000 AGXX40 KNHC 090740 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 240 AM EST WED JAN 09 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... DOPPLER RADAR SHOWS A NORTH-SOUTH SQUALL LINE BEGINNING TO FORM ALONG 96W AHEAD OF THE DEEP-LAYER LOW MOVING THROUGH THE NORTH CENTRAL MEXICO. BUOY 42020 IS REPORTING 20 KT SE WINDS AND 10 FT SEAS BEHIND THE SQUALL...WITH ELEVATED PLATFORMS BRIEFLY SHOWING WINDS AS HIGH AS 40 KT AS THE SQUALL APPROACHES. THE 0358 UTC ASCAT PASS HAD A FEW 30 KT RETRIEVALS...BUT THE SW WIND DIRECTION LOOKS SPECIOUS AS IT DOES NOT AGREE WITH THE LAND-BASED OBSERVATIONS. THIS IS A STRONG DEEP-LAYER LOW. WINDS AND SEAS SEEM TO MATCH BETTER WITH THE STRONGER 0000 UTC ECMWF/EC WAVE MODEL COMPARED TO THE GFS INITIALLY. BY 1800 UTC TODAY...THESE MODELS COME INTO BETTER AGREEMENT. AT THE SAME TIME TOMORROW...THE GFS CARRIES A STRONGER VORT ON THE SE SIDE OF THE LOW FROM THE GULF INTO SE LOUISIANA. THE GFS SHOWS HIGHER WINDS ALONG THE N CENTRAL GULF COAST COMPARED TO THE ECMWF AS A RESULT...POSSIBLY DUE TO GRID-SCALE FEEDBACK. HOWEVER...WITH THE STRONG LOW-LEVEL SOUTHERLY JET EXPECTED TO BE IN PLACE AHEAD OF THE FRONT OVERNIGHT THU NIGHT...DO NOT WISH TO BACK OFF TOO MUCH ON THE GFS FORECAST. THE FRONTAL BOUNDARY DISSIPATES OVER THE GULF FRI AS THE LOW LIFTS WELL N OF THE AREA AND DEEP-LAYER RIDGING BUILDS OVER THE CENTRAL AND EASTERN GULF. A BROAD UPPER TROUGH BEGINS TO WORK ITS WAY INTO THE WESTERN GULF LATE FRI INTO SAT. THE GFS CARRIES THE ASSOCIATED COLD FRONT TO THE TEXAS COAST BY 1800 UTC SUN WHILE THE FASTER ECMWF HAS IT THERE BY 0600 UTC SUN. THE NOGAPS AND UKMET ARE FASTER THAN BOTH MODELS. WILL LEAN THE FORECAST TOWARD THE MORE MIDDLE-OF-THE-ROAD GFS WITH THIS FRONT AS WELL AS WITH THE FORECAST TONIGHT THROUGH FRI...WHILE USING THE BETTER INITIALIZED ECMWF TO ADJUST THE NOW-CAST AND FORECAST FOR TODAY. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... THE 0204 UTC ASCAT PASS SHOWS WINDS NEAR GALE FORCE OFF THE COAST OF COLOMBIA. AS ASCAT GENERALLY RUNS AROUND 5 KT TOO LOW WITH WINDS AT THIS SPEED AND THE DIURNAL MAXIMA OCCURRING AFTER THE PASS TIME...A GALE WARNING IS IN EFFECT HERE AND WILL CONTINUE UNTIL MIDDAY FRI WHEN THE RIDGING OVER THE SW N ATLC BEGINS TO WEAKEN. THE 0000 UTC GEFS SHOW NO CHANCE OF A GALE FROM FRI AFTERNOON ONWARD. ELSEWHERE...FRESH TO STRONG TRADES WILL BUILD INTO THE NW CARIBBEAN AND THE WINDWARD PASSAGE BEGINNING TODAY AS THE SUBTROPICAL RIDGE INTENSIFIES ONLY TO DIMINISH FRI INTO THE WEEKEND AS THE HIGH IN THE SW N ATLC WEAKENS. IN THE TROPICAL N ATLC...THE BROAD AREA OF FRESH TO STRONG WINDS CURRENTLY IN PLACE WILL BEGIN TO DIMINISH LATE TODAY AND TONIGHT...WITH SEAS SUBSIDING AS A LOW PRES SYSTEM DIVES SOUTHEASTWARD INTO THE CENTRAL ATLC AND WEAKENS THE SUBTROPICAL RIDGE THERE. THE EC WAVE IS FASTER CARRYING THE SWELL S INTO THE TROPICAL ATLC THAN THE GFS WHICH IS IN BETTER AGREEMENT WITH THE NCEP/FNMOC ENSEMBLE MEAN WITH THE TIMING OF THE LEADING EDGE OF THE SWELL. SW N ATLC S OF 31N W OF 55W... THE WEAK FRONTAL BOUNDARY THAT EXTENDS ALONG 30N WILL LIFT N OF THE AREA TODAY. THE 0206 UTC ASCAT PASS SHOWS FRESH TO STRONG TRADEWINDS S OF 24N N OF THE ANTILLES TO EASTERN CUBA AND FRESH SE WINDS INTO THE STRAITS OF FLORIDA WHILE THE 0414 UTC OSCAT PASS SHOWED STRONG WINDS IN THE ATLC APPROACHES TO THE WINDWARD PASSAGE. A SOLID AREA OF STRONG TO NEAR GALE FORCE TRADES IS EXPECTED BETWEEN THE TURKS AND CAICOS AND THE WINDWARD PASSAGE TODAY THROUGH THU NIGHT WITH SEAS IN THE 8-10 FT RANGE FORECAST TO DIMINISH AS THE SW N ATLC RIDGING WEAKENS. THE AFOREMENTIONED SYSTEM IN THE CENTRAL ATLC BECOMES A PLAYER PRIMARILY OVER WATERS E OF 65W FRI INTO THE WEEKEND. AS MENTIONED IN THE SECTION ABOVE...THE 0000 UTC WW3 AGREES BEST WITH THE NCEP/FNMOC ENSEMBLE MEAN WITH THE TIMING OF THE LEADING SOUTHERN EDGE OF THE SWELL...BUT THE GFS IS CONSIDERABLY SLOWER THAN THE ENSEMBLE TO SPREAD THE SWELL WESTWARD. THE 0000 UTC ECMWF IS SLIGHTLY FASTER THAN THE GFS TO BRING IN THE STRONGEST WINDS...INCLUDING GALES JUST E OF THE AREA. A BLEND OF THE GFS/ECMWF AS WELL AS THEIR WAVE MODELS WILL BE USED TO ADJUST THE MODELS. 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