000 AGXX40 KNHC 010707 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 210 AM EST FRI DEC 01 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... STRONG HIGH PRES JUST OFFSHORE OF THE CAROLINAS WILL DRIVE THE WINDS OVER THE GULF THROUGH TUE. A COLD FRONT WILL WEAKEN THIS HIGH PRES AND PUSH IT EASTWARD TUE INTO WED...WITH THE WEAKENED FRONT EXPECTED TO MOVE INTO THE NW GULF BY EARLY WED WITH LITTLE FANFARE ASIDE FROM SHOWERS AND THUNDERSTORMS. MODERATE ANTICYCLONIC FLOW WILL DOMINATE MUCH OF THE REGION WITH THE EXCEPTION OF THE SE GULF. WITH THE 0214 UTC ASCAT AND 2312 UTC WINDSAT PASSES SHOWING E WINDS TO 25 KT IN THE SE GULF AND STRAITS OF FLORIDA...WILL NEED TO BUMP UP THE GRIDS ABOUT 5 KT IN THIS AREA INITIALLY. THIS INCREASE SHOULD EXTEND INTO THE FORECAST PERIOD AS THE SYNOPTIC PATTERN SHOULD REMAIN RELATIVELY UNCHANGED OVER THE NEXT FEW DAYS. THE WW3 TYPICALLY DOES NOT CAPTURE PEAK AREA OF SEAS THROUGH THE STRAITS AND ACROSS YUCATAN CHANNEL. GRIDS WILL GO ABOVE GUIDANCE IN THE UPDATED FORECAST...WITH SEAS LIKELY TO LINGER AROUND 6-8 FT THROUGH TUE...AND LIKELY EVEN HIGHER AGAINST CURRENT. THE 2334 UTC JASON1 PASS SHOWED SEAS TO 9 FT NEAR 25N86.5W. THIS IS APPROXIMATELY 3 FT HIGHER THAN THE 00Z WW3 AND 4 FT HIGHER THAN THE 00Z EC WAVE. THE 00Z GFS AND ECMWF ARE IN GOOD AGREEMENT ON THE PATTERN HERE...INCLUDING THE FRONTAL TIMING ON WED. A BLEND OF THEIR SOLUTIONS WILL BE USED TO UPDATE THE GRIDS. CARIBBEAN SEA AND TROPICAL N ATLC S OF 19N W OF 55W... STRONG HIGH PRES JUST OFF THE CAROLINA COAST IS DRIVING THE EASTERLY FLOW THROUGH THIS REGION. A SHEAR LINE N OF THE AREA IS FORCING GRADIENT WINDS TO REMAIN N OF THE BASIN...AND WILL ONLY ALLOW FOR FRESH WINDS TO PENETRATE N PORTIONS OF THE CARIBBEAN AS WELL AS THE WINDWARD PASSAGE. OTHERWISE...MODERATE TO LIGHT NE TRADES WILL PREVAIL ACROSS THE REGION THROUGH TUE. THE ECMWF AND GFS AGREE ON INCREASING NE WINDS TO FRESH TO STRONG IN THE WINDWARD PASSAGE ON SUN AS THE SHEAR LINE TO THE N UNDULATES DUE TO THE HIGH PRES OFF THE CAROLINAS MIGRATING SOUTHWARD. THE GLOBAL MODELS SEEM TO HAVE A HARD TIME RESOLVING THE FUNNELING THROUGH THE WINDWARD PASSAGE. THEY ARE FREQUENTLY TOO LOW WITH THE WIND SPEED HERE UNDER A BROADLY FRESH TO STRONG NE FLOW REGIME. THEREFORE...BUMPED THE WINDS UP 5 KT COMPARED TO THE MODELS SUN THROUGH TUE AND ADJUSTED SEAS ACCORDINGLY. ELSEWHERE...MODERATE TO LOCALLY FRESH NE TRADE WINDS IN THE TROPICAL N ATLC ZONE WILL PREVAIL THROUGH THE FORECAST PERIOD...WITH BOTH WINDS AND SEAS REMAINING BELOW ADVISORY CRITERIA. A BLEND OF THE 00Z GFS AND ECMWF WAS USED TO ADJUST THE FORECAST. SW N ATLC N OF 19N W OF 55W... A SHEAR LINE LIES FROM 28N55W THROUGH 24N70W TO 20N74W AS OF 00Z...WITH FRESH TO STRONG E-NE WINDS TO THE N AND MODERATE E-NE WINDS TO THE S OF THE SHEAR LINE. BUOYS SHOW SEAS ARE A SOLID 9-10 FT E OF BAHAMAS AND N OF THE SHEAR LINE. THE 00Z WW3 AND EC WAVE ARE RUNNING ABOUT A FOOT LOW. THE SHEAR LINE IS EXPECTED TO MOVE S OVER THE NEXT FEW DAYS AS THE HIGH PRES JUST OFF THE NORTH CAROLINA COAST AT PRESENT DIPS SOUTHWARD SUN-TUE BEFORE WEAKENING. E OF THE FORECAST AREA...A FAIRLY WELL-DEFINED SURFACE CIRCULATION HAS DEVELOPED WITH THE LOW PRES SYSTEM NEAR 25N43W. THE 0032 UTC ASCAT PASS SHOWS WINDS TO 25 KT ON THE E SIDE OF THE LOW. BOTH THE 00Z GFS OR ECMWF ARE 5 KT TOO WEAK WITH THE WINDS HERE...SO WINDS WILL BE BUMPED UP INITIALLY AND EARLY IN THE FORECAST PERIOD. THIS SYSTEM IS BEING DRAWN NORTHWARD TOWARD THE LEADING EDGE OF THE AFOREMENTIONED SHEAR LINE. IT HAS THE POTENTIAL TO BRIEFLY BECOME A TROPICAL CYCLONE BEFORE MOVING N OF THE FORECAST AREA SUN. THE 00Z GFS DEEPENS THIS LOW SLIGHTLY FASTER THAN THE OTHER MODELS WHICH HAVE BEEN TRENDING TOWARD THE CONSISTENTLY DEEPER GFS SOLUTION. WILL LEAN TOWARD THE GFS HERE. THE 00Z GEFS MEMBERS SHOW...AT BEST...A 10 PERCENT CHANCE OF GALE CONDITIONS DEVELOPING IN THE HSFAT2 WATERS...WAITING UNTIL THE SYSTEM IS N OF 31N TO DEEPEN ENOUGH FOR GALES/TROPICAL STORM FORCE WINDS. LIKEWISE...THE GEFS SHOWS A 10 PERCENT CHANCE AT BEST FOR GALES DEVELOPING THROUGH WED WITH THE NEXT POSSIBLE LOW PRES SYSTEMS EXPECTED MANIFEST THEMSELVES AS SURFACE WAVES ALONG THE SHEAR LINE OVER SE WATERS MON AND LIFT NE AWAY FROM THE AREA THROUGH WED. THE 00Z ECMWF AND GFS AGREE ON THE DEVELOPMENT OF A POSITIVELY-TILTED DEEP-LAYERED TROUGH SETTING UP FROM 31N50W TO HISPANIOLA DURING THIS TIME AND CARRY ANY SURFACE WAVES QUICKLY NORTHEASTWARD ALONG THE BOUNDARY AND E OF THE FORECAST AREA. CONFIDENCE IS LOW IN THE DETAILS WITH THESE SURFACE WAVES. A BLEND OF THE 00Z GFS AND ECMWF WILL BE USED TO ACCOUNT FOR THE UNCERTAINTY IN THE FORECAST HERE. 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 SCHAUER