000 AGXX40 KNHC 080722 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 225 AM EST TUE JAN 08 2013 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... OBSERVATIONS SHOW THAT WINDS AND SEAS HAVE DIMINISHED BELOW ADVISORY CRITERIA ACROSS THE GULF. CONDITIONS SHOULD REMAIN AS SUCH UNTIL A CUT OFF LOW MOVING THROUGH THE SOUTHWESTERN U.S. TODAY SHIFTS THE WINDS SOUTHEASTERLY OVER THE WESTERN GULF...WITH WINDS EXPECTED TO REACH 25 KT AHEAD OF THE ASSOCIATED COLD FRONT OVERNIGHT TONIGHT. THE 0000 UTC GFS AND ECMWF ARE IN REASONABLE AGREEMENT WITH THE EVOLUTION OF THIS SYSTEM UNTIL THU WHEN THE GFS BECOMES A FAST OUTLIER AMONG THE GLOBAL GUIDANCE. HOWEVER...THE GFS IS IN BETTER AGREEMENT WITH THE FASTER 0000 UTC GEFS AND 7/1200 UTC ECMWF ENSEMBLE MEANS. CONFIDENCE IS LOW IN THE DETAILS...SO A BLEND OF THE 0000 UTC GFS AND ECMWF WILL BE USED TO UPDATE THE FORECAST FOR THIS FEATURE. BY LATE FRI...A NEW TROUGH APPROACHING FROM THE W WILL ONCE AGAIN INCREASE THE SOUTHERLY RETURN FLOW IN THE WESTERN GULF. WHILE THE GFS IS ON THE SLOW END OF THE GUIDANCE THE UPPER TROUGH BY THE WEEKEND...THE ECMWF AND GFS AGREE REASONABLY WELL ON THE WINDS AND SEAS IN THE GULF AND THE TIMING OF THE COLD FRONT WHICH MAKES IT WAY OFFSHORE AROUND 0600 UTC SUN. WILL CONTINUE TO USE A GFS/ECMWF BLEND HERE LATE IN THE PERIOD. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... A FRONTAL BOUNDARY OVER THE SW N ATLC HAS WEAKENED THE SUBTROPICAL RIDGING N OF THE AREA. TROUGHING SHOULD CONTINUE TO COMPROMISE THE SUBTROPICAL RIDGE TODAY...WITH A RETURN OF GALE FORCE WINDS NEAR THE COAST OF COLOMBIA EXPECTED BY LATE TONIGHT/EARLY WED MORNING DURING THE DIURNAL MAXIMA AS STRONG RIDGING RETURNS TO THE WESTERN ATLC. THE 0000 UTC GFS ALREADY CARRIES GALES THIS MORNING...BUT THE 0000 UTC GEFS ONLY SHOWS A 10 PERCENT CHANCE OF GALES AND THE OTHER MODELS WAIT TO ENHANCE THE WINDS LATER IN THE DAY ONCE THE RIDGE BUILDS. THE 0224 UTC ASCAT PASS SUGGESTS THAT THE WIND FIELD HAS WEAKENED CONSIDERABLY COMPARED TO A FEW NIGHTS AGO WHEN THE GALE WAS IN FULL FORCE. WILL CONTINUE WITH THE GALE WARNING BEGINNING WED NIGHT WHEN THE GEFS ALLOWS A 30 PERCENT CHANCE OF GALES. THE GALE WILL PEAK THU MORNING AND DISSIPATE BY SAT AS THE HIGH CENTER MOVES N AND THEN WEAKENS. ELSEWHERE...FRESH TO STRONG TRADES SHOULD BUILD INTO THE NW CARIBBEAN AND THE WINDWARD PASSAGE BEGINNING WED AS THE SUBTROPICAL RIDGE INTENSIFIES ONLY TO DIMINISH FRI INTO THE WEEKEND AS THE HIGH WEAKENS. IN THE TROPICAL N ATLC...THE BROAD AREA OF FRESH TO STRONG WINDS CURRENTLY IN PLACE WILL BEGIN TO DIMINISH WED AND SEAS WILL SUBSIDE AS A LOW PRES SYSTEM DIVES SOUTHEASTWARD INTO THE CENTRAL ATLC AND WEAKENS THE RIDGE THERE. THE ECMWF IS MORE SOUTHWESTERLY WITH THE LOW TRACK THAN THE GFS AND GFS/ECMWF ENSEMBLES. THE GFS WAS USED TO ADJUST THE FORECAST HERE. SW N ATLC S OF 31N W OF 55W... A FRONTAL BOUNDARY FROM 28N70W TO WEST PALM BEACH FLORIDA WILL RETROGRADE NORTHWARD AS IT DISSIPATES TODAY. THE 0228 UTC ASCAT PASS SHOWS FRESH TO STRONG EASTERLY WINDS ARE IN PLACE N OF THE BOUNDARY IN THE REGION N OF 29N. THE CURRENT FORECAST IS TOO WEAK WITH THE WIND FIELD HERE AND WILL BE ADJUSTED ACCORDINGLY. THIS ASCAT PASS ALSO SHOWS FRESH TO STRONG TRADEWINDS S OF 23N TO THE N OF HISPANIOLA AND EASTERN CUBA TO 75W...INCLUDING ATLC APPROACHES TO THE WINDWARD PASSAGE. THESE EASTERLY TRADES ARE EXPECTED TO INTENSIFY TUE AS THE FRONTAL BOUNDARY DISSIPATES AND THE SUBTROPICAL RIDGE BUILDS TO THE N. A SOLID AREA OF STRONG TO NEAR GALE FORCE TRADES IS EXPECTED BETWEEN THE TURKS AND CAICOS AND THE WINDWARD PASSAGE TODAY THROUGH THU WITH SEAS IN THE 8-10 FT RANGE FORECAST. THE AFOREMENTIONED SYSTEM IN THE CENTRAL ATLC BECOMES A PLAYER IN THE STRENGTH OF THE HIGH PRES TO THE N HERE BY FRI...WITH THE GFS PREFERRED WITH THIS SYSTEM. CONDITIONS ABOVE ADVISORY CRITERIA WITH THIS SYSTEM WILL PRIMARILY BE CONFINED TO WATERS E OF 65W FRI AND SAT. THE GFS WAS USED TO ADJUST THE FORECAST HERE. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .GALE WARNING...AMZ031. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER