000 AGXX40 KNHC 240759 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 350 AM EDT TUE APR 24 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE DRY COLD FRONT THAT SWEPT SE ACROSS THE ERN AND MIDDLE OF THE AREA HAS NOW PUSHED FAR SE FROM THE LOWER STRAITS OF FLORIDA TO NRN YUCATAN PENINSULA. HIGH PRES OF 1020 MB IS CENTERED OVER THE FAR NW GULF AT 28N94W WITH A RIDGE SE TO NEAR 23N88W. BUOY OBSERVATIONS FROM ACROSS THE GULF SHOW NW 20 KT WINDS IN THE ERN PORTION E OF 86W...LIGHTER N WINDS OF 10-15 KT BETWEEN 86W AND 91W...AND EVEN LIGHTER WINDS OF 5-10 K W OF 91W N-NE IN DIRECTION EXCEPT SE-S 5-10 KT W OF 94W. AN ASCAT PASS FROM 0326 UTC LAST NIGHT REVEALED THE THE MIDDLE AND ERN GULF NW-N WINDS. THE BUOY OBSERVATIONS ARE REPORTING 6-8 FT SEAS IN THE ERN PORTION ...AND MUCH LOWER SEAS IN THE RANGE OF 4-5 FT IN THE MIDDLE PORTION...AND 2-4 FT IN THE WRN PART. THE FORECAST IS ON TRACK WITH THE NW 20 KT IN THE ERN GULF DIMINISHING TO 10-15 KT LATER THIS MORNING WITH SEAS THERE SUBSIDING TO 5-7 FT TONIGHT AND TO 2-4 FT WED. WINDS AND SEAS ELSEWHERE REMAIN ON THE LOW THROUGH LATE TONIGHT BEFORE SOME CHANGES IN SPEEDS AND SEAS BEGIN TO MATERIALIZE BEGINNING IN THE FAR WRN GULF TONIGHT. THE 1020 HIGH CENTER WILL MOVE E TO NEAR 27N86W BY LATE TONIGHT...AND TO CENTRAL WED. AS THIS HAPPENS...SE RETURN FLOW CONSISTING OF 20-25 KT WINDS 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 6-9 FT IN THE FAR WRN GULF WATERS WED NIGHT AND INTO SAT. BY THU...THE WRN EXTENSION OF ATLC HIGH PRES WILL EXTEND WWD ACROSS THE GULF ALONG 28N AND CONTINUE INTO SAT WITH THE TIGHTENING PRES GRADIENT IN THE WRN GULF ALLOWING FOR SE WINDS TO INCREASE TO 20 KT FROM W TO E TO ENCOMPASS THE WRN PORTION AND MOST OF THE MIDDLE PORTION AND FAR SRN WATERS OF THE ERN PORTION INCLUDING STRAITS OF FLORIDA WHERE E 20 KT WINDS ARE EXPECTED BY THEN. SW NORTH ATLC S OF 31N W OF 65W... THE PRELIMINARY 06 UTC SURFACE ANALYSIS HAS A COLD FRONT EXTENDING FROM 31N68W SW TO 26N73W WHERE IT BECOMES STATIONARY TO ERN CUBA. A PRE-FRONTAL TROUGH EXTENDS FROM 25N65W SW TO THE DOMINICAN REPUBLIC. A SECONDARY COLD FRONT...A DRY TYPE...IS RACING EWD OVER THE FAR WRN PORTION FROM THE NRN BAHAMAS TO WRN CUBA. A LINE OF SCATTERED SHOWERS IS NOTED WITHIN 30 NM OF THE FRONT. BOTH ASCAT DATA FROM LAST NIGHT ALONG WITH RECENT AND CURRENT BUOY OBSERVATIONS REVEAL THAT A TIGHT PRES GRADIENT CONTINUES IN PLACE PRIMARILY ACROSS THE NRN WATERS WHERE W-NW WINDS OF 20-25 KT ARE EVIDENT. LIGHTER NW-N WINDS OF 15 KT ARE ELSEWHERE OVER THE WRN PART OF THE AREA W OF THE FIRST FRONT...BUT HIGHER NW WINDS OF 20 KT ARE BEHIND THE SECOND FRONT. THE ASCAT PASS ALSO SHOWED SE WINDS OF 20-25 KT AHEAD OF THE FIRST FRONT N OF 26N...AND LIGHTER SE-S WINDS OF 10-15 KT S OF 26N E OF THE FRONT. LATEST BUOY OBSERVATIONS AND SEA STATE ANALYSIS FROM OPC SHOW SEAS IN THE RANGES OF 9-13 FT CONFINED TO N OF 29N BETWEEN 72W AND 78W...AND 6-9 FT ELSEWHERE N OF THE BAHAMAS. SEAS ARE LOWER S OF 27N E OF THE BAHAMAS WHERE BUOYS AND A FEW SHIPS RECENTLY REPORTED VALUES OF 2-4 FT...AND 5-6 FT SW OF THE BAHAMAS. NWP MODELS SUGGEST THAT THE FIRST COLD FRONT WILL CONTINUE TO SLOW ITS FORWARD PROGRESS AS IT APPROACHES A PSN FROM 31N63W TO 24N66W AND WEAKENING STATIONARY FROM THERE TO NW HAITI TONIGHT... THEN FROM NEAR 31N61W TO 24N64W AND WEAKENING STATIONARY TO 21N71W AND A FRONTAL TROUGH FROM THERE TO HAITI IN 48 HRS AT WHICH TIME THE SECOND FRONT WILL MERGE WITH IT. THE FRONT WILL BECOME STATIONARY AFTER 48 HRS WHILE SLOWLY DISSIPATING. THE FRONTAL TROUGH SEGMENT WILL THEN BEGIN TO TRACK BACK W WED NIGHT REACHING THE WATERS FROM SE BAHAMAS TO ERN CUBA THU AND BECOME DIFFUSE OVER CENTRAL CUBA FRI. WINDS DIMINISH TO W 10-15 KT IN THE FAR NRN WATERS THIS AFTERNOON AND TONIGHT...AND REMAIN NLY AT 10-15 KT ELSEWHERE EXCEPT SE-S 10-15 KT SE OF THE FRONT THROUGH MOST OF WED. A TROUGH WILL PASS JUST TO THE N OF THE FORECAST WATERS THIS AFTERNOON AND EVENING FOLLOWED BY INCREASING W-NW WINDS OF 20-25 KT. THIS SURGE OF WINDS BEHIND THE TROUGH WILL THEN QUICKLY SHIFT WELL TO THE NE WED NIGHT. HIGH PRES WILL E ACROSS THE CENTRAL WATERS WED THROUGH THU...THEN SHIFT N TO ALONG 29N LATE THU THROUGH SAT. THE PRES GRADIENT TIGHTENS OVER MUCH OF THE SRN PORTION WED INTO FRI AS THE FRONTAL TROUGH SEGMENT MOVES BACK W ALLOWING FOR NE-E WINDS OF 20 KT. BY SAT THE ENTIRE SRN WATERS PORTION WILL BE UNDER NE-E 20 KT WINDS. WINDS BECOME S-SW 10-15 KT IN THE FAR NRN PORTION THU THROUGH SAT WITH SW WINDS INCREASING TO 20 KT IN THE FAR NW PART FRI AND SAT. CARIBBEAN SEA... THE PRELIMINARY 06 UTC ANALYSIS HAS A TROUGH AHEAD OF THE ATLC COLD FRONT EXTENDING FROM THE DOMINICAN REPUBLIC SW TO NEAR 13N76W. THE ATLC SECOND COLD FRONT IS MOVING QUICKLY S THROUGH THE YUCATAN CHANNEL. BUOY OBSERVATIONS ACROSS THE BASIN ARE REPORTING E TO SE WINDS OF 10-15 KT THROUGHOUT...EXCEPT W OF 78W WHERE NW-N WINDS OF 10-15 KT ARE NOTED AND N WINDS OF 20 KT S OF 17N W OF 80W. SEAS ARE IN THE RANGES OF 3-5 FT BETWEEN 65W-74W...AND 2-4 FT ELSEWHERE E OF 78W. SEAS ARE 4-6 FT W OF 78W...EXCEPT 6-7 FT S OF 15N BETWEEN 74W-82W. THE COLD FRONT MOVING ACROSS THE YUCATAN CHANNEL WILL DISSIPATE AS IT REACHES FROM CENTRAL CUBA TO NEAR 20N85W LATER THIS MORNING. THE TROUGH FROM THE DOMINICAN REPUBLIC TO NEAR 13N76W WILL CONTINUE INTO WED BEFORE IT BEGINS TO MOVE BACK W TO THE VICINITY OF THE WINDWARD PASSAGE THU...THEN BECOMES DIFFUSE AS IT REACHES CENTRAL CUBA FRI. ASSOCIATED SCATTERED SHOWERS AND TSTMS WED WILL CONTINUE TO AFFECT HE N CENTRAL WATERS THROUGH THU. THE N WINDS OF 20 KT S OF 17N W OF 80W WILL CONTINUE THROUGH LATE THU...THEN BECOME NE-E 15-20 KT FRI AND SAT. ELSEWHERE...A TIGHTENING PRES GRADIENT WILL INDUCE NE-E 20 KT OVER A GOOD PORTION OF THE BASIN FROM WED AFTERNOON THROUGH SAT AS ATLC HIGH PRES BUILDS EWD AND INTERACTS WITH THE REMNANT FRONTAL TROUGH. NE WINDS OF 20-25 KT CAN BE EXPECTED THROUGH AND NEAR THE WINDWARD PASSAGE DURING THIS PERIOD. 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 CONTINUE. SEAS IN THIS PART OF THE ATLC ARE IN THE RANGE OF 4-5 FT. LITTLE CHANGE IN CONDITIONS ARE EXPECTED THROUGH MOST OF THU. THE ONLY FORESEEABLE CHANGE IS INCREASING NE-E WINDS OF 15-20 KT IN THE CENTRAL PORTION LATE THU THROUGH SAT. THE ATLC PRE-FRONTAL TROUGH IS FORECAST BY THE MODELS TO ENCROACH INTO THE NW PORTION THIS PART OF THE ATLC WED THROUGH LATE THU BEFORE IT SHIFTS BACK TO THE W ON FRI. WINDS ASSOCIATED WITH IT SHOULD BE ON THE LIGHT SIDE. THE TROUGH MAY BE ATTENDANT 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