000 AGXX40 KNHC 021809 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 209 PM EDT SAT MAY 2 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 VALUES FOR WAVE PARAMETERS. HIGH CONFIDENCE. A WEAK COLD FRONT CONTINUES TO DRIFT SOUTHWARD OVER THE EASTERN GULF CURRENTLY PUSHING THROUGH THE FLORIDA KEYS INTO THE STRAITS OF FLORIDA. LATEST BUOY AND LAND BASED OBSERVATIONS INDICATE THAT THE AIRMASS BEHIND THE FRONT IS MODIFYING AND THE FRONT WILL LIKELY WASH OUT THROUGH THE REST OF TODAY. 1019 MB HIGH PRES IS ANALYZED OVER THE NW GULF NEAR 28N93W WHICH WILL BECOME ABSORBED INTO A LARGER HIGH PRES AREA CENTERED OVER CENTRAL TENNESSEE. THIS WILL LEAVE A WEAK PRES PATTERN ACROSS THE GULF FOR THE REMAINDER OF TODAY INTO TONIGHT. THE HIGH PRES WILL BUILD AS IT SHIFT EASTWARD TONIGHT TOWARD THE CAROLINAS. THIS WILL BE IN PHASE WITH A WEAK SURFACE TROUGH EXTENDING FROM THE NW CARIBBEAN THROUGH WESTERN CUBA INTO THE FAR SE GULF. THE RESULTING TIGHT PRES GRADIENT WILL SUPPORT FRESH TO OCCASIONALLY STRONG E FLOW THROUGH THE STRAITS OF FLORIDA SUN AFTERNOON THROUGH LATE MON. 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 MONDAY. 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 THU WITH SEAS SUBSIDING TO 3-5 FT ACROSS THE SW HALF OF THE GULF AND 1-3 FT IN THE NE HALF. WINDS WILL INCREASE TO 20 KT OVER THE NW GULF BY WED AHEAD OF LOW PRES FORMING OVER THE SOUTHERN PLAINS. WINDS WILL ALSO PULSE TO 20 KT ALONG AND OFFSHORE OF THE NW PORTION OF THE YUCATAN PENINSULA DURING THE OVERNIGHT HOURS THROUGH THE FORECAST PERIOD. ...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 VALUES FOR WAVE PARAMETERS. HIGH CONFIDENCE. A STATIONARY FRONT REACHES FROM EASTERN CUBA TO NE HONDURAS THIS MORNING AS CAPTURED NICELY BY A RECENT ASCAT-B SCATTEROMETER PASS. THE FRONT IS FORECAST TO BECOME DIFFUSE THROUGH SUN PRIOR TO BECOMING A REMNANT SURFACE 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. THIS HAS BEEN KEEPING FRESH TO STRONG TRADE WINDS OFF THE EASTERN VENEZUELA COAST FOR THE PAST FEW DAYS. THIS PATTERN HAS STARTED TO TRANSITION IN RESPONSE TO STRONGER HIGH PRES CENTERED OVER THE EASTERN UNITED STATES. MODELS REMAIN IN GOOD AGREEMENT SHOWING THAT THIS WILL INCREASE TRADE WINDS AND DISPLACE THE MAIN AREA OF FRESH TO STRONG TRADES TO THE CENTRAL CARIBBEAN TO INCLUDE THE EASTERN COAST OF COLOMBIA THROUGH WED. ASSOCIATED WAVE HEIGHTS BUILD 8 TO 11 FT TUE...THEN UP TO 12 FT WED AND THU. MODERATE TO FRESH TRADES WILL PERSIST OVER THE TROPICAL N ATLC WITH SEAS 5 TO 7 FT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z ECMWF BLENDED WITH PREVIOUS OFFICIAL. USED BLEND OF TAFB NWPS WITH PREVIOUS FOR SEAS. HIGH CONFIDENCE THROUGH MON...THEN MEDIUM CONFIDENCE THEREAFTER MOST PARTICULARLY WITH THE POSSIBLE FORMATION OF LOW PRES IN VICINITY OF BAHAMAS. A WEAK COLD FRONT REACHES FROM 31N67W TO THE FLORIDA KEYS. THIS FRONT WILL WEAKEN AS IT DRIFTS SE THROUGH LATER TODAY...EVENTUALLY MERGING WITH A STATIONARY FRONT WHICH IS CURRENTLY REACHING FROM 28N65W TO EASTERN CUBA. THE MERGED FRONT WILL THEN SHIFT SE BEFORE BECOMING DIFFUSE N OF HISPANIOLA AND PUERTO RICO ON SUN. BUOY OBSERVATIONS JUST N OF 31N INDICATE FRESH TO STRONG WINDS IN THE WAKE OF THE FRONT ALONG WITH 10 TO 12 FT SEAS WITH OUTER 8 TO 9 FT SEAS PROPAGATING INTO THE SW N ATLC N OF 30N BETWEEN 72W AND 78W. WINDS WILL DIMINISH TO 20 KT OR LESS LATER TODAY INTO TONIGHT WITH THE FRONT WEAKENING AS THE MAIN UPPER DYNAMICS LIFT OUT OF THE AREA...BUT LINGERING NORTHERLY SWELL OF 8 TO 9 FT WILL PREVAIL ACROSS THE WATERS N OF 29N BETWEEN 64W AND 75W THROUGH SUN MORNING BEFORE SUBSIDING SUN NIGHT. HIGH PRES WILL BUILD OVER THE CAROLINAS SUNDAY AND MONDAY...MAINTAINING GENERALLY MODERATE TRADES OVER THE REGION EXCEPT FOR BRIEF PULSES OF STRONGER WINDS THROUGH THE SOUTHERN BAHAMAS AND OFF HISPANIOLA LATE SUN AND LATE MON. THE FORECAST ISSUE FOR TUE THROUGH THU CONTINUES TO BE THE POSSIBLE DEVELOPMENT OF LOW PRES OVER THE NORTHERN BAHAMAS. SOME SIGNIFICANT DISAGREEMENT CONTINUES 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 MUCH STRONGER SOLUTION...MOVING N OF THE AREA BY THU MORNING BEFORE DRIFTING BACK SW-S INTO THE AREA. THERE ALSO HAS BEEN LITTLE RUN TO RUN CONSISTENCY WITH THE GFS WITH REGARD TO THE LOW. THE ECMWF SHOWS A MUCH WEAKER LOW LOCATED MORE TO THE SW CLOSER TO THE NORTHERN BAHAMAS BY WED MORNING...LIFTING N OF THE AREA BY LATE THU NIGHT. MEANWHILE THE UKMET MODEL IS SLOWER WITH THE DEVELOPMENT OF THE LOW AND LOCATES IT MORE TO THE NE FARTHER AWAY FROM THE NORTHERN BAHAMAS. NEEDLESS TO SAY MUCH UNCERTAINTY REMAINS WITH THIS LOW AND THE FORECAST WILL CONTINUE TO FOLLOW THE MORE CONSERVATIVE ECMWF SOLUTION WHICH WAS COORDINATED WITH NEIGHBORING WEATHER FORECAST OFFICES. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.