000 AXNT20 KNHC 061202 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE DEC 06 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 A PORTION OF AFRICA WITH THE ITCZ AXIS ENTERING THE E TROPICAL ATLC NEAR 10N14W CONTINUING ALONG 3N26W TO 8N46W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE WITHIN 215 NM N OF THE ITCZ AXIS BETWEEN 31N-46W AND WITHIN 180 NM S OF THE ITCZ AXIS BETWEEN 31W-42W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS MOVING FROM THE CENTRAL PLAIN STATES ACROSS THE MISSISSIPPI VALLEY AND INTO THE NW GULF WATERS SUPPORTING A COLD FRONT ENTERING THE GULF AT 06/0900 UTC FROM A 1015 MB LOW JUST N OF BILOXI MISSISSIPPI TO 26N92W WHERE IT BECOMES STATIONARY TO INLAND OVER MEXICO BETWEEN TUXPAN AND VERACRUZ CONTINUING NW ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. BROKEN/OVERCAST LOW/MID CLOUDS WITH SCATTERED SHOWERS COVER THE AREA W OF THE FRONT. A SURFACE RIDGE IS BUILDING W OF THE FRONT. THE SURFACE RIDGE ANCHORED IN THE W ATLC CONTINUES TO RETREAT EASTWARD AS THE FRONT MOVES ACROSS THE GULF WITH SOUTHERLY RETURN FLOW OVER THE E GULF AND ISOLATED SHOWERS S OF 24N BETWEEN 80W-85W AND WITHIN 75 NM OF LINE FROM 25N86W TO OVER THE N GULF COAST NEAR PANAMA CITY FLORIDA. THE REMAINDER OF THE UPPER LEVELS ARE DOMINATED BY AN UPPER RIDGE WITH AN AXIS EXTENDING FROM THE NE YUCATAN PENINSULA TO ACROSS S FLORIDA NEAR MIAMI INTO THE W ATLC. COLD FRONT WILL REACH FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE WED MORNING AND THEN MOVE SE OF THE AREA LATE WED. HIGH PRESSURE WILL CONTINUE TO BUILD IN THE WAKE OF THE FRONT. CARIBBEAN SEA... A NARROW UPPER TROUGH AXIS EXTENDS FROM THE CENTRAL ATLC THROUGH THE MONA PASSAGE ALONG 13N73W TO COSTA RICA NEAR 11N84W. VERY STRONG SUBSIDENCE AND DRY STABLE AIR ARE W OF A LINE FROM THE N LEEWARD ISLANDS NEAR 17N63W TO COLOMBIA NEAR 11N72W WHILE MOIST TROPICAL AIR IS TO THE E OF THIS LINE. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE IN THE MOIST SECTOR OF THE CARIBBEAN WHILE THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY FAIR CONDITIONS AGAIN THIS MORNING. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W INTO THE E PACIFIC REGION OVER PANAMA/COSTA RICA NEAR 10N84W WITH ISOLATED SHOWERS/THUNDERSTORMS S OF 9N TO INLAND OVER COLOMBIA AND E PANAMA. RAINS CONTINUE TO TRAIN ACROSS THE LESSER ANTILLES CONTINUING THE POTENTIAL FOR FLOODING ESPECIALLY IN MOUNTAINOUS REGIONS. A COLD FRONT WILL MOVE INTO THE FAR W CARIBBEAN WED NIGHT THEN STALL AND DISSIPATE OVER THE W CARIBBEAN THROUGH FRI. ATLANTIC OCEAN... THE UPPER RIDGE FROM THE GULF OF MEXICO EXTENDS AN AXIS ACROSS MIAMI FLORIDA INTO THE W ATLC TO BEYOND 32N72W COVERING THE W ATLC W OF 70W. A SURFACE RIDGE REMAINS OVER THE W ATLC S OF 30N W OF 67W AND N OF 30N W OF 55W WITH THE AXIS EXTENDING THROUGH 32N76W TO SAINT AUGUSTINE FLORIDA. A NARROW UPPER TROUGH IN THE CENTRAL ATLC EXTENDS FROM 29N61W THROUGH AN ILL-DEFINED UPPER LOW NEAR 24N65W INTO THE CENTRAL CARIBBEAN THROUGH THE MONA PASSAGE SUPPORTING A SURFACE TROUGH EXTENDING FROM 27N66W ALONG 24N66W TO 20N64W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-25N BETWEEN 62W-66W. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR COVERS THE REMAINDER OF THE W ATLC W OF 60W GIVING THE AREA FAIR WEATHER AGAIN THIS MORNING. A BROAD UPPER RIDGE IS TO THE E OF THE UPPER TROUGH ALONG 50W FROM 15N-30N. A SURFACE TROUGH IS EMBEDDED BENEATH THIS UPPER RIDGE ANALYZED FROM 27N51W 20N55W TO OVER SAINT LUCIA IN THE WINDWARD ISLANDS. THE UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 16N-23N BETWEEN 46W-58W AND ISOLATED SHOWERS FROM 20N-28N BETWEEN 42W-60W. A SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1033 MB HIGH OVER THE AZORES. SURFACE RIDGE N OF THE AREA WILL WEAKEN AND SHIFT SE THROUGH WED. A COLD FRONT WILL MOVE OFF THE SE CONUS COAST LATE WED THEN WILL EXTEND FROM W OF BERMUDA TO CENTRAL CUBA THU NIGHT WHERE IT WILL STALL AND WEAKEN TO A TROUGH THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW