000 AGXX40 KNHC 131800 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 100 PM EST TUE NOV 13 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... A COLD FRONT EXTENDS FROM THE FLORIDA BIG BEND AREA TO 23N94W...THEN SOUTH TO 18.5N95W. BUOY AND SHIP OBSERVATIONS OVER THE N CENTRAL AND NW GULF INDICATE FRESH TO STRONG N TO NE WINDS BEHIND THE FRONT. SEAS HAD BEEN AS HIGH AS 13 FT AT BUOY 42003 POSITIONED NEAR 25.7N93.9W. THE SEAS ARE GRADUALLY SUBSIDING WITH HIGHEST SEAS AROUND 9 TO 10 FT. THE UPPER TROUGH SUPPORTING THE COLD FRONT IS MOVING E THROUGH 85W CURRENTLY. THE COLD FRONT WILL STALL AND DISSIPATE THROUGH TODAY AS THE UPPER TROUGH LIFTS NE OF THE AREA...ALLOWING FRESH TO STRONG WINDS OVER THE NW GULF TO GRADUALLY DIMINISH THROUGH WED. GLOBAL MODELS INDICATE A WEAK SHORT WAVE TROUGH WILL MIGRATE ACROSS THE GULF THROUGH THE LOWER MISSISSIPPI VALLEY AND NE GULF WED AND THU WITH LITTLE IMPACT ON THE SENSIBLE WEATHER. LOOKING AHEAD...GLOBAL MODELS ARE IN CLOSE AGREEMENT SHOWING AN NEGATIVELY TILTED MID TO UPPER TROUGH PUSHING INTO THE SE UNITED STATES BY FRI. THE ECMWF IS TRENDING IN BETTER AGREEMENT WITH THE UKMET INDICATING A CUT OFF LOW FORMING OVER GEORGIA BY SAT...WITH THE GFS REMAINING SOMEWHAT WEAKER. THE OVERALL PATTERNS HINTS OF A MILD REINFORCING FRONT MOVING THROUGH GULF WATERS FRI INTO SAT WITH LITTLE CHANGE IN WINDS OR SEAS. CARIBBEAN AND TROPICAL ATLC W OF 55W... BUOY AND SCATTEROMETER DATA SHOW GENERALLY MODERATE TO FRESH NE TO E WINDS FROM THE LEEWARD ISLANDS THROUGH THE WESTERN CARIBBEAN. SHIP OBSERVATIONS INDICATE OCCASIONAL WINDS TO 20 KT OVER THE GULF OF HONDURAS. AN EARLIER ASCAT PASS FROM AROUND 02 UTC INDICATED WINDS TO 20 KT FUNNELING THROUGH THE WINDWARD PASSAGE AHEAD OF A SURFACE TROUGH N OF HISPANIOLA ALONG 68W. ALTHOUGH WINDS MAY HAVE BEEN ENHANCED AHEAD OF THE TROUGH THROUGH THE WINDWARD PASSAGE...THE TROUGH IS BREAKING UP THE NORMAL PRES GRADIENT IN PLACE N OF THE CARIBBEAN...ALLOWING SLIGHTLY DIMINISHED TRADE WIND FLOW TO PREVAIL. BUOYS E OF THE ISLANDS IN THE TROPICAL ATLC ARE SHOWING SEAS OF 8 TO 9 FT IN N AND NE SWELL. BOTH THE WW3 AND ECWAVE INDICATE THIS SWELL WILL DECAY BELOW 8 FT THROUGH TONIGHT. NO MAJOR CHANGES ARE ANTICIPATED THROUGH FRI IN THE OVERALL PATTERN OR FORECAST. A WEAKENING COLD FRONT WILL LIKELY MOVE INTO THE NW CARIBBEAN BY LATE SAT. SOUTHWEST NORTH ATLC S OF 31N W OF 65W... A SHARPLY AMPLIFIED SURFACE TROUGH ASSOCIATED WITH AN UPPER CYCLONE EXTENDS FROM 31N62W TO 21N68W. CLUSTERS OF SHOWERS AND THUNDERSTORMS ARE NOTED NEAR THE CENTER OF THE UPPER CYCLONE...NEAR 27N67W. A TIGHT PRES GRADIENT BETWEEN THE TROUGH AND RIDGING TO THE NORTH IS SUPPORTING FRESH NE FLOW. BUOY 41047 NEAR 27.5N72W HAS BEEN SHOWING WINDS 20 TO 25 KT...ALTHOUGH THIS IS STARTING TO DIMINISH. A RECENT ASCAT PASS FROM 14 UTC SHOWED GENERALLY 15 TO 20 KT BETWEEN 70W AND 75W. THE PERSISTENT LONG FETCH OF FRESH TO STRONG NE FLOW HAS ALLOWED A BROAD AREA OF SEAS TO BUILD REACHING 8 TO 12 FT OUTSIDE OF THE BAHAMAS. WAVE GUIDANCE FROM WW3...ECWAVE AND THEIR RESPECTIVE ENSEMBLE RUNS INDICATE THE SEAS WILL BE GRADUALLY DIMINISHING BELOW 8 FT THROUGH MIDDAY WED. WINDS AND SEAS SUBSIDE WED THROUGH FRI AS THE TROUGH DEAMPLIFIED AND THE PRES GRADIENT WEAKENS. LOOKING AHEAD TO THE WEEKEND...GLOBAL MODELS ARE IN CLOSE AGREEMENT SHOWING AN NEGATIVELY TILTED MID TO UPPER TROUGH PUSHING INTO THE SE UNITED STATES BY FRI. THE ECMWF IS TRENDING IN BETTER AGREEMENT WITH THE UKMET INDICATING A CUT OFF LOW FORMING OVER GEORGIA BY SAT...WITH THE GFS REMAINING SOMEWHAT WEAKER. THE UKMET FORMS A SURFACE LOW OFF NE FLORIDA FRI INTO SAT. FORECAST FOLLOWS MORE CONSERVATIVE GFS SOLUTION FOR NOW BUT GIVEN THE SLIGHT NEGATIVE TILT TO THE SUPPORTING UPPER TROUGH THIS MAY BE ADJUSTED IN TIME. AT ANY RATE...ALL SOLUTIONS SHOW ONLY MODERATE WINDS FRI AND SAT. 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 CHRISTENSEN