000 AGXX40 KNHC 051924 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 325 PM EDT FRI APR 5 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 COLD FRONT IS PRESENTLY MAKING HEADWAY ACROSS THE EASTERN GULF. LATEST SURFACE ANALYSIS AND VISIBLE SATELLITE DEPICT THE FRONT EXTENDING FROM NEAR PUNTA GORDA FLORIDA SSW ACROSS THE WESTERN TIP OF CUBA...AND INTO THE NW CARIBBEAN SEA. THE 1452 ASCAT PASS CLEARLY REVEALED WINDS SHIFTING FROM S-SW AHEAD OF THE FRONT TO NW BEHIND IT. SCATTERED TSTMS ACTIVITY IN LINES IS OCCURRING TO THE SE OF THE FRONT ACROSS THE FAR SE GULF AND STRAITS OF FLORIDA. BEHIND THE FRONT HIGH PRES IS BUILDING ESE ACROSS THE AREA...WITH SHALLOW COOLER AIR SPREADING S ACROSS THE GULF. LATEST AND CURRENT BUOY OBSERVATIONS REVEAL THAT SEAS HAVE SUBSIDED IN THE NW PORTION OF THE GULF...BUT REMAIN IN THE 6-8 FT RANGE ELSEWHERE IN THE NW FLOW. FORECAST IS ON TRACK WITH COLD FRONT EXITING THE GULF EARLY THIS EVENING SHUNTING THE TSTM ACTIVITY E OF THE GULF. THE 6-8 FT SEAS WILL SLOWLY SUBSIDE THROUGH THE WEEKEND AS THE HIGH PRES SETTLES IN ACROSS THE AREA. MODELS SHOW THAT THE HIGH PRES WILL SHIFT EASTWARD SAT AND SUN AS LOW PRES DEEPENS OVER THE TEXAS PANHANDLE ALLOWING FOR SOUTHERLY RETURN FLOW TO INCREASE OVER THE WESTERN GULF THROUGH WED. WAVEWATCH SHOWS SEAS BUILDING TO 10 FT OVER THE WESTERN GULF BY WED. THIS SEEMS REASONABLE GIVEN THE EXPECTED DURATION OF THE RETURN FLOW AND LARGE FETCH AREA. FOR THE GRIDDED FORECAST IN THE GULF...I BLENDED THE 12 UTC GFS WITH THE 00 UTC ECMWF FROM LAST NIGHT INTO THE PREVIOUS OFFICIAL GRIDS. ONLY TWEAKS MADE WERE TO HIGHLIGHT SEAS TO 8 FT A LITTLE MORE IN THE FAR SE GULF NEAR THE YUCATAN CHANNEL AND NEAR NW CUBA AREAS. SW N ATLC S OF 31N W OF 55W... THE PRELIMINARY SURFACE ANALYSIS HAS THE NE PORTION OF THE GULF OF MEXICO COLD FRONT EXTENDING FROM 31N76W SW TO INLAND FLORIDA AT CAPE CANAVERAL. HIGH PRES IS OVER THE AREA E OF ABOUT 73W. SCATTERED TO NUMEROUS SHOWERS AND TSTMS WITH GUSTY WINDS ARE OCCURRING OVER A GOOD PORTION OF THE AREA AHEAD OF THE FRONT N OF 27N BETWEEN THE FRONT AND 71W AND N OF 21N W OF 74W TO THE STRAITS OF FLORIDA. LITTLE DEVIATIONS WITH RESPECT TO COLD FRONT POSITIONS OVER THE NEXT 24-48 HRS ARE EXPECTED. WILL FORECAST THE COLD FRONT TO REACH FROM NEAR 31N75W TO WESTERN CUBA THIS EVENING...THEN FROM NEAR BERMUDA TO CENTRAL CUBA SAT...AND FROM NEAR 25N65W TO EASTERN CENTRAL CUBA SUN. SW WINDS OF 20-25 KT ARE EXPECTED AHEAD OF THE FRONT N OF ABOUT 27N WITH WINDS BECOMING N-NE 20-25 KT BEHIND IT N OF 27N. STRONG WINDS OF GALE FORCE ARE FORECAST N OF 31N IN OPC'S AOR. SEAS WILL BE ABOUT 8-10 FT E THE FRONT...AND TO 9 FT BEHIND IT. THE GLOBAL MODELS INCLUDING THE MEAN ENSEMBLE FORECAST FROM THE GFS AND ECMWF ARE CONSISTENTLY DEPICTING LOW PRES FORMING OVER THE NE PORTION OF THE AREA FORECAST WATERS ON SAT WITH THE FRONT. THE GFS DETERMINISTIC AND ENSEMBLE GUIDANCE REMAINS ON A SLIGHTLY MORE NORTHERN LOCATION WITH THE LOW THAN THE ECMWF DETERMINISTIC AND MEAN ENSEMBLE GUIDANCE. THE NAVGEM CAGIP MODEL GUIDANCE IS SIMILAR TO THE ECMWF GUIDANCE WITH THE LOW. FOR THIS FORECAST WILL FORECAST THE LOW NEAR 30N71W IN ABOUT 24 HRS...AND TO NEAR 31.5N AT 61W IN 48 HRS BEFORE IT LIFTS FURTHER N AWAY FROM THE REGION WITH THE FRONT GRADUALLY WEAKENING OVER THE SE PORTION. MODELS AGREE THAT HIGH PRES THEN BUILDS WESTWARD OVER THE NORTHERN PORTION INTO TUE...AND BECOMES THE MAIN FEATURE INFLUENCING THE WIND REGIME THROUGH DAY 5. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... THE ASCAT PASS FROM 1454 UTC THIS MORNING SHOWED NE-E WINDS OF 20- 25 KT OVER THE SOUTHERN PORTION OF THE CENTRAL CARIBBEAN. A FEW SHIP OBSERVATIONS ALSO SHOWING THESE SAME KIND OF WINDS. THE E- SE WINDS OF 20-25 KT IN THE GULF OF HONDURAS HAVE DIMINISHED WITH THE GULF OF MEXICO COLD FRONT NOW HAVING ENTERED THE FAR NW CARIBBEAN SEA AS NICELY SEEN ON SATELLITE IMAGERY. WINDS IN THE NW CARIBBEAN ARE SE-S AT 10 KT AHEAD OF THE FRONT WHICH EXTENDS FROM WESTERN CUBA TO THE WESTERN GULF OF HONDURAS. THE SAME ASCAT PASS NICELY CAUGHT THE WIND SHIFT ACROSS THE FRONT. WINDS ELSEWHERE ACROSS THE CARIBBEAN AND TROPICAL N ATLC ARE LIGHT TO MODERATE E-SE IN DIRECTION. HIGH PRES CENTERED NE OF THE AREA WITH A WEAK SURFACE TO LOW LEVEL TROUGH ALONG 62W FROM GUADELOUPE N TO 21N IS ENHANCING TRADE WINDS OVER THE NE PORTION OF THE TROPICAL NW ATLC WITH SEAS TO 9 FT THERE PRIMARILY IN A NE SWELL. THE AFOREMENTIONED GULF OF MEXICO COLD FRONT IS FORECAST TO WEAKEN AND GRADUALLY DISSIPATE AS IT MOVES SE ACROSS THE NW CARIBBEAN THROUGH LATE SAT NIGHT. THE TROUGH ALONG 62W WILL REACH TO NEAR 65W BY EARLY SAT...AND TO NEAR THE EASTERN PART OF THE DOMINCAIN REPUBLIC BY EARLY SUN BEFORE IT WASHES OUT AS IT MOVES WNW. THE TIGHT GRADE=IENT WILL SLACKEN THROUGH SAT. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. EFFECTIVE 20 MARCH 2013...TAFB GRIDDED MARINE FORECASTS FOR 10-M WINDS...10-M WIND GUSTS...SIGNIFICANT WAVE HEIGHTS AND HAZARDS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) ON AN EXPERIMENTAL BASIS AT: HTTP://PREVIEW.WEATHER.GOV/GRAPHICAL ADDITIONAL INFORMATION IS AVAILABLE AT WWW.NWS.NOAA.GOV/OM/NOTIFICATION/PNS13OFFSHORE_HIGHSEAS.HTM NOTE...GRIDDED MARINE FORECASTS AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WILL BE DISCONTINUED ONCE THE "OCEANIC" VIEW IS ADDED TO THE EXPERIMENTAL NDFD GRAPHICAL INTERFACE. $$ FORECASTER AGUIRRE