000 AGXX40 KNHC 100602 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 130 AM EST SAT DEC 10 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... NEW HIGH PRES IS BUILDING NW OF THE GULF BEHIND A DISSIPATING COLD FRONT OVER THE LOWER MISSISSIPPI VALLEY. MODERATE TO FRESH NE-E WINDS ARE ACROSS THE GULF AS INDICATED BY RECENT WINDSAT AND ASCAT SCATTEROMETER PASSES...WITH 15-25 KT IN THE N GULF AND 10-15 KT IN THE S GULF. MEANWHILE...A TROUGH WILL DEVELOP AND THEN LINGER NEAR THE COAST OVER THE TEXAS/MEXICO BORDER REGION. HIGH PRES WILL CONTINUE TO BUILD N OF THE AREA THROUGH EARLY SUN WITH THE AREA OF 20-25 KT WINDS EXPANDING TO ACROSS THE WATERS N OF 21N...AND SEAS WILL BUILD TO UP TO 11 FT IN THE W CENTRAL GULF WITH A LENGTHENING NE-E FETCH. THE HIGH WILL THEN WEAKEN SUN NIGHT THROUGH TUE WHILE THE TROUGH DISSIPATES ALLOWING FOR WINDS AND SEAS TO GRADUALLY DIMINISH AND SUBSIDE EARLY NEXT WEEK. SOUTHERLY RETURN FLOW WILL BECOME ESTABLISHED IN THE W GULF WED AS THE NEXT COLD FRONT MOVES INTO CENTRAL TEXAS. CARIBBEAN SEA AND TROPICAL N ATLC... A SHEAR LINE IS IN THE NW CARIBBEAN REACHING FROM CENTRAL CUBA TO THE EASTERN GULF OF HONDURAS. SURFACE OBSERVATIONS W OF THE SHEAR LINE INDICATE NORTHERLY 20 KT WINDS WHILE AN EARLIER JASON ALTIMETER PASS SHOWED SEAS TO 6 FT. N-NE WINDS ARE 5-10 KT JUST E-SE OF THIS FEATURE. MEANWHILE A RECENT ASCAT PASS CAPTURED NE-E 15-20 KT WINDS IN THE CENTRAL CARIBBEAN WITH LIGHT AND VARIABLE WINDS IN THE E CARIBBEAN. THE SHEAR LINE WILL BECOME LESS DEFINED WHILE SAGGING TO THE SE THROUGH THE NEXT 48 HOURS. A BROAD AND WEAK PRES PATTERN WILL DOMINATE OVER THE CARIBBEAN WATERS THROUGH SUN WITH MAINLY MODERATE TRADE WINDS ACROSS THE BASIN...EXCEPT TO 20 KT ALONG THE EASTERN NICARAGUA COAST AS WELL AS NEAR THE YUCATAN CHANNEL...WINDWARD PASSAGE AND IN THE LEE OF CUBA AND HISPANIOLA. THE PRES GRADIENT WILL THEN TIGHTEN OVER THE NW CARIBBEAN EARLY NEXT WEEK AS HIGH PRES BUILDS OVER THE U.S. MID-ATLANTIC STATES...RESULTING IN FRESH NE WINDS WITH SEAS BUILDING TO 8 FT BY THE END OF THE FORECAST PERIOD. MEANWHILE...ANOTHER SHEAR LINE IS DRAPED ACROSS THE CENTRAL TROPICAL N ATLC WATERS NEAR 17N55W WESTWARD TO PUERTO RICO...AS INDICATED BY A 0156 UTC ASCAT PASS WHICH SHOWED NE-E 20-25 KT WINDS N OF THIS FEATURE AND ONLY 5-10 KT TO THE S OF IT. LOW-LEVEL MOISTURE CONTINUES TO FEED UP FROM THE DEEP TROPICS OVER THE E CARIBBEAN TO ACROSS THE LESSER ANTILLES RESULTING IN CONTINUED RAINFALL AND THE LINGERING CHANCES OF FLASH FLOODING AND MUDSLIDES...WITH THE SHEAR LINE HELPING TO ENHANCE THE CONVECTION OVER THE ISLANDS. BUOY OBSERVATIONS IN THE NORTHERN TROPICAL N ATLC INDICATE 8-10 FT SEAS IN NE-E SWELL. THE SHEAR LINE WILL BECOME DIFFUSE LATER TODAY...DISSIPATING TONIGHT AS A TROUGH ENTERS THE REGION FROM THE E. THIS TROUGH WILL THEN LIFT NW OF THE AREA SUN NIGHT WITH THE HIGHEST ASSOCIATED WINDS EXPECTED TO REMAIN JUST OUTSIDE OF THE OFFSHORE WATERS. HOWEVER EASTERLY SWELL OF 8-10 FT WILL PERSIST N OF 17N THROUGH TUE... SUBSIDING WED. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... A FRONTAL TROUGH IS IN THE W PORTION AS SHOWN BY A 0200 UTC ASCAT PASS EXTENDING FROM 31N72W TO ACROSS THE WESTERN BAHAMAS. WINDS ARE 10-15 KT NW OF THE TROUGH...WHILE 15-20 KT NE-E WINDS WERE NOTED BY THE ASCAT PASS AS WELL AS BY MULTIPLE SHIPS AND BUOYS IN THE SE PORTION OF THE OFFSHORE ZONE. THIS TROUGH WILL BECOME DIFFUSE TODAY EVENTUALLY MERGING WITH A NEW COLD FRONT WHICH WILL MOVE SE OFF OF THE GEORGIA/N FLORIDA COASTS TONIGHT. EXPECT FRESH TO STRONG NE WINDS BEHIND THIS FRONT WITH SEAS BUILDING TO 13-14 FT OFF THE NE FLORIDA COAST AT THE TAIL END OF A HEALTHY NE FETCH ZONE. THE NEW FRONT WILL THEN STALL OUT E OF FLORIDA SUN AFTERNOON...WITH ANOTHER REINFORCING SURGE OF NE WINDS IMPACTING THE NW PORTION EARLY NEXT WEEK. MEANWHILE...THE AFOREMENTIONED TROUGH IN THE TROPICAL N ATLC WILL DRIFT INTO THE E PORTION OF THE AREA LATE SUN NIGHT INTO MON WITH SEAS BUILDING TO 10 FT IN E-SE SWELL BEHIND IT. THIS TROUGH WILL MERGE WITH THE LATEST REINFORCING FRONT LATE MON...AND THE FEATURES WILL FINALLY SHIFT E OF THE AREA BY LATE TUE AS HIGH PRES BUILDS IN FROM THE NW. THE HIGH WILL SHIFT TO THE SE AND WILL BECOME ALIGNED ALONG 31N BY LATE WED ALLOWING FOR WINDS AND SEAS TO RELAX N OF 27N. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER LEWITSKY/SCHAUER