000 AGXX40 KNHC 291755 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 100 PM EST TUE DEC 29 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... A TROUGH ALONG THE E COAST OF TEXAS AND NE OLD MEXICO WILL PERSIST WITH LOW PRES DEVELOPING ALONG THE TROUGH OVER NE TEXAS LATE TONIGHT. THE LOW WILL MOVE GENERALLY NE TO NEAR OR JUST N OF THE MS DELTA WED NIGHT DRAGGING THE TROUGH BACK OVER THE WESTERN GULF. A NLY SURGE OF COLD AIR WILL SWEEP SE INTO THE NW GULF LATE THU INTO THU NIGHT...NOTE ABOUT 12 HOURS LATER THAN PREVIOUSLY EXPECTED...AND MERGE WITH THE TROUGH. WILL REFER TO TROUGH AS DEVELOPING COLD FRONT FOR SIMPLICITY IN ALPHANUMERICS. EXPECTING THIS MERGED BOUNDARY TO REACH LINE FROM TAMPA BAY TO BAY OF CAMPECHE SUNRISE FRI THEN MOVE THROUGH YUCATAN CHANNEL AND FL STRAITS AROUND SUNSET FRI. ENTIRE GULF EXPERIENCING 20-25 KT NLY WINDS BY LATE FRI WITH WINDS BECOMING SLY OVER NW WATERS SAT NIGHT AND DIMINISHING TO NE AT 10 TO 15 KT ELSEWHERE. NEXT COLD FRONT OFF TX COAST SUN NIGHT AND COULD BE A GALE EVENT. CARIBBEAN AND TROPICAL N ATLC W OF 55W... HIGH PRES WILL BUILD N OF AREA TONIGHT TIGHTENING THE PRES GRADIENT AND INCREASING NE TRADES TO 15-20 KT WITH THESE CONDITIONS SPREADING FROM W TO E THROUGH THU. THE GRADIENT WEAKENS OVER THE NW CARIBBEAN THU INTO FRI. LONG PERIOD N SWELL WILL CONTINUE ACROSS THE ATLC WATERS E OF THE ANTILLES AND ALSO SEEP THROUGH THE EXPOSED ATLC PASSAGES THROUGH TUE...THEN GRADUALLY DECAYING WED THROUGH THU AS ANOTHER FRONT ACCOMPANIED BY LARGE SWELLS MOVES INTO THE NORTHERN TROPICAL ZONE WITH PATTERN REPEATING SUN NIGHT INTO MON. ENHANCED WINDS AND SEAS ALONG COAST OF COLOMBIA WILL DIMINISH SOME FRI THROUGH SUN. SW N ATLC S OF 31N W OF 55W... A COUPLE OF COLDS FRONT MERGING OVER THE SW ATLC WATERS WAS SIMPLIFIED TO ONE FRONT IN THIS MORNING TEXT FORECASTS AND SOMEWHAT SIMPLIFIED ON THE UNIFIED SURFACE ANALYSIS AS WELL. EXPECT THIS MERGED FRONT TO MOVE E OF 65W EARLY TONIGHT. POST FRONTAL NLY FLOW AT 20 TO 25 KT WILL DIMINISH AND BECOME SLY OVER THE NW WATERS EARLY WED NIGHT. A COASTAL TROUGH WILL SET UP IN THE RETURN FLOW WED NIGHT ALONG FL AND GA COASTS AND FURTHER N WHERE LOW PRES IS EXPECTED TO DEVELOP ALONG THIS TROUGH. AS THE LOW MOVES NE IT WILL DRAG ANOTHER COLD FRONT INTO THE NW WATERS LATE THU NIGHT WITH THE FRONT REACHING THE SE WATERS SUNRISE SUN. EXPECT SLY AND WLY FLOW TO REACH MINIMAL GALE N OF 29N ALONG FRONT FRI JUST AFTER SUNNRISE WITH THE SUPPORTING ENERGY LIFTING OF AREA EARLY FRI NIGHT. ANOTHER BOUT OF LARGE N SWELLS WILL PROPAGATE S THROUGH WATERS E OF THE BAHAMIAN CHAIN SAT AND SUN. WARNINGS... ATLC... .NONE. AMZ080...GALE CONDITIONS EXPECTED FRI N OF 29N ALONG FRONT. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON