000 AXNT20 KNHC 040539 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE DEC 04 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF SIERRA LEONE. THE ITCZ BEGINS AT THE COAST NEAR 7N13W AND CONTINUES ALONG 4N26W 6N40W TO 9N48W. A SURFACE TROUGH EXTENDS FROM 18N49W TO 8N51W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 210 NM N OF THE ITCZ BETWEEN 26W-34W AND WITHIN 60 NM OF LINE FROM 2N34W TO 3N38W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM ALONG THE COAST OF SW AFRICA S OF 7N W OF 5W AND WITHIN 90 NM EITHER SIDE OF THE ITCZ BETWEEN 33W-43W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE CONTINUES TO DOMINATE THE GULF TONIGHT ANCHORED BY A 1027 MB HIGH OFF THE COAST OF SOUTH CAROLINA. AN UPPER RIDGE IS BEING INDUCED OVER THE W GULF ALONG 93W IN RESPONSE TO AN UPPER TROUGH DIGGING S FROM THE PLAIN STATES INTO N MEXICO. SOUTHERLY RETURN FLOW OVER THE NW GULF CONTINUES TO PRODUCE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 45 NM OF LINE FROM 27N94W TO OVER LAKE CHARLES LOUISIANA. REMNANT MOISTURE IS GENERATING SCATTERED SHOWERS FROM 23N-27N BETWEEN 86W-92W. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES TONIGHT. THE SURFACE RIDGE WILL SHIFT E THROUGH TODAY. A WEAK FRONT WILL MOVE INTO THE NW GULF TUE NIGHT STALLING OVER THE CENTRAL GULF WED AND DISSIPATING THU. HIGH PRESSURE REBUILDS ACROSS THE GULF FROM THE NE FRI AND SAT. CARIBBEAN SEA... A BROAD UPPER RIDGE IN THE TROPICAL ATLC EXTENDS A RIDGE AXIS ALONG THE N COAST OF SOUTH AMERICA TO OVER S NICARAGUA NEAR 11N84W GIVING THE CARIBBEAN MAINLY SW TO W FLOW ALOFT. MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR ALOFT DOMINATE THE CARIBBEAN TONIGHT. LIGHT TO MODERATE NE TRADE WINDS ACROSS THE CARIBBEAN CONTINUE TO BANK LOW CLOUDS WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS IN THE GULF OF HONDURAS S OF 19N W OF 85W AND WITHIN 120 NM ALONG THE COAST OF NICARAGUA. REMNANT LOW LEVEL MOISTURE IS GENERATING SCATTERED SHOWERS OVER THE NE CARIBBEAN FROM 17N-20N BETWEEN THE VIRGIN ISLANDS AND DOMINICAN REPUBLIC AND OVER THE SE CARIBBEAN S OF 13N E OF 64W TO OVER THE WINDWARD ISLANDS. THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY CLEAR SKIES TONIGHT. THE TRADE WINDS WILL PREVAIL THROUGH WED. ATLANTIC OCEAN... A SURFACE RIDGE DOMINATES MOST OF THE W ATLC ANCHORED BY A 1027 MB HIGH OFF THE COAST OF SOUTH CAROLINA. AN UPPER TROUGH IS DIGGING S INTO THE W/CENTRAL ATLC REINFORCING THE SHORTWAVE UPPER TROUGH EXTENDS FROM 31N57W TO 23N55W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 27N55W THROUGH A 1011 MB LOW NEAR 21N58W TO 18N58W. AN UPPER RIDGE IS TO THE E EXTENDING FROM 22N45W TO 33N35W PROVIDING DIFFLUENCE ALOFT TO GENERATE DENSE CLOUD COVER WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-33N BETWEEN 38W-56W. AN UPPER TROUGH IS N OF THE DISCUSSION AREA SUPPORTING A COLD FRONT THAT EXTENDS THROUGH 32N37W TO 29N39W WHERE A SURFACE TROUGH CONTINUES ALONG 25N42W TO 21N45W. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE E ATLC N OF 14N E OF 36W ANCHORED BY A 1036 MB HIGH E OF THE AZORES. FRESH TO STRONG NE WINDS WILL PERSIST S OF 25N TODAY. WINDS WILL DIMINISH S OF 25N WED AS THE W ATLC SURFACE RIDGE WEAKENS. A WEAK COLD FRONT WILL CLIP THE AREA N OF 30N LATE WED AND THU WITH HIGH PRESSURE REBUILDING FRI AND SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW