000 AGXX40 KNHC 120720 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 320 AM EDT TUE JUN 12 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... WINDS AND SEAS AREA EXPECTED TO REMAIN BELOW ADVISORY CRITERIA UNTIL LATE FRI WHEN A BUILDING RIDGE OVER GA/AL WILL BUTT AGAINST TROUGHING OFF THE FL E COAST...INCREASING THE PRES GRADIENT OVER THE NE GULF. THERE IS NO REASON TO STRAY FROM A BLEND OF CONTINUITY AND THE 00Z GFS THROUGH THU. BY FRI...A BLEND OF THE 00Z GFS AND ECMWF WAS PREFERRED FOR THE PATTERN OVER THE SOUTHEASTERN U.S. AND ADJACENT WATERS. SEE THE SW N ATLC SECTION BELOW FOR DETAILS. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE 0130 UTC AND 0310 UTC ASCAT PASSES SHOW THE AREAL EXTENT OF THE FRESH TO STRONG WINDS IN THE CARIBBEAN HAS SHRANK SINCE THIS TIME YESTERDAY AS THE SUBTROPICAL HIGH OFF THE CAROLINA COAST HAS WEAKENED. RIDGING OVER THE CENTRAL ATLC WILL BE THE DOMINANT DRIVER OF THE TRADE WINDS THROUGH SAT. THE TROPICAL WAVE ALONG 69W WILL PASS THROUGH THE CENTRAL CARIBBEAN BY TONIGHT AND SLOW ITS WESTWARD PROGRESS STARTING WED AS THE BUILDING TROUGHING OVER FL AND THE BAHAMAS BEGINS TO DRAW THE WAVE ON A MORE NORTHWESTERLY TRACK. A BLEND OF THE GFS AND ECMWF IS PREFERRED WITH THIS TROUGHING AND THE GENERAL PATTERN N OF THE CARIBBEAN. SEE THE SECTION BELOW FOR DETAILS. THIS BUILDING TROUGHING WILL ENCROACH UPON THE RIDGING STEMMING FROM THE CENTRAL ATLC...DIMINISHING TRADES A NOTCH ON FRI AND SAT. THE TROPICAL WAVE WILL MAKE ITS WAY THROUGH THE WESTERN CARIBBEAN THU AND FRI. MOST OF THE MODELS TAKE IT INTO THE YUCATAN ON FRI...BUT THE NOGAPS DEVELOPS A CLOSED LOW PRES SYSTEM AND SENDS IT NORTHWARD TO THE YUCATAN CHANNEL ON SAT. THIS IS AN OUTLIER SOLUTION. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... THE SUBTROPICAL HIGH OVER THE WESTERN ATLC HAS BEEN COMPROMISED BY A DEEPENING...RETROGRADING SURFACE LOW AND ASSOCIATED COLD FRONT TO ITS E. THE MODELS ARE IN REASONABLE AGREEMENT ON THIS SCENARIO. THEY DIFFER WITH THE EVOLUTION OF THE COLD FRONT EXPECTED TO PASS OF THE MID ATLC COAST WED...WITH THE ECMWF DEEPER AND GENERALLY MORE EASTERLY WITH THE PRIMARY SURFACE LOW BY THU THAN THE GFS. THE CMC IS EVEN DEEPER AND MORE EASTERLY THAN THE ECMWF WHILE THE NOGAPS IS CONSIDERABLY WEAKER THAN THE OTHER MODELS. THE UKMET LOOKS LIKE A COMPROMISE BETWEEN THE GFS AND ECMWF...HOLDING A 1011 MB LOW PRES SYSTEM NEAR 30N70W SAT MORNING. THE GEFS MEAN IS ALSO IN AGREEMENT WITH THIS LOW POSITION AND STRENGTH AT THAT TIME...WITH THE ECMWF ENSEMBLE MEAN SHOWING A MORE WASHED OUT...WEAKER PATTERN. HOWEVER...THE MODELS ALSO SHOW THE DEVELOPMENT OF A WAVE ALONG THIS BOUNDARY TRAILING THIS LOW. THIS WAVE IS EXPECTED TO MOVE OFF THE SC COAST WED AND LIE N OF THE BAHAMAS FRI EVENING. THE UKMET IS DEEPER AND MORE WESTERLY THAN THE GFS AND ECMWF WITH THIS LOW. CONFIDENCE IS LOW IN ITS SOLUTION HERE. THERE IS STILL CONSIDERABLE UNCERTAINTY WITH THIS PATTERN...SO ADJUSTMENTS WILL BE MADE TOWARD A ECMWF/GFS BLEND OVER THE SW N ATLC. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE) GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER