000 AXNT20 KNHC 030543 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST MON DEC 03 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 INTO THE E TROPICAL ATLC NEAR 9N13W CONTINUING TO 7N18W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N23W TO 6N34W THEN RESUMES NEAR 6N39W TO 9N48W THEN RESUMES NEAR 8N53W TO SOUTH AMERICA NEAR 9N61W. THE BREAKS IN THE ITCZ ARE DUE TO A PAIR OF SURFACE TROUGHS. THE EASTERN SURFACE TROUGH EXTENDS FROM 10N32W TO 6N37W AND THE WESTERN SURFACE TROUGH EXTENDS FROM 13N47W TO 8N52W. SCATTERED MODERATE CONVECTION IS WITHIN 45 NM OF LINE FROM 2N31W TO 3N34W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE S OF 11 TO INLAND OVER SOUTH AMERICA BETWEEN 55W-61W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE DOMINATES THE GULF TONIGHT ANCHORED BY A 1028 MB HIGH OFF THE COAST OF NORTH CAROLINA WITH NEAR ZONAL WESTERLY FLOW ALOFT. SOUTHERLY RETURN FLOW OVER THE NW GULF IS PRODUCING SCATTERED SHOWERS WITHIN 60 NM OF LINE FROM 25N93W TO NEAR GALVESTON TEXAS AND INCLUDES A PORTION OF SW LOUISIANA. EASTERLY WINDS OVER THE SE GULF ARE GENERATING SCATTERED SHOWERS FROM 25N TO THE COAST OF CUBA E OF 85W INTO THE STRAITS OF FLORIDA. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES TONIGHT. THE SURFACE RIDGE WILL GRADUALLY SHIFT E THROUGH TUE. A WEAK FRONT WILL MOVE INTO THE NW GULF EARLY WED STALLING IN THE CENTRAL GULF LATE WED INTO EARLY THU AND DISSIPATING LATE THU AS HIGH PRESSURE REBUILDS IN FROM THE NE THROUGH FRI. CARIBBEAN SEA... A BROAD UPPER RIDGE IN THE TROPICAL ATLC IS GIVING THE CARIBBEAN MAINLY SW TO W FLOW ALOFT. MODERATE NE TRADE WINDS ACROSS THE CARIBBEAN ARE BANKING LOW CLOUDS WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS IN THE GULF OF HONDURAS S OF 19N W OF 84W...IN THE SW CARIBBEAN TO INLAND OVER W PANAMA/COSTA RICA AND WITHIN 45 NM ALONG THE COAST S OF 11N W OF 80W...AND N OF 16N BETWEEN 64W-72W INCLUDING THE VIRGIN ISLANDS TO THE DOMINICAN REPUBLIC. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER TONIGHT. THE TRADE WINDS WILL PREVAIL THROUGH WED. ATLANTIC OCEAN... A SURFACE RIDGE DOMINATES MOST OF THE W ATLC ANCHORED BY A 1026 MB HIGH OFF THE COAST OF NORTH CAROLINA. A SHORTWAVE UPPER TROUGH EXTENDS FROM AN UPPER LOW NEAR 31N62W SW TO 21N67W WITH AN UPPER RIDGE TO THE E ALONG 50W BETWEEN 20N-31N AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE DENSE CLOUD COVER WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 21N-30N BETWEEN 50W-62W. A SURFACE TROUGH IS NEAR THE BASE OF THE UPPER TROUGH EXTENDING FROM 25N61W TO 20N68W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM E OF THE TROUGH AXIS AND S OF 20N TO OVER THE GREATER ANTILLES BETWEEN THE VIRGIN ISLAND AND THE DOMINICAN REPUBLIC. A SHARP UPPER TROUGH EXTENDS THROUGH 32N40W TO 22N37W SUPPORTING A 1006 MB LOW NEAR 32N42W WITH A SURFACE TROUGH EXTENDING S TO 25N44W. A SHARP UPPER RIDGE IS JUST TO THE E ALONG 30W/31W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM 20N35W TO BEYOND 32N37W. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE E ATLC N OF 15N E OF 35W ANCHORED BY A 1033 MB HIGH E OF THE AZORES. THE SURFACE TROUGH WILL MOVE E THROUGH TUE. A WEAK COLD FRONT MAY CLIP THE WATERS N OF 30N LATE WED AND THU WITH HIGH PRES REBUILDING IN FROM THE N ON FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW