000 AGXX40 KNHC 301851 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 251 PM EDT THU APR 30 2015 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. MODEL PREFERENCE: 00 UTC ECMWF BLENDED WITH PREVIOUS OFFICIAL. USED BLEND OF TAFB NWPS AND 00 UTC ECMWF FOR WAVES. HIGH CONFIDENCE THROUGH SAT...THEN MEDIUM CONFIDENCE THEREAFTER. A COLD FRONT IS PUSHING AWAY FROM THE SE GULF AS IT IS NOW PRESENTLY ANALYZED FROM THE UPPER STRAITS OF FLORIDA SW TO NW CUBA...AND TO INLAND THE YUCATAN PENINSULA JUST S OF CANCUN. A POST-FRONTAL TROUGH EXTENDS FROM TAMPA BAY WSW TO 26N93W. WEAK TO MODEST HIGH PRES IS BUILDING EASTWARD ACROSS THE GULF IN THE WAKE OF THE FRONT AND TROUGH. LATEST SATELLITE BUOY...CMAN AND A FEW SHIP REPORTS ARE REVEALING GENERALLY GENTLE TO MODERATE N WINDS OVER THE AREA...EXCEPT FOR LIGHT AND VARIABLE 5-10 KT WINDS IN THE FAR NW PORTION. LATEST ALTIMETER DATA ALONG WITH BUOY AND FEW SHIP REPORTS ARE SHOWING SEAS IN THE 4-6 FT RANGE...EXCEPT HIGHER SEAS OF 6-7 FT IN THE SW GULF. LOWER SEAS OF 1-2 FT ARE SEEN IN THE FAR NW GULF WHERE THE LIGHT AND VARIABLE ARE PRESENT. THE 6-7 FT SEAS ARE FORECAST TO SUBSIDE TO 4-5 FT TONIGHT...AND TO 2-3 FT FRI. THE SMOKE AND HAZE FROM THE PREVIOUS SEVERAL DAYS NOTED OVER THE BAY OF CAMPECHE HAS SHIFTED EASTWARD TO THE FAR WESTERN CARIBBEAN PRIMARILY IN THE GULF OF HONDURAS ZONE 17. THE FORECAST CALLS FOR THE POST-FRONTAL TROUGH TO MOVE E OF THE GULF TONIGHT...AND FOR HIGH PRES TO CONTINUE TO SHIFT EASTWARD THROUGH SAT...THEN BECOME REINFORCED BY STRONGER HIGH PRES THAT BUILDS SSW ALONG THE SE U.S. COAST AND OVER THE MUCH OF THE CENTRAL AND EASTERN GULF ZONES SUN THROUGH LATE TUE. LONG TERM CHANGES TO THE FORECAST WILL BE SEEN AS AN INCREASE OF ELY WINDS OVER THE SE GULF AND SUN AND SUN NIGHT...AND THEN THE REST OF THE EASTERN GULF AS WELL AS THE EASTERN PART OF THE CENTRAL GULF MON THROUGH TUE NIGHT AS THE GRADIENT TIGHTENS BETWEEN THE HIGH PRES AND A TROUGH THAT MOVES WESTWARD ACROSS THE EASTERN GULF. SEAS ARE EXPECTED TO BUILD THERE TO THE RANGE OF ABOUT 6-8 FT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: EVEN BLEND OF THE 00 ECMWF WITH PREVIOUS OFFICIAL. USED BLEND OF TAFB NWPS WITH PREVIOUS FOR SEAS. HIGH CONFIDENCE. A COLD FRONT ENTERED THE FAR NW CARIBBEAN THIS MORNING...AND AS 18 UTC IS ANALYZED FROM NW CUBA SW TO INLAND THE BELIZE/YUCATAN PENINSULA BORDER. A WEAK 1008 MB LOW IS LOCATED NEAR 18N85W WITH A TROUGH EXTENDING NEWD TO 22N81W...AND SW TO THE COAST OF N CENTRAL HONDURAS. THE 1436 UTC HIGH RESOLUTION ASCAT PASS REVEALED QUITE AN IMPRESSIVE SWATH OF SE FRESH WINDS OVER THE EASTERN CARIBBEAN BETWEEN 64W AND 70W. AN ALTIMETER PASS FROM EARLIER TODAY SHOWED SEAS OF 9-10 FT ALONG THE W SIDE OF THIS SWATH. ELSEWHERE... LATEST SATELLITE DERIVED WINDS AND ALTIMETER DATA ALONG WITH BUOY REPORTS AND FEW SHIP OBSERVATIONS SHOW GENTLE TO MODERATE E-SE WINDS W OF 70W...WITH THE EXCEPTION OF FRESH N WINDS BEHIND THE FRONT. MODERATE E WINDS ARE OVER THE TROPICAL ATLC AS NOTED IN THE 1256 UTC PASS AND IN REPORTS BY BUOYS 41300 AND 41040. SEAS ELSEWHERE ARE IN THE 4-6 FT RANGE...EXCEPT FOR 5-6 FT BEHIND THE FRONT...AND LOWER SEAS OF 2-3 FT OVER THE NE PART OF THE CARIBBEAN. THE SMOKE FROM AGRICULTURAL FIRES OF THE PREVIOUS APPEARS TO CONFINED OVER THE AND NEAR THE GULF OF HONDURAS EARLY THIS AFTERNOON...ALTHOUGH IT DOES LOOK AS DENSE AS IN PREVIOUS DAYS AS MOISTURE AND CLOUDS CONTINUE TO MIXED WITH IT. THE SMOKE SHOULD THIN OUT TONIGHT INTO FRI AS THE FRONT ADVANCES EASTWARD. THE COLD FRONT WILL BE FORECAST TO REACH FROM CENTRAL CUBA TO NE EARLY ON FRI...THEN BECOME STATIOANRY AND GRADUALLY DISSIPATE THROUGH FRI NIGHT. THE LOW AND TROUGH ARE FORECAST TO LOSE THEIR IDENTITY AS THE FRONT MOVES INTO THAT AREA DURING FRI. THE FRESH NORTHERLY WINDS BEHIND THE FRONT WILL DIMINISH TO MODERATE LATE TONIGHT INTO FRI. THE SE FRESH WINDS OVER THE EASTERN CARIBBEAN SEA WILL BRIEFLY DIMINISH SAT...THEN COME BACK TO FRESH SPEEDS SUN...AND EXPAND IN AREAL COVERAGE MON AND TUE AS STRONG HIGH PRES BUILDS SEWD ACROSS THE CENTRAL ATLC. ASSOCIATED SEAS ARE FORECAST TO BUILD TO 8-10 FT MON AND TO 9-12 FT TUE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: EVEN BLEND OF THE 00 ECMWF WITH PREVIOUS OFFICIAL. USED BLEND OF TAFB NWPS WITH PREVIOUS FOR SEAS. HIGH MEDIUM CONFIDENCE THROUGH SAT...THEN HIGH CONFIDENCE THEREAFTER. THE 18 UTC SURFACE ANALYSIS HAS A COLD FRONT EXTENDING FROM A 1003 MB LOW PRES NEAR 33N76W. A COLD FRONT EXTENDS FROM THE LOW SW TO 27N76W TO NW CUBA. LATEST SATELLITE DERIVED WINDS AND SEAS ALONG WITH SHIP...BUOY...AND CMAN DATA DEPICT MODERATE TO FRESH SW WINDS OVER THE FAR NE WATERS...AND FRESH NW WINDS BEHIND THE COLD FRONT. MODERATE SLY WINDS NOTED ELSEWHERE ACROSS THE BASIN. SEAS ARE IN THE 6-8 FT RANGE OVER THE FAR NE WATERS...5-6 FT OVER THE REMAINDER OF THE AREA EXCEPT FOR LOWER VALUES OF 1-2 FT IN THE BAHAMA ISLAND CHAIN WATERS AND 4-5 FT W OF 79W. THE FORECAST HAS CHANGED VERY LITTLE WITH RESPECT TO THE FORECAST POSITIONS OF THE COLD FRONT. THE COLD FRONT WILL REACH FROM NEAR 31N77W TO CENTRAL CUBA TONIGHT...FROM NEAR 31N68W TO CENTRAL CUBA EARLY ON FRI...THEN BEGIN TO SLOW DOWN AS IT REACHES FROM 31N67W TO CENTRAL CUBA BY LATE FRI NIGHT. A SECOND COLD FRONT WILL QUICKLY MERGE WITH THE FIRST FRONT EARLY ON SAT FROM NEAR 29N65W TO CENTRAL CUBA...REACH FROM NEAR 27N65W TO EASTERN CUBA BY EARLY SAT EVENING...THEN BECOME STATIONARY AND WEAKEN FROM 26N65W TO 23N70W AND TROUGH TO EASTERN CUBA SUN. THE STATIONARY PORTION WILL DISSIPATE MON WHILE THE REMNANT TROUGH MOVES WESTWARD ACROSS THE FAR SOUTHERN WATERS. THE TROUGH IS EXPECTED TO REACH THE VICINITY OF THE CENTRAL BAHAMAS AND CENTRAL CUBA BY LATE MON AS STRONG HIGH PRES BUILDS SE N AND NE OF THE BAHAMAS. GLOBAL MODELS SUGGEST THAT THE TROUGH WILL EXPAND SOME NORTHWARD AND STALL E OF FLORIDA FROM NEAR THE NW BAHAMAS SW TO NEAR N CENTRAL CUBA BY TUE WITH A TIGHT PRES GRADIENT TO ITS N AND NE SUPPORTING W WINDS OF ABOUT THE 20-25 KT RANGE WITH SEAS OF AROUND 8 FT. THE FORECAST FOR WINDS AND AND SEAS WITH THIS TROUGH WILL BE SUBJECT TO CHANGES BASED ON FUTURE MODELS TRENDS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.