000 AGXX40 KNHC 031834 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 234 PM EDT SUN MAY 3 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: 12 UTC GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. 12 UTC TAFB NWPS FOR WAVE PARAMETERS. HIGH CONFIDENCE. WEAK 1018 MB HIGH PRES IS LOCATED IN THE CENTRAL LOUISIANA COASTAL WATERS NEAR 29N91W...WITH LIGHT TO MODERATE WINDS AND 1 TO 3 FT SEAS PREVAILING ACROSS THE GULF WATERS W OF 90W. A SURFACE TROUGH HAS DEVELOPED IN THE FAR EASTERN GULF EXTENDING FROM THE WESTERN FLORIDA PANHANDLE SOUTHWARD TO THE SE GULF NEAR 24N85W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ACCOMPANYING THE TROUGH AS IT IS MOVING W AROUND 5 TO 10 KT. OTHERWISE A BROAD UPPER TROUGH IS MAINTAINING FAIRLY BENIGN WEATHER WITH DRY AIR AND SUBSIDENCE IN PLACE E OF 94W. THE PATTERN WILL BECOME MORE AMPLIFIED OVER THE NEXT SEVERAL DAYS AS AN UPPER IMPULSE MOVES FROM THE SOUTHERN PLAINS INTO BASE OF THE UPPER TROUGH. GLOBAL MODELS INDICATE TROPICAL MOISTURE SHIFTING NORTHWARD AHEAD OF THIS IMPULSE INTO THE SE GULF... ALLOWING FOR INCREASE SHOWERS AND THUNDERSTORM ACTIVITY OVER THE SE GULF MON INTO TUE. THE AMPLIFYING PATTERN WILL ALSO ALLOW THE SUBTROPICAL RIDGE OFF THE CAROLINA COAST TO BUILD. THE RESULTING INCREASED PRES GRADIENT WILL ALLOW FOR FRESH TO OCCASIONAL STRONG EASTERLY FLOW THROUGH THE STRAITS OF FLORIDA THIS AFTERNOON INTO MON NIGHT. THE FETCH AND DURATION OF THE E FLOW AGAINST THE FLORIDA CURRENT WILL RESULT IN SEAS BUILDING TO 8 FT OVER THE SE GULF OFF THE NW COAST OF CUBA ON MON. THE GRADIENT RELAXES BY TUE AS THE HIGH SHIFTS EAST AND TROUGHING TO THE SOUTH DAMPENS OUT... LEAVING GENERALLY MODERATE SE FLOW ACROSS MOST THE BASIN THROUGH FRI...EXCEPT WINDS MORE NE-E IN THE GULF E OF 87W...WITH SEAS SUBSIDING TO 3 TO 5 FT ACROSS THE SW HALF OF THE GULF AND 1 TO 3 FT IN THE NE HALF OF THE GULF FOR THE END OF THE WEEK. NE TO E WINDS WILL INCREASE TO 15 TO 20 KT ALONG AND JUST OFFSHORE OF THE NW PORTION OF THE YUCATAN PENINSULA DURING THE EVENING THROUGH EARLY MORNING HOURS EACH DAY THROUGH THE END OF THE WEEK. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12 UTC GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. 12 UTC TAFB NWPS FOR WAVE PARAMETERS. HIGH CONFIDENCE. A PESKY STATIONARY FRONT IS DISSIPATING FROM EASTERN CUBA TO EASTERN HONDURAS WITH SHOWERS AND TSTMS IN THE VICINITY OF THE DECAYING BOUNDARY. THIS FRONT WILL FINALLY DISSIPATE LATER TODAY BECOMING A REMNANT TROUGH BY MON MORNING. THIS SURFACE TROUGH WILL BE SUPPORTED BY AN APPROACHING UPPER TROUGH OVER THE NW CARIBBEAN AFTER THE FRONT WASHES OUT. MEANWHILE FARTHER EAST THE SUBTROPICAL RIDGE IS SHIFTED A LITTLE MORE SOUTHEASTWARD DUE TO A SERIES OF STRONG UPPER IMPULSES NORTH OF THE AREA. HIGH PRES WILL BUILD OVER THE EASTERN UNITED STATES AND MODELS REMAIN IN GOOD AGREEMENT SHOWING THAT THIS WILL INCREASE TRADE WINDS ACROSS THE CENTRAL CARIBBEAN TO INCLUDE THE EASTERN COAST OF COLOMBIA THROUGH THE WEEK. ASSOCIATED WAVE HEIGHTS BUILD TO 8 TO 11 FT TUE...THEN UP TO 12 FT WED THROUGH FRI. MODERATE TO FRESH TRADES WILL PERSIST OVER THE TROPICAL N ATLC WITH SEAS 5 TO 8 FT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12 UTC ECMWF BLENDED WITH PREVIOUS/OFFICIAL FORECAST. 12 UTC TAFB NWPS FOR SEAS. HIGH CONFIDENCE THROUGH MON...THEN MEDIUM CONFIDENCE THEREAFTER MOST PARTICULARLY WITH THE POSSIBLE FORMATION OF LOW PRES IN VICINITY OF BAHAMAS. A WEAKENING COLD FRONT EXTENDS FROM 31N57W TO 24N67W WHERE IT BECOMES STATIONARY BEFORE CONTINUING TO EASTERN CUBA. 1022 MB HIGH PRES HAS SHIFTED OFF OF THE SE UNITED STATES COAST TO NEAR 31N80W IN THE WAKE OF THE FRONT. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING NEAR THE FRONTAL BOUNDARY AND A RECENT ASCAT PASS MEASURED FRESH TO STRONG NE-E WINDS S OF 25N W OF 73W. OTHERWISE MODERATE TO LOCALLY FRESH ANTICYCLONIC WINDS ARE IN PLACE ACROSS THE BASIN. SEAS ARE 7-11 FT IN NORTHERLY SWELL N OF 27N WHICH IS 2-3 FT ABOVE THE LATEST WAVEWATCH MODEL GUIDANCE... WITH 4-7 FT SEAS S OF 27N EXCEPT 1-3 FT IN THE PROTECTED WATERS OF THE BAHAMAS. THE HIGHER SEAS WILL SUBSIDE TO LESS THAN 8 FT BY LATE TONIGHT. THE SOUTHERN/STATIONARY PORTION OF THE FRONT WILL BECOME DIFFUSE THROUGH MON. THE FORECAST ISSUE FOR TUE THROUGH FRI CONTINUES TO BE THE POSSIBLE DEVELOPMENT OF LOW PRES OVER THE NORTHERN BAHAMAS. SOME DISAGREEMENT PERSISTS IN MODEL OUTPUT REGARDING THE TIMING... POSITION AND STRENGTH OF THE LOW PRES. THE GFS APPEARS TO CONTINUE TO SUFFER FROM SOME CONVECTIVE FEEDBACK ISSUES WHICH IS LEADING TO A STRONGER SOLUTION...AND ALSO MUCH CLOSER TO THE SE UNITED STATES COAST COMPARED TO THE LATEST ECMWF AND UKMET SOLUTIONS WITH THE NEW 12 UTC ECMWF TRENDING EASTWARD CLOSER TO THE UKMET SOLUTION. THE UKMET AND ECMWF ARE ALSO CONSIDERABLY MORE WEAK WITH THE WINDS ASSOCIATED WITH THE LOW. NEEDLESS TO SAY MUCH UNCERTAINTY REMAINS WITH THIS LOW AND THE FORECAST WILL CONTINUE TO FOLLOW THE MORE CONSERVATIVE ECMWF SOLUTION. ELSEWHERE MODERATE SE FLOW PERSIST ACROSS THE REGION IN THE WAKE OF THE TROUGH/LOW. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 LEWITSKY. NATIONAL HURRICANE CENTER.