000 AGXX40 KNHC 270726 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 226 AM EST SAT FEB 27 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: 0000 UTC GFS BLEND WITH PREVIOUS OFFICIAL FORECAST THROUGH MON FOR WINDS...THEN USED A BLEND OF THE 0000 UTC GFS/ECMWF. FOR WAVEHEIGHTS USED BLEND OF 0000 UTC MWW3 WITH PREVIOUS OFFICIAL FORECAST WITH FEW MANUAL ADJUSTMENTS MADE TO WAVES ALONG TEXAS COAST. HIGH CONFIDENCE THROUGH MON...THEN MEDIUM CONFIDENCE TUE THROUGH WED NIGHT. HIGH PRES OF 1029 MB IS CENTERED IN THE NW GULF NEAR 29N93W. CURRENT BUOY OBSERVATIONS AND PARTIAL ASCAT DATA SHOW ANTICYCLONIC FLOW CONSISTING OF GENERALLY LIGHT TO GENTLE WINDS THROUGHOUT...EXCEPT FOR HIGHER WINDS IN THE MODERATE RANGE IN THE FAR SE PORTION EAR THE YUCATAN CHANNEL. THE OBSERVATIONS NOTE SEAS IN THE RANGE OF 4-5 FT S OF LINE FROM 29N84W TO 21N87W...AND LOWER SEAS OF 1-2 FT N...AND NW OF THE SAME LINE. THE MODERATE WINDS IN THE FAR SE PORTION WILL DIMINISH THIS AFTERNOON. CHANGES WILL BE GRADUALLY UNDERWAY THROUGH THE PERIOD AS THE HIGH CENTER OF 1029 MB MOVES EASTWARD THROUGH EARLY NEXT WHILE WEAKENING AS LOW PRES MOVING E THROUGH THE CENTRAL U.S. DRAGS A COLD FRONT OFF THE TEXAS COAST...AND INTO THE NW GULF LATE TUE AFTERNOON OR EARLY EVENING. THE SURFACE LOW PRES ASSOCIATED WITH THIS FRONT QUICKLY TRACKS NE TO THE UPPER OHIO VALLEY BY LATE TUE NIGHT WITH THE COLD FRONT EXTENDING FROM S CENTRAL LOUISIANA TO THE TEXAS/NE BORDER...AND FROM THE FLORIDA PANHANDLE TO THE EASTERN BAY OF CAMPECHE ON WED. THE ECMWF IS FASTER THAN THE GFS AND UKMET WITH THE FRONTAL POSITIONS TUE AND WED. THE GFS IS STRONGEST WITH NORTHERLY WINDS BEHIND THE FRONT. GIVEN THE UNCERTAINTY WITH THE STRENGTH OF THE WINDS...AND WITH TIMING OF THE FRONT THROUGH THE GULF...A GFS/ECMWF BLEND WITH PREVIOUS OFFICIAL SEEMS TO BE THE BEST SOLN FOR THE GRIDS TUE AND WED. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 0000 UTC GFS BLEND WITH PREVIOUS OFFICIAL FORECAST FOR WINDS. FOR WAVEHEIGHTS USED BLEND OF 0000 UTC MWW3 WITH PREVIOUS OFFICIAL ALONG WITH TAFB NWPS WAVE PARAMETERS. HIGH CONFIDENCE. A PERSISTENT FRONTAL SYSTEM EXTENDS AS A COLD FRONT FROM NW HAITI SW TO 19N76W WHERE IT BECOMES STATIONARY SW TO 17N82W ...AND TO INLAND NE HONDURAS. STRONG HIGH PRES IS PRESENT OVER THE NW CARIBBEAN SEA BEHIND THE FRONT. THE 0236 UTC ASCAT PASS NOTED MOSTLY MODERATE TO FRESH NE WINDS W OF THE FRONT AND S OF 20N. A SMALL PATCH OF FRESH NE WINDS IS NOTED OVER THE NORTHERN PART OF THE WINDWARD PASSAGE IN THE ASCAT DATA AS WELL IN AN EARLIER SHIP REPORT. SCATTEROMETER DATA INDICATED MAINLY MODERATE E WINDS THROUGHOUT THE REST OF THE CARIBBEAN...EXCEPT FOR MODERATE TO FRESH N-NE WINDS ELSEWHERE NW OF THE COLD FRONT AND NE-E WIND DIRECTION THROUGH THE TROPICAL N ATLC ZONES. THE COLD FRONT PORTION OF THE FRONTAL SYSTEM IS FORECAST TO BECOME STATIONARY TODAY. THE FRONT WILL BEGIN TO WEAKEN THROUGH TONIGHT. THE FRONT WILL THEN BECOME DIFFUSE SUN AND SUN NIGHT. THE WINDS BEHIND THE FRONT WILL CHANGE LITTLE THROUGH THIS MORNING...THEN DIMINISH BRIEFLY THIS AFTERNOON. THESE WINDS WILL INCREASE AGAIN SAT NIGHT INTO EARLY ON SUN WITH FRESH TO LOCALLY STRONG NE WINDS MATERIALIZING IN THE LEE OF CUBA AND ACROSS THE WINDWARD PASSAGE REGION. THE NE WINDS ARE EXPECTED TO PERSIST THROUGH SUN NIGHT BEFORE BECOMING MODERATE TO FRESH ON MON...AND NE-E LIGHT TO MODERATE TUE AND WED AT WHICH TIME THE PRES GRADIENT WILL HAVE SIGNIFICANTLY SLACKEN ACROSS THE NW AND N CENTRAL CARIBBEAN SEA. SEAS AT THAT TIME ARE FORECAST TO BE RATHER LOW THERE PER WAVEWATCH AND NWPS OUTPUT...IN THE 3-4 FT RANGE SUBSIDING TO 2-3 FT TUE NIGHT AND WED. THE FRESH TO STRONG NE WINDS IN THE S CENTRAL CARIBBEAN AND NEAR THE COAST OF COLOMBIA WILL PULSE...PARTICULARLY DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE STRONGEST WINDS IN THE 25-30 KT RANGE WITHIN ABOUT 60-90 NM OF THE COAST OF COLOMBIA DURING THE FORECAST PERIOD. SEAS WILL BUILD TO 8-10 FT IN THE AREA OF MAXIMUM WINDS. MOSTLY MODERATE E TRADES WILL PERSIST ELSEWHERE THROUGH THE FORECAST PERIOD. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 0000 UTC GFS/MWW3 BLEND WITH PREVIOUS OFFICIAL FORECAST FOR WINDS THROUGH MON...THEN USED A BLEND OF THE ECMWF AND GFS. FOR WAVEHEIGHTS USED BLEND OF 0000 UTC ECMWF WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE...EXCEPT MEDIUM CONFIDENCE NW PART TUE AND WED. A COLD FRONT EXTENDS FROM 31N63W SW TO THE SE BAHAMAS AND TO NW HAITI AT 06Z. A TROUGH BEHIND THE FRONT EXTENDS FROM 31N67W TO THE CENTRAL BAHAMAS AND TO ALONG NW CUBA. THE SYNOPTIC ANALYSIS ALSO DEPICTS STRONG HIGH PRES BUILDING EASTWARD BEHIND THE FRONT. ISOLATED SHOWERS ARE POSSIBLE WITHIN 180 NM AND 120 NM E OF THE FRONT. AN ASCAT PASS FROM 0051 UTC INDICATED THAT FRESH W- NW WINDS ARE W OF THE FRONT TO 70W AND N OF 30N. IT ALSO SHOWED FRESH S-SW WINDS WITHIN ABOUT 120 NM E OF THE FRONT N OF 29N. WINDS ELSEWHERE BEHIND THE FRONT AS NOTED IN THE BUOY OBSERVATIONS AND ASCAT DATA ARE MODERATE NLY...AND GENTLE TO MODERATE E-SE IN DIRECTION SE OF THE FRONT. BUOY OBSERVATIONS ARE SHOWING SEAS IN THE 6-8 FT NE OF THE BAHAMAS...4-5 FT SEAS N OF THE BAHAMAS BETWEEN 78W-80W AND ALSO SW OF THE BAHAMAS...AND LOWER SEAS OF 1-2 FT N OF 27N W OF 80W. THE FRONT WILL STALL AND WEAKEN OVER THE SE WATERS TODAY AND TONIGHT FROM NEAR 25N65W TO NEAR NW HAITI AND WINDWARD PASSAGE. THE TROUGH FOLLOWING IN BEHIND IT WILL ALSO MOVE INTO THE FAR SE WATERS AND MERGE WITH THE WEAKENING BOUNDARY ON SUN AS HIGH PRES FROM THE GULF OF MEXICO SLIDES EASTWARD ACROSS THE FAR NORTHERN WATERS. A TIGHTENING PRES GRADIENT BETWEEN THE ASSOCIATED RIDGE AXIS AND THE FRONTAL BOUNDARY WILL ALLOW FOR MOSTLY FRESH NE WINDS TO DEVELOP IN THE SE PORTION SUN AND SUN NIGHT WITH SEAS IN THE RANGE OF 5-7 FT. THE FRESH W-NW WINDS BEHIND THE FRONT ARE FORECAST TO DIMINISH LATER THIS MORNING WITH THE 6-8 FT SEAS MOVING NE OF THE FORECAST WATERS. THE HIGH PRES OVER THE FAR NORTHERN WATERS WILL REACH TO NEAR 31N68W ON TUE...AND TO WELL NE OF THE AREA WED IN RESPONSE TO A FRONTAL SYSTEM MOVING ACROSS THE EASTERN U.S. SLY FLOW INCREASES IN THE NW PORTION TUE NIGHT AND WED ALONG WITH SEAS BUILDING UP TO AROUND 8 FT. SCATTERED SHOWERS AND TSTMS ARE POSSIBLE IN THE NW PORTION IN ADVANCE OF THE FRONTAL SYSTEM. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.