000 AGXX40 KNHC 040718 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 220 AM EST TUE DEC 04 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... WEAKENING HIGH PRES OFFSHORE OF THE CAROLINAS WILL CONTINUE TO DRIVE THE WINDS OVER THE GULF TODAY. SHIP PHFV REPORTED 24 KT IN THE STRAITS OF FLORIDA AT 0400 UTC AND SEVERAL OTHER OBSERVATIONS IN THE SE GULF OVER THE PAST FEW HOURS HAVE REPORTED FRESH E WINDS. THE 00Z GFS SEEMS TO BE DOING A GOOD JOB HERE WITH THE WINDS. WILL BUMP UP SEAS FOR TODAY WHILE THE WINDS REMAIN FRESH TO STRONG AS THE WWW3 HAS CONSISTENTLY BEEN TO LOW WITH THE SEAS IN THE REGION UNDER THIS FRESH TO STRONG EASTERLY FLOW REGIME...ESPECIALLY AGAINST THE CURRENT IN THE STRAITS OF FLORIDA. BOTH THE 00Z GFS AND ECMWF HAVE TRENDED SLIGHTLY FASTER MOVING A WEAK COLD FRONT INTO THE NW GULF TUE NIGHT. IT IS EXPECTED TO MOVE OFFSHORE WITH LITTLE FANFARE ASIDE FROM SHOWERS AND THUNDERSTORMS. THE 00Z GFS AND ECMWF CARRY THE BOUNDARY INTO THE CENTRAL GULF BEFORE RETROGRADING IT NORTH AND DISSIPATING IT BY THU...BUT WINDS AND SEAS WILL STILL REMAIN WELL BELOW ADVISORY CRITERIA. BY FRI...DEEP-LAYER TROUGHING BUILDING IN THE U.S. PLAINS STATES WILL ENHANCE RETURN FLOW OVER THE WESTERN GULF WITH SOUTHERLY WINDS BECOMING FRESH THROUGH SAT. BEYOND TODAY...A BLEND OF THE GFS AND ECMWF SOLUTIONS WILL BE USED TO UPDATE THE GRIDS. CARIBBEAN SEA AND TROPICAL N ATLC S OF 19N W OF 55W... WEAKENING HIGH PRES OFF THE CAROLINA COAST CONTINUES TO DRIVE THE NE FLOW THROUGH THE CARIBBEAN. FRESH TO STRONG WINDS HAVE PENETRATED THE NW CARIBBEAN...THE WINDWARD PASSAGE...AND THE LEE OF THE DOMINICAN REPUBLIC ACCORDING TO THE 0250 UTC ASCAT AND 2216 UTC WINDSAT PASSES. BOTH THE 00Z GFS AND ECMWF APPEAR WELL INITIALIZED WITH THESE FRESH TO STRONG WINDS. WILL BUMP THE SEAS UP IN THE WINDWARD PASSAGE SLIGHTLY COMPARED TO THE WW3...AS HAS BEEN THE CASE THE LAST FEW NIGHTS...TO BE MORE COMMISERATE WITH THE STRONG WINDS FUNNELING THROUGH THE REGION. WINDS DIMINISH WED AND THU AND LOCALLY FRESH TRADES PICK UP FRI AND SAT IN THE TROPICAL N ATLC...N CENTRAL CARIBBEAN AND NE CARIBBEAN AS NEW HIGH PRES BUILDS TO THE N. SW N ATLC N OF 19N W OF 55W... FRESH TO STRONG NE WINDS HAVE SHIFTED S OF 26N AS THE PRES GRADIENT IN PLACE BETWEEN TROUGHING OVER THE EASTERN CARIBBEAN AND WEAKENING HIGH PRES OFF THE CAROLINA COAST HAS SLACKENED. THE 00Z GFS AND ECMWF APPEAR TO BE DOING REASONABLY WELL WITH THE WIND FIELD. THEIR CORRESPONDING WAVE MODELS ALSO APPEAR TO BE PERFORMING WELL COMPARED TO BUOY OBSERVATIONS. WINDS AND SEAS SHOULD GRADUALLY DIMINISH HERE THROUGH WED. FARTHER E...CONFIDENCE CONTINUES TO BE LOW IN THE FORECAST FOR THE REGION E OF 70W AS THE LINGERING MID LEVEL ENERGY ASSOCIATED WITH THE DISSOLVED SHEAR LINE INTERACTS WITH AN AMPLIFYING...POSITIVELY TILTED MID-LEVEL TROUGH AND ITS ASSOCIATED ENERGY. BOTH THE GFS AND ECMWF ARE WELL INITIALIZED WITH THE 1011 MB LOW PRES SYSTEM NEAR 21N58W AT 0000 UTC...BUT THEY DIVERGE QUICKLY IN THE FORECAST PERIOD WITH THE STRENGTH OF THIS SYSTEM AS IT MOVES NORTHEASTWARD. BOTH MODELS FORECAST MULTIPLE WAVES ALONG A BOUNDARY THAT EXTENDS TO THE ARE THIS LOW SYSTEM IS CURRENTLY FOUND NORTHEASTWARD. THE ECMWF AND UKMET ARE MORE EMPHATIC ABOUT TWO DISTINCT LOW PRES CENTERS HERE COMPARED TO GFS. THE ECMWF IS STRONGER THAN THE GFS SOLUTION....DEEPENING THE LOW TO 1000 MB WELL E OF THE AREA NEAR 31N42W BY FHR 48 WHILE THE GFS IS ONLY 1005 MB. THE 00Z CMC AND UKMET MODELS AGREE WITH THE ECMWF STRENGTH. BOTH THE GFS AND ECMWF BRING WINDS TO NEAR GALE FORCE OVERNIGHT TONIGHT...BUT DIFFER SIGNIFICANTLY ON THE LOCATION. THE FORECAST UPDATE WILL RELY MORE HEAVILY ON THE ECMWF WHICH APPEAR TO HAVE MORE SUPPORT FROM THE OTHER MODELS. ELSEWHERE...A NEW COLD FRONT WILL MOVE INTO NW WATERS BY THU NIGHT. THE 00Z GFS HAS TRENDED TOWARD THE WEAKER ECMWF WITH THE FRONT AS WELL AS WITH THE INVERTED TROUGH THROUGH THE BAHAMAS AND IS EXPECTED TO KEEP THE FRONT FARTHER N. THE 00Z GFS HAS TRENDED TOWARD THE ECMWF AND UKMET WITH A STRONGER...SLOWER THE DEEP LAYER TROUGH PASSING THROUGH THE GULF OF MEXICO WED AND REACHING THE SW N ATLC THU AND FRI BEFORE WEAKENING AND PASSING E SAT. A BLEND OF THE ECMWF AND GFS SEEMS REASONABLE HERE AS WELL. 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