000 AGXX40 KNHC 211930 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EST THU FEB 21 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... THE 1622 ASCAT PASS SHOWS SE WINDS HAVE DIMINISHED TO 20-25 KT IN THE NW GULF. THE 1200 UTC GFS SHOWS THE STRONGEST WINDS FARTHER S THAN THE ASCAT PASS AND OBSERVATIONS REVEAL. IN ADDITION...THE 1200 UTC WW3 WAS ALSO RUNNING ABOUT 1-2 FT TOO LOW WITH SEAS AT BUOYS 42019 AND 42020 INITIALLY. ADJUSTMENTS WERE MADE HERE TOWARD BOTH THE WIND AND SEA THE OBSERVATIONS. THE WEAK WARM FRONT CURRENTLY STRETCHING FROM NEAR TARPON SPRINGS FLORIDA TO NEW ORLEANS LOUISIANA WILL STRENGTHEN OVER THE NW GULF BEFORE LIFTING INLAND TONIGHT. THE NEXT COLD FRONT WILL PUSH OFF THE TEXAS COAST TONIGHT AND WINDS WILL WEAKEN OVER THE GULF AS THE STRONGEST PRESSURE GRADIENT LIFTS N OF THE AREA. THE WEAK FRONT WILL GRADUALLY MAKE ITS WAY SOUTHEASTWARD FROM CENTRAL FLORIDA TO THE CENTRAL BAY OF CAMPECHE SUN BEFORE LIFTING BACK N AS A WARM FRONT LATE SUN INTO MON. THE 1200 UTC GFS AND ECMWF HAVE TRENDED SLOWER WITH THIS FRONT THAN THEIR RUNS FROM THIS TIME YESTERDAY. ADJUSTMENTS WERE MADE TO THE FORECAST BASED ON THE LATEST GFS/ECMWF FROM SAT ONWARD. BOTH MODELS AGREE ON TAKING THE NEXT COLD FRONT OFF THE TEXAS COAST MON MORNING...WITH NEAR GALE OR MINIMAL GALE CONDITIONS EXPECTED BEHIND THE FRONT NEAR THE COAST OF VERACRUZ LATE MON. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... ONCE AGAIN...SEAS AT BUOY 42057 AND 42058 WERE APPROXIMATELY 3 FEET LOWER THAN THE WW3 AT 1200 UTC. THE 0000 UTC EC WAVE MODEL SHOWED BETTER AGREEMENT WITH THE SEAS HERE...BUT WAS STILL 1-2 FEET TOO HIGH. SHORT-TERM FORECAST SEAS WERE LOWERED HERE TO BE IN BETTER AGREEMENT WITH THE OBSERVATIONS. EARLIER SHIP OBSERVATION NEAR THE GULF OF HONDURAS REPORTED SEAS TO 9 FT DURING THE EARLY MORNING DIURNAL PEAK IN SE WINDS. THERE HAVE BEEN NO WAVE OBSERVATIONS SINCE...BUT WINDS AT JUAN GALVEZ AIRPORT ON ROATAN WERE E-SE AT 20 KT AT 1200 UTC AND STILL SE AT 20 KT AT 1500 UTC. BELIEVE THE WINDS AND SEAS MET ADVISORY CRITERIA THIS MORNING AND SHOULD CONTINUE TO DO SO IN THE MORNING HOURS THROUGH MON BEFORE DIMINISHING AS A COLD FRONT APPROACHES FROM THE N. HIGH PRES CENTERED N OF THE AREA WILL BUILD OVER THE NEXT FEW DAYS BEHIND COLD FRONT MOVING E AWAY FROM THE SW N ATLC. LOW PRES OVER NORTHERN COLOMBIA WILL REMAIN NEARLY STATIONARY DUE TO LOCAL GEOGRAPHIC EFFECTS. AS A RESULT...THE PRES GRADIENT OVER THE REGION WILL GRADUALLY STRENGTHEN TONIGHT AND FRI AND ALLOW THE AREA OF STRONG EASTERLY TRADE WINDS OVER THE CENTRAL CARIBBEAN TO BECOME A MINIMAL GALE IN THE EARLY MORNING HOURS OVERNIGHT TONIGHT THROUGH SUN MORNING. YESTERDAY MORNING...SCATTEROMETER SHOWED A GALE HERE WHILE THE GFS ONLY HAD 30 KT OF WIND. WHILE WINDS AND SEAS HAVE TEMPORARILY DIMINISHED...THE 1200 UTC GFS SHOWS GALES OFF THE COAST OF COLOMBIA OVERNIGHT TONIGHT THROUGH SUN MORNING. THE GFS HAS A TENDENCY TO BE UNDERDONE HERE...SO A GALE WARNING WAS ISSUED FOR THE AREA. HIGH PRESSURE TO THE N WILL SHIFT SOUTHEASTWARD TO 31N55W THROUGH SUN AHEAD OF ANOTHER COLD FRONT IN THE SW N ATLC. FRESH TRADE WINDS WILL PREVAIL ELSEWHERE THROUGH SUN. LARGE LONG-PERIOD N SWELL WILL REACH THE NORTHERN PART OF TROPICAL N ATLC SAT...AND SPREAD SOUTHWARD INTO CARIBBEAN PASSAGES SAT NIGHT THROUGH TUE. SW N ATLC S OF 31N W OF 55W... THE 1200 UTC WW3 WAS ABOUT 1-2 FT TOO LOW WITH SEAS NE OF PUERTO RICO COMPARED TO THE 1542 UTC JASON1 PASS. IT APPEARS TO BE SUBSIDING THE NORTHERLY SWELL HERE A BIT TOO QUICKLY. THE 0000 UTC EC WAVE MODEL COMPARED BETTER TO OBSERVATIONS INITIALLY AND WAS USED TO ADJUST THE FORECAST IN THE SHORT TERM. THE 1300 UTC AND 1440 UTC ASCAT PASSES SHOWED THE FRESH TO STRONG WINDS NEAR THE COLD FRONT FROM 31N58W TO 26N69W HAVE SHIFTED N OF AREA. THE FRONT WILL CONTINUE E OF 65W TONIGHT...BUT A NEW SURGE OF COLD AIR WILL REINFORCE THE FRONT OVER NE WATERS AND BRING STRONG TO GALE FORCE WINDS AND SEAS TO 20 FT OVER NE WATERS BY FRI AFTERNOON...WELL E OF THE SW N ATLC OFFSHORES AREA. RETURN FLOW WILL PICK UP TO A STRONG BREEZE IN THE NW PORTION OVERNIGHT FRI NIGHT AHEAD OF THE NEXT COLD FRONT THAT WILL MOVE OFF THE N FLORIDA COAST SAT NIGHT. THE FRONT WILL STRETCH FROM NEAR BERMUDA TO CENTRAL FLORIDA BY LATE SUN. STRONGEST WINDS AND SEAS IN THE 8-10 FT RANGE WILL SHIFT E WITH THE FRONT. ANOTHER FRONT IS EXPECTED TO MOVE OFFSHORE INTO NW WATERS TUE. A BLEND OF THE GFS AND ECMWF WAS USED TO ADJUST THE FORECAST FROM SAT ONWARD TO ACCOUNT FOR UNCERTAINTY. 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 FROM 11N TO 13N BETWEEN 74W AND 77W....AMZ031. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER