000 AGXX40 KNHC 201856 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 200 PM EST WED FEB 20 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 1200 UTC GFS IS APPROXIMATELY 5 KT TOO WEAK WITH THE WINDS IN THE NW GULF COMPARED TO BUOY OBSERVATIONS AND THE 0552 UTC OSCAT PASS. THE WW3 WAS ALSO RUNNING ABOUT 2 FT TOO LOW WITH SEAS AT BUOYS 42019 AND 42020 AT 1200 UTC. ADJUSTMENTS WERE MADE HERE AND IN THE N CENTRAL GULF WHERE THE GFS AND WW3 WERE ALSO TOO WEAK COMPARED TO OBSERVATIONS. THE STRONG SE RETURN FLOW WILL CONTINUE TO EXPAND OVERNIGHT IN THE NW GULF AS THE PRESSURE GRADIENT BUILDS BETWEEN RIDGING OVER THE EASTERN GULF AND DEEPENING LOW PRESSURE OVER TEXAS. THE WEAK WARM FRONT CURRENTLY STRETCHING FROM NEAR NAPLES FLORIDA TO THE CENTRAL TEXAS COAST WILL STRENGTHEN OVER THE NW GULF BEFORE LIFTING ONSHORE THU. THE WW3 IS LIKELY TOO LOW WITH SEAS INTO THE FORECAST PERIOD BASED ON ITS POOR PERFORMANCE INITIALLY. THE NEXT COLD FRONT WILL PUSH OFF THE TEXAS COAST THU NIGHT 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 SAT NIGHT BEFORE LIFTING BACK N AS A WARM FRONT SUN. THERE IS GENERALLY GOOD AGREEMENT AMONG THE MODELS ON THIS SCENARIO. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... 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 AND WAS USED TO ADJUST THE FORECAST IN THE SHORT TERM. THE EC WAVE ALSO APPEARED TO BE SLIGHTLY BETTER WITH THE HIGHER SEAS SEEN IN THE MIXING E AND NW SWELL IN THE NORTHERN PORTION OF THE TROPICAL N ATLC THIS MORNING COMPARED TO THE 1200 UTC WW3. HIGH PRES CENTERED N-NE OF AREA NEAR 30N50W WILL CONTINUE TO SHIFT EASTWARD THROUGH THU AHEAD OF THE COLD FRONT MOVING OFF THE US EAST COAST. 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 RELAX THROUGH THU AFTERNOON AND ALLOW THE AREA OF STRONG EASTERLY TRADE WINDS OVER THE CENTRAL CARIBBEAN TO CONTRACT. THE 1104 UTC WINDSAT PASS SHOWED ONE BARB TO GALE FORCE THIS MORNING JUST OFF THE COAST OF COLOMBIA WITH THE 1506 UTC ASCAT PASS SHOWING WINDS TO 30 KT. WINDS WERE LIKELY AT GALE FORCE HERE EARLY THIS MORNING...BUT THEY HAVE BEGUN TO DIMINISH AS THE PRESSURE GRADIENT WEAKENS. HIGH PRESSURE TO THE N WILL BUILD BEHIND ANOTHER SW N ATLC COLD FRONT THU NIGHT AND SHIFT SOUTHEASTWARD TO 27N52W THROUGH LATE SUN AHEAD OF A THIRD COLD FRONT. 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 INTO SUN. SW N ATLC S OF 31N W OF 55W... THE 1200 UTC WAS ABOUT 1 FT TOO LOW WITH SEAS N OF PUERTO RICO AND THE DOMINICAN REPUBLIC COMPARED TO OBSERVATIONS. IT APPEARS TO BE SUBSIDING THE NORTHERLY SWELL HERE A BIT TOO QUICKLY. THE EC WAVE MODEL COMPARED BETTER TO OBSERVATIONS INITIALLY AND WAS USED TO ADJUST THE FORECAST IN THE SHORT TERM. THE 1502 UTC ASCAT PASS SHOWS THE FRESH TO STRONG WINDS AHEAD OF THE COLD FRONT FROM 31N71W TO WEST PALM BEACH FLORIDA ARE RETREATING N OF THE FORECAST AREA. THUNDERSTORMS ALONG THE FRONT HAVE DIMINISHED. A WEAK PRE-FRONTAL TROUGH LIES APPROXIMATELY 210 NM SE OF THE FRONT...WITH SHOWERS LYING PRIMARILY TO ITS EAST N OF 25N. THE FRONT WILL CONTINUE E OF 65W BY THU...LEAVING RELATIVELY TRANQUIL CONDITIONS OVER THE SW N ATLC. BY THU NIGHT...A NEW SURGE OF COLD AIR WILL REINFORCE THE FRONT OVER NE WATERS AND BRING WINDS TO 30 KT AND SEAS AS HIGH AS 18 FT IN NW SWELL FRI BEFORE SUBSIDING. RETURN FLOW WILL PICK UP TO A STRONG BREEZE IN THE NW PORTION 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. 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... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER