000 AGXX40 KNHC 230748 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 340 AM EDT MON APR 23 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... WEATHER CONDITIONS ACROSS THE AREA ARE CONTINUING TO ABATE NOW THAT THE RECENT NRN GULF LOW PRES AND ASSOCIATED COLD FRONT HAVE EXITED THE REGION. A 1019 MB HIGH CELL IS ANALYZED OVER THE FAR WRN GULF NEAR 27N95W WITH A RIDGE EXTENDING SE ACROSS THE YUCATAN PENINSULA AND INTO THE FAR WRN CARIBBEAN SEA. A SECONDARY COLD FRONT...NOTED AS A DRY TYPE (SECONDARY SURGE OF DRY NLY FLOW) IS JUST INLAND THE LOUISIANA...MISSISSIPPI AND ALABAMA COASTS EARLY THIS MORNING. BUOY OBSERVATIONS FROM ACROSS THE GULF SHOW NW WINDS OF 20 KT E OF ABOUT 88W...NW-N WINDS OF 10-15 KT BETWEEN 88W AND 92W...AND MUCH LIGHTER NLY WINDS OF 10-15 KT S OF 26N W OF 88W AND W-NW 10-15 KT N OF 26N W OF 88W EXCEPT SW 5-10 KT IN THE FAR WRN PORTION ALONG THE TEXAS COAST. A PARTIAL ASCAT PASS FROM 0348 UTC LAST NIGHT NICELY CORROBORATED THESE WIND SPEEDS. THE BUOY OBSERVATIONS ARE REPORTING GRADUALLY LOWERING SEAS IN THE RANGE 6-8 FT S OF 27N BETWEEN 85W-89W...8-10 FT IN A NW SWELL E E OF 85W...AND 3-5 FT ELSEWHERE EXCEPT 2-4 FT IN THE FAR WRN PORTION. MODELS IN GOOD AGREEMENT THAT THE SECONDARY COLD FRONT WILL QUICKLY PUSH SE ACROSS THE ERN AND CENTRAL GULF TODAY AND TONIGHT BRINGING YET ANOTHER SURGE OF NLY 20 KT WINDS TO THOSE WATERS. THIS SECOND FRONT WILL QUICKLY EXIT THE GULF EARLY THIS EVENING AS THE HIGH CENTER IN THE WRN GULF SHIFTS SOME TO THE E. NLY WINDS IN THE CENTRAL AND ERN GULF THEN DIMINISH TO 10-15 KT LATE TONIGHT INTO TUE WITH SEAS THERE SUBSIDING TO 5-7 FT. ELSEWHERE SEAS CHANGE LITTLE INTO TUE. THE HIGH WILL THEN SHIFT FURTHER E TO NEAR 26.5N88.5W BY EARLY TUE NIGHT...AND TO CENTRAL FLORIDA BY WED. AS THIS HAPPENS...SE RETURN FLOW WILL SET UP IN THE FAR WRN GULF WITH INCREASING WIND SPEEDS DUE TO THE TIGHTENING PRES GRADIENT BETWEEN THE HIGH AND DEEPENING LOW PRES IN THE SRN PLAINS. SEAS BUILD TO 6-8 FT IN THE FAR WRN GULF WATERS WED AND TO 7-10 FT THU AND FRI WITH THE HIGHEST OF THE SEAS VERY NEAR THE TEXAS COAST. SW NORTH ATLC S OF 31N W OF 65W... THE COLD FRONT THAT WAS ACROSS THE GULF OF MEXICO 24 HRS AGO HAS SINCE PUSHED ACROSS THE WRN PORTION OF THE ATLC...AND HAS REACHED A PSN FROM NEAR 31N70W SW TO 25N73W TO ACROSS ERN CUBA AND INTO THE CARIBBEAN SEA. A SECONDARY COLD FRONT... NOTED MORE AS A REINFORCING BOUNDARY...HAS ALSO PUSHED INTO THE AREA AND EXTENDS FROM 31N75W SW TO E CENTRAL FLORIDA. A TROUGH IS IN BETWEEN BOTH FRONTS EXTENDING FROM NEAR 31N71W SW TO THE CENTRAL BAHAMAS. BOTH ASCAT DATA FROM LAST NIGHT ALONG WITH RECENT AND CURRENT BUOY OBSERVATIONS REVEAL THAT A TIGHT PRES GRADIENT CONTINUES TO BE IN PLACE OVER THE FAR NE PART OF THE AREA E AND NE OF COLD FRONT PRIMARILY IN ZONE AMZ115 WHERE SLY WINDS OF 25-30 KT ARE NOTED. THE PARTIAL ASCAT PASS FROM JUST 0206 UTC LAST NIGHT SHOWED W-NW WINDS OF 20 KT OVER THE FAR WRN WATERS W OF THE TROUGH...AND NW WINDS OF 20-25 KT TO THE W OF THE SECONDARY COLD FRONT. LIGHTER SE 15-20 KT WINDS ARE ELSEWHERE TO THE E OF THE FIRST FRONT...AND SW 15-20 KT BETWEEN THE FIRST FRONT AND THE TROUGH. MAX SEAS ARE IN THE RANGE OF 9-12 FT ARE OBSERVED IN THE FAR N NE WATERS..AND 6-8 FT ELSEWHERE EXCEPT 3-5 FT IN THE FAR SRN PORTION E OF THE BAHAMAS. NWP MODELS DEPICT THE FIRST COLD FRONT TO SLOW DOWN AS IT APPROACHES FROM NEAR 31N70W TO WINDWARD PASSAGE EARLY TONIGHT...THEN BEGIN TO WEAKEN AND SLOW DOWN AS IT REACHES A POSITION FROM NEAR 31N68W TO 24N71W THEN WEAKENING NEAR WRN HAITI/WINDWARD PASSAGE BY EARLY TUE MORNING...FROM NEAR 25N65W TO HAITI EARLY TUE EVENING...FROM 24N65W TO THE DOMINICAN REPUBLIC BY EARLY WED MORNING...THEN WEAKEN FURTHER INTO A FRONTAL TROUGH OVER THE FAR SE WATERS LATE WED AND THU. THE TROUGH THEN BEGINS TO TRACK BACK W THU AND FRI S OF 25N AS THE REMAINDER OF THE TROUGH SLOWLY SHIFTS E OF THE AREA. THE SECONDARY COLD FRONT WILL QUICKLY REACH FROM NEAR 31N73W TO THE STRAITS OF FLORIDA EARLY THIS EVENING...FROM NEAR 31N70W TO EASTERN CUBA BY EARLY TUE EVENING ...THEN LOSE ITS IDENTITY AS IT REACHES THE FAR ERN WATERS WED. WINDS AND SEAS DIMINISH OVER MUCH OF THE AREA S OF THE BAHAMAS THROUGH THIS EVENING...BUT STAY AT OR NEAR CURRENT LEVELS N OF THE BAHAMAS THROUGH TUE EVENING IN THE WAKE OF THE SECONDARY SURGE BEFORE DIMINISHING WED AND THU AS HIGH PRES BUILDS E ACROSS THE CENTRAL WATERS. THE PRES GRADIENT TIGHTENS OVER MUCH OF THE SRN WATERS LATE WED INTO FRI ALLOWING FOR NE-E WINDS OF 20 KT THERE AS THE HIGH SHIFTS TO THE FAR NE PORTION AND A FRONTAL SYSTEM APPROACHES THE E COAST OF THE U.S. CARIBBEAN SEA... THE PRELIMINARY 06 UTC ANALYSIS HAS THE ATLC COLD FRONT EXTENDING FROM ERN CUBA SW TO NRN COSTA RICA WITH A HIGH PRES RIDGE FROM THE GULF OF MEXICO BUILDING SEWD BEHIND IT. BUOY OBSERVATIONS FROM THROUGHOUT THE BASIN ARE REPORTING E TO SE WINDS OF 10-15 KT THROUGHOUT...EXCEPT W OF 80W WHERE NW-N WINDS OF 15-20 KT ARE IN PLACE PER BUOY AND A FEW SHIP OBSERVATIONS. SEAS ARE IN THE RANGES OF 2-4 FT E OF 75W...AND 5-7 FT W OF 75W EXCEPT TO 8 FT IN A NW SWELL IN THE FAR NW ZONE 011 AND YUCATAN CHANNEL. THE COLD FRONT IS FORECAST TO BEGIN TO WEAKEN AND SLOW DOWN AS IT REACHES FROM VICINITY WINDWARD PASSAGE TO CENTRAL COSTA RICA AS A CONTINUED WEAKENING FRONT EARLY THIS EVENING WHILE SLOWING DOWN. IT SHOULD THEN REACHES FROM NEAR WRN HAITI/WINDWARD PASSAGE TO NEAR 15N79W EARLY ON TUE...FROM HAITI AS WEAKENING STATIONARY FRONT SW TO 13N80W BY EARLY TUE EVENING...AND WEAKEN TO A REMNANT FRONTAL TROUGH FROM THE DOMINICAN REPUBLIC TO NEAR 14N78W BY EARLY ON WED. THE REMNANT TROUGH WILL THEN BEGIN TO MOVE BACK W TO THE VICINITY OF THE WINDWARD PASSAGE THU AND BE SOMEWHAT MORE DIFFUSE AS IT PASSES ACROSS ERN AND CENTRAL CUBA FRI. HOWEVER ...MOISTURE ASSOCIATED WITH IT IS EXPECTED TO MATERIALIZE INTO SCATTERED SHOWERS AND TSTMS WED THROUGH FRI. THE WINDS IN THE WRN PORTION OF THE CARIBBEAN BEHIND FRONT DIMINISH TO 10-15 KT TUE...EXCEPT IN THE SW PORTION WHERE A LINGERING TIGHT GRADIENT THERE WILL MAINTAIN N WINDS OF 20 KT TO ALONG THE COAST OF NICARAGUA AND NE HONDURAS INTO EARLY THU. THE DIMINISHED WINDS IN THE NW CARIBBEAN SEA WILL BE SHORT-LIVED AS THE PRES GRADIENT THERE IS DUE TO TIGHTEN AGAIN OVER THE NRN CARIBBEAN WATERS BEGINNING TUE AFTERNOON AND THROUGH FRI AS A RESULT OF HIGH PRES THAT BUILDS EWD AND INTERACTS WITH THE REMNANTS OF THE FRONT NEAR HISPANIOLA AND THE WINDWARD PASSAGE ...AND ALSO WITH GENERALLY LOWER PRES OVER THE CENTRAL AND SRN PORTIONS OF THE CARIBBEAN SEA. TROPICAL N ATLC S OF 19N W OF 55W... LIGHT NE-E WINDS PREVAIL THROUGHOUT...EXCEPT IN THE FAR SRN PORTION WHERE SLIGHTER STRONGER NE WINDS OF 15-20 KT WERE REVEALED IN THE PARTIAL 0022 UTC ASCAT PASS FROM LAST NIGHT. ALSO...SHIP "KAQP" JUST E OF THE ZONE AT 9N54W AND SHIP "WADN" AT 10N54W BOTH REPORTED E WINDS OF 20 KT WITHIN THE PAST HOUR. OBSERVED SEA STATE IS IN THE RANGE OF 4-5 FT...EXCEPT S OF ABOUT 13N WHERE HIGHER SEAS OF 5-7 FT ARE NOTED. THE FORECAST FOR THIS PART OF THE ATLC CALLS FOR LITTLE CHANGE DURING THE FORECAST PERIOD. IT IS POSSIBLE THAT THE DIFFUSE STAGE OF THE ATLC COLD FRONT MAY BRIEFLY ENTER THE FAR NW WATERS TUE NIGHT THROUGH WED BEFORE DAMPENING OUT AS IT SHIFTS BACK W THU AND FRI. WINDS ASSOCIATED WITH IT SHOULD BE ON THE LIGHT SIDE. THE TROUGH MAY BE ACCOMPANIED BY SCATTERED SHOWERS AND ISOLATED TSTMS. NOTE... EFFECTIVE APR 3, 2012 AT 1800 UTC THE OFFSHORE WATERS FORECAST ZONES CHANGED FOR THE CARIBBEAN AND SW N ATLANTIC AND THE GULF OF MEXICO. ISSUANCE TIME FOR THE GULF OF MEXICO OFFSHORE WATERS FORECASTS IS REFERENCED TO THE EASTERN TIME ZONE. FOR DETAILS SEE WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE). GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE