000 AGXX40 KNHC 200629 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 229 AM EDT WED MAR 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... A STATIONARY FRONT EXTENDS FROM JUST N OF TAMPA BAY FLORIDA TO 25N89W TO NEAR BROWNSVILLE TEXAS. UPPER LEVEL ENERGY IS CURRENTLY ROUNDING THE BASE OF A TROUGH OVER THE E GULF HELPING TO RE-INITIALIZE HEAVY CONVECTION NEAR THE FRONT BETWEEN THE WFO TBW COASTAL WATERS AND 88W. MEANWHILE A REINFORCING COLD FRONT IS MAKING ITS WAY TOWARD THE GULF SHORELINES FROM THE NW. THIS NEW FRONT WILL EXTEND FROM 30N87W TO 28N92W TO 27N98W JUST AFTER SUNRISE...OVERTAKING/MERGING WITH THE OLD STATIONARY FRONT AND REACHING FROM 29N83W TO 25N90W TO 25N98W THIS AFTERNOON...THEN FROM 26N82W TO 23N90W TO 21N97W LATE TONIGHT...BECOMING DIFFUSE OVER THE SE GULF JUST PRIOR TO ITS EXIT BY EARLY THU. FRESH TO STRONG NE WINDS ARE STILL ANTICIPATED BEHIND THE REINFORCING FRONT WHICH WILL BUILD SEAS TO AT LEAST 8-9 FT...DIMINISHING AND SUBSIDING BY THU MORNING AS THE FRONT LOSES DEFINITION. IT IS INTERESTING TO NOTE THAT SREF 34 KT PROBABILITIES ARE 15-30% ACROSS THE NORTHERN GULF ZONES (GMZ011-015) THROUGH THE DAY TODAY...AND A FEW GUSTS TO GALE FORCE CANNOT BE RULED OUT. HIGH PRES BUILDS IN FROM THE NW-N BEHIND FRONT FRONT THU... SLIDING E TO OVER THE CAROLINAS THU NIGHT ALLOWING FOR MODERATE SOUTHERLY RETURN FLOW TO SET UP ACROSS THE GULF WATERS. LITTLE CHANGE IS THEN FORECAST THROUGH FRI...WITH RETURN FLOW INCREASING TO FRESH TO STRONG FRI NIGHT INTO SAT. MODEL GUIDANCE HAS NOW REVERSED COURSE AND HAS SPED UP THE TIMING/ARRIVAL OF THE NEXT COLD FRONT WHICH IS NOW (ONCE AGAIN) FORECAST TO ENTER THE NW GULF COASTAL WATERS SAT AFTERNOON... REACHING FROM THE WESTERN FLORIDA PANHANDLE TO THE SW GULF SUN MORNING WHERE IT WILL STALL...BEING OVERTAKEN BY A REINFORCING FRONT BY MON MORNING WHICH WILL REACH FROM NEAR TAMPA BAY FLORIDA TO TAMPICO MEXICO BY SUNRISE MON. ANOTHER ROUND OF FRESH TO STRONG NE WINDS IS CURRENTLY EXPECTED BEHIND THIS REINFORCING FRONT...HOWEVER GIVEN THE FLIP-FLOPPING OF THE MODEL GUIDANCE WITH THESE WEEKEND FRONTS...MUCH UNCERTAINTY REMAINS WITH RESPECT TO THE TIMING AND STRENGTH OF ANY NORTHERLY WINDS BEHIND THE BOUNDARIES. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... MODERATE EASTERLY WINDS DOMINATE BOTH THE CARIBBEAN AND TROPICAL N ATLC BASINS. THE ONLY NOTICEABLE EXCEPTIONS ARE LOCALLY FRESH WINDS IN THE GULF OF HONDURAS...AND LINGERING FRESH TO STRONG WINDS NEAR THE COAST OF COLOMBIA WHICH ARE ACCOMPANIED BY 8 FT SEAS. ANY REMAINING STRONG NE-E WINDS WILL DIMINISH LATER THIS MORNING AS LOW PRES OVER NW COLOMBIA WEAKENS AND AS HIGH PRES N- NE OF THE REGION BACKS AWAY FURTHER TO THE NE-E. TRANQUIL MARINE CONDITIONS ARE THEN ANTICIPATED ACROSS THE CARIBBEAN THROUGH THE REMAINDER OF THIS WEEK...WITH 1-3 FT SEAS IN THE LEE OF CUBA AND 3-5 FT ELSEWHERE IN THE CARIBBEAN. E-SE WINDS INCREASE TO FRESH TO STRONG IN THE GULF OF HONDURAS/ AMZ017 FRI NIGHT AS RIDGING NE OF CUBA RETURNS EXPANDING TO THE N/AMZ011 BY SAT NIGHT. FRESH TO STRONG WINDS WILL ALSO RETURN TO NEAR THE COAST OF COLOMBIA DURING THIS SAME TIME PERIOD WITH LOW PRES OVER NW COLOMBIA DEEPENING. MEANWHILE...SEAS IN THE TROPICAL N ATLC WILL NOT VARY MUCH THROUGH THE FORECAST PERIOD...5-7 FT IN MIXED NORTHERLY AND EASTERLY SWELL. SW N ATLC S OF 31N W OF 55W... A RIDGE EXTENDING FROM 1021 MB HIGH PRES NEAR 29N54W TO THE EASTERN OFFSHORE WATERS IS WEAKENING AHEAD OF A WEAKENING COLD FRONT NOW DRAPED ACROSS THE NW ZONES FROM NEAR 31N74W TO JUST N OF WEST PALM BEACH FL. THIS FRONT WILL STALL FROM NEAR BERMUDA TO THE CENTRAL BAHAMAS BY THIS AFTERNOON...AWAITING THE ARRIVAL OF A REINFORCING COLD FRONT. THAT NEW FRONT WILL REACH FROM NEAR 31N73W TO 28N77W TO 26N80W LATE TONIGHT WITH LOW PRES POSSIBLY DEVELOPING FROM NEAR 30N/31N BETWEEN 75W/77W BEFORE JETTING OFF NE OF 31N. FRESH TO STRONG WINDS ARE EXPECTED BOTH AHEAD OF AND BEHIND THE FRONT N OF 27N/28N...ALTHOUGH THE DETERMINISTIC GFS INDICATES GALE FORCE WINDS NEAR THE LOW LATE TONIGHT INTO EARLY THU. CURRENTLY THE GFS IS AN OUTLIER WITH RESPECT TO GALE FORCE WINDS WITH THE 00 UTC UKMET AND ECMWF SOLUTIONS SHOWING 30 KT AT BEST ALONG 31N. GEFS 34 KT PROBABILITIES ARE 20% OVER AMZ113-115 N OF 30N...WHILE THE SREF 34 KT PROBABILITIES ARE 10-15% N OF 28N. THE 06 UTC AND 12 UTC GUIDANCE WILL NEED TO BE MONITORED IN CASE A GALE WARNING IS REQUIRED FOR LATE WED NIGHT INTO EARLY THU. THE FRONT WILL SHIFT E REACHING FROM 31N58W TO 28N61W TO 21N70W LATE THU NIGHT...WHEN YET ANOTHER REINFORCING FRONT WILL DEVELOP AND EXTEND FROM NEAR 31N66W TO 28N74W AT THAT TIME. HIGH PRES BUILDS IN ACROSS THE SW N ATLC OFFSHORES FRI...SETTLING TO NEAR 28N74W BY SAT MORNING THEN SHIFTING E OF 65W SUN MORNING AS THE NEXT POTENTIAL FRONTAL SYSTEM INTRUDES FROM THE W-NW. MODEL GUIDANCE KEEPS MOST OF THE ASSOCIATED ENERGY WITH THIS FRONT N OF 31N AS A RIDGE EXTENDING FROM THE AFOREMENTIONED HIGH ATTEMPTS TO POKE INTO THE AREA FROM THE E ALONG 24N/25N... ALTHOUGH RETURN FLOW OF 20-25 KT DOES LOOK LIKELY AT THIS TIME N OF 27N SUN THROUGH EARLY MON AHEAD OF THE FRONT. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE THROUGH 12 UTC AT: WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE AT 12 UTC GRIDDED MARINE DATA WILL BE TRANSITIONED TO AND BECOME AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) ON AN EXPERIMENTAL BASIS AT: HTTP://PREVIEW.WEATHER.GOV/GRAPHICAL 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 LEWITSKY