000 AGXX40 KNHC 300623 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 223 AM 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. ...GULF OF MEXICO... MODEL PREFERENCE: 12Z ECMWF PREFERRED FOR WINDS. BLEND OF TAFB NWPS AND 12Z EC WAVE FOR WAVES. MEDIUM CONFIDENCE. THE 0300Z ASCAT-B PASS SHOWS 20-25 KT N WINDS S OF 22N IN THE SW GULF. THE STRONGER 12Z ECMWF SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT CONDITIONS THAN THE 00Z GFS. THEIR SURFACE WIND FORECASTS ARE VERY SIMILAR THROUGH SAT AS HIGH PRES DEVELOPS IN THE NW GULF THEN TRACKS E ALONG THE N GULF COASTAL PLAIN...BUT DIFFERENCES ALOFT BEGIN TO ARISE BY SAT NIGHT. THE 00Z GFS CARRIES A STRONGER SYSTEM FROM N CENTRAL MEXICO TODAY INTO THE NW GULF LATE FRI AND IS FASTER TO CARRY IT ACROSS FLORIDA SAT THAN THE 12Z ECMWF AND THE GEFS AND EC ENS MEANS. THESE MODEL BOTH SHOW WINDS PICKING UP TO A FRESH BREEZE IN THE E GULF BY 06Z SUN...WITH THE GFS FOCUSED OFF SARASOTA AND THE ECMWF FARTHER S IN THE STRAITS OF FLORIDA. THE GFS GOES ON TO EXPAND THAT AREA OF FRESH TO STRONG WINDS ACROSS ZONE GMZ015. THE OTHER MODELS ARE WEAKER HERE. ALOFT...THE MODEL AGREE ON MOVING THE BULK OF THE ENERGY IN THIS TROUGH QUICKLY INTO THE ATLC...BUT LEAVE SOME BEHIND AS RIDGING BUILDS ACROSS THE S CENTRAL ATLC. THIS ALLOWS FOR A DEEP LAYERED LOW TO DEVELOP INVOF THE NORTHERN BAHAMAS BY TUE NIGHT BEYOND THE FORECAST PERIOD. THE GFS CONTINUES TO BE ON THE STRONG SIDE OF THE GUIDANCE WITH THIS SYSTEM. THE 12Z ECMWF WAS USED FOR THE WIND FORECAST. THE EC WAVE WAS BLENDED WITH THE HEAVILY WEIGHTED NWPS FOR SEAS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z ECMWF PREFERRED FOR WINDS. BLEND OF TAFB NWPS AND 12Z EC WAVE FOR WAVES. MEDIUM CONFIDENCE. SATELLITE IMAGERY SHOWS SMOKE STILL LINGERS PRIMARILY S OF 20N W OF 84W DUE TO AGRICULTURAL FIRES OVER HONDURAS. A PRE-FRONTAL TROUGH FROM 17N87W TO THE WESTERN TIP OF CUBA IS FOCUSING THE SMOKE TO ITS E. THE COLD FRONT OVER THE SOUTHERN GULF OF MEXICO WILL MOVE INTO THE AREA TODAY AND USHER IN SOME N WINDS OVER MUCH OF THIS REGION WHICH SHOULD HELP KEEP THE SMOKE OVERLAND. BOTH THE GFS AND 12Z ECMWF AGREE ON WASHING OUT THE COLD FRONT IN THE NW GULF ON SUN. THE PRESSURE GRADIENT HAS BUILT OVER THE SE CARIB BETWEEN THE SUBTROPICAL RIDGE AND LOWER PRES IN THE WESTERN CARIB ASSOCIATED WITH THE APPROACHING COLD FRONT. AN AREA OF FRESH TO STRONG TRADES IS EXPECTED TO PERSIST THROUGH FRI MORNING PRIMARILY OFF THE N CENTRAL AND NW COAST OF VENEZUELA. WINDS SHOULD DIMINISH LATE FRI AS THE SUBTROPICAL RIDGE IS FORCED E BY THE COLD FRONT IN THE SW N ATLC...WITH FRESH TO STRONG TRADES RETURNING ALONG THE COAST OF COLOMBIA IN THE OVERNIGHT/EARLY MORNING HOURS DURING THE WEEKEND AND ALONG THE S CENTRAL CARIB SUN NIGHT AS HIGH PRES BUILDS BEHIND THE FRONT IN THE SW N ATLC AND THEN IN THE CENTRAL ATLC AND THE FRONT TO THE N WEAKENS. USED THE ECMWF FOR WINDS AS IT IS PREFERRED FOR THE DRIVING PATTERN TO THE N AND THE EC WAVE WAS BLENDED WITH THE TAFB NWPS FOR SEAS...RELYING HEAVILY ON THE NWPS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z ECMWF PREFERRED FOR WINDS. BLEND OF TAFB NWPS AND 12Z EC WAVE FOR WAVES. MEDIUM CONFIDENCE. THE GENERAL TREND IN THE MODELS THE LAST FEW DAYS HAS BEEN TOWARD LESS DEVELOPMENT OF THE LOW IN THE GULF OF MEXICO AND A MORE SLY TRACK AS IT MOVES INTO THE ATLC TODAY. THE 18Z GFS HAD BEEN ON THE STRONGER AND MORE NLY EDGE OF THE GUIDANCE...BUT THE 00Z RUN HAS ADJUSTED TOWARD THE CONSENSUS AND THE ECMWF. THE PREVIOUS FORECAST RELIED TOO HEAVILY ON OLDER...MORE WRAPPED UP SOLUTIONS...SO IT WAS LARGELY SCRAPPED FOR THE LATEST ECMWF SOLUTION HERE WHICH IS NOT FAR FROM THE GFS. THE EC WAVE MODEL IS CLOSER TO THE SEAS SEEN BY THE 0256Z ALTIMETER PASS ALONG 67W THAN THE MW3 WHICH IS 2-3 FT TOO LOW. THE EC WAVE WAS RELIED ON MORE HEAVILY EARLY IN THE PERIOD WITH THE NWPS RELIED ON MORE BY FRI NIGHT AS THE SYSTEM MOVES AWAY. THE 12Z ECMWF IS ALSO PREFERRED WITH THE UPPER TROUGH MOVING INTO THE GULF OF MEXICO...WHICH APPEARS TO BE TOO AMPLIFIED IN GFS. DETAILS WITH THIS SYSTEM ARE DISCUSSED IN THE GULF OF MEXICO SECTION. BEYOND THE FORECAST PERIOD...THE 00Z GFS CONTINUES TO BE ON THE STRONG SIDE OF THE GUIDANCE WITH THE DEEP LAYERED LOW EXPECTED TO DEVELOP INVOF THE NORTHERN BAHAMAS BY TUE NIGHT BEYOND THE FORECAST PERIOD. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 SCHAUER. NATIONAL HURRICANE CENTER.