TO BUILD E ACROSS THE W ATLC THROUGH WEEKEND THEN SHIFT NE AND WEAKEN EARLY NEXT WEEK. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW