000 AGXX40 KNHC 221917 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 220 PM EST THU NOV 22 2012 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... HIGH PRES OVER SE STATES MOVES INTO N GULF COASTAL WATERS WITH ANTICYCLONIC GENTLE TO MODERATE BREEZE N OF 25N THROUGH LATE FRI NIGHT. WEAK SURFACE TROUGH IN EXTREME SW BAY OF CAMPECHE INCREASES WINDS S OF 25N TO A FRESH BREEZE IN ITS VICINITY. WEAK COLD FRONT ENTERS NORTHERN ZONES REACHING FROM FLORIDA BIG BEND TO SE TEXAS EARLY SAT WITH FRESH NE BREEZE THROUGH LATE SAT THEN VEER E AND WEAKEN. SEAS SURGE TO 5-6 FT N OF COLD FRONT BUT LAY DOWN AGAIN BY EARLY SUN. BROAD 1024 MB HIGH PRES BUILDS OVER SE STATES AND RETURNS NE-NE FLOW BACK TO N HALF OF GULF WHILE LIGHT TO GENTLE BREEZE TAKE OVER S OF 25N THROUGH MON. FORECAST FOLLOWS GFS GUIDANCE WHICH HAS HAD A GOOD HANDLE ON SCENE THROUGH LAST RUNS. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... LOW LEVEL CONVERGENCE OVER SW CARIBBEAN CONTINUES WITH FRESH N BREEZE MIXING WITH MODERATE EASTERLY TRADES S OF 12N BUT CONVECTION SUBSIDED SINCE PRIOR UPPER LEVEL DIVERGENCE LEFT THE SCENE AND SURFACE 1012 MB LOW PRES SW OF COSTA RICA WEAKENED. UPPER LEVEL TROUGH OVER SW N ATLC SWEEPS SE BRINGING DRY AIR MASS PRESENTLY N OF 15N W OF 80W. CREST OF UPPER LEVEL RIDGE NOW ANCHORED OVER SOUTHERN VENEZUELA FLATTENS AS TROUGH BRINGS 40-50 KT JET ACROSS NORTH HALF OF CARIBBEAN. MODERATE E BREEZE OVER EASTERN CARIBBEAN INCREASE LATE IN FORECAST PERIOD AS CENTRAL ATLC HIGH PRES IS REINFORCED AFTER PASSAGE OF COLD FRONT ASSOCIATED WITH AFOREMENTIONED UPPER LEVEL TROUGH. EXCEPT FOR WESTERN CARIBBEAN S OF 15N WHERE FRESH N WINDS HAVE BUILT SEAS TO 6-7 FT...REMAINDER CARIBBEAN CONTINUES WITH SEAS 4 FT OR LESS. THIS CHANGES BY END OF PERIOD WHEN INCREASE IN EASTERLIES BUILD SEAS TO 7 FT. SW N ATLC W OF 55W... COLD FRONT EXTEND FROM STRONG 1004 MB LOW PRES CENTER JUST N OF AREA AT 33N68W TO 31N68W TO 21N73W. STRONG TO NEAR GALE NW TO N WINDS W OF FRONT BUILDING SEAS TO 12-14 FT E OF BAHAMAS AND 6-8 W OF BAHAMA BANK. LATEST MODEL GUIDANCE SOLUTIONS HAVE BACKED FROM GALE FORCE...NEVERTHELESS WITH COLD AIR ADVECTION RUNNING OVER WARM GULFSTREAM CURRENT...SHORT PERIODS OF GALE FORCE WIND GUSTS MAY BE RECORDED. DEEP LAYER CYCLONE SUPPORTING FRONT SHIFTS NE THUS WEAKENING BOUNDARY AND DIMINISHING WINDS. SEAS ARE SLOW TO SUBSIDE AS WEAKER FRONT BRING SECOND SURGE OF N WINDS...NOT AS STRONG...MAINTAINING SEAS NEAR 8-10 FT IN N SWELLS THROUGH LATE SUN...THEN DROPPING BELOW 8 FT BY MON. HIGH PRES BUILDS OVER BASIN MON WITH GENTLE TO MODERATE E WINDS BY MON AND BEYOND. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER WALLY BARNES