000 AGXX40 KNHC 211858 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 258 PM EDT SAT MAR 21 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: 00Z ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE PARAMETERS. MEDIUM-LOW CONFIDENCE. THE 00Z ECMWF AND 12Z GFS CONTINUE TO DIVERGE WITH THE STRENGTH OF THE LOW PRES SYSTEM MOVING FROM TEXAS EASTWARD THROUGH THE SOUTHERN PORTION OF THE GULF COASTAL STATES INTO NORTHERN FLORIDA SAT THROUGH MON. THE GFS IS FASTER AND WEAKER THAN THE 00Z ECMWF WITH THE LOW AND COLD FRONT. THE 00Z ECMWF MORE CLOSELY RESEMBLES THE OTHER 12Z MODELS. THE GEFS AND EC ENS MEANS SUPPORT THE OPERATIONAL RUNS. CONFIDENCE IS LOWER THAN AVERAGE. A BLEND OF THE PREVIOUS FORECAST AND THE ECMWF WAS USED FOR THE FORECAST. FOR WAVES...THE TAFB NWPS WAS USED FOR WINDS. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW THE ADVISORY CRITERIA OF 20-25 KT AND 8 FT...RESPECTIVELY...THROUGH THE END OF THE FORECAST PERIOD WED NIGHT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS AND 00Z ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST PLUS NWPS. THE TRPCL N ATLC WAS BLENDED WITH THE 00Z EUROPEAN PLUS THE PREVIOUS OFFICIAL PLUS THE EUROPEAN WAVE. MEDIUM CONFIDENCE. WEAK ATLC RIDGING N OF THE AREA COMBINED WITH LOW PRES IN NW COLOMBIA WILL SUPPORT PULSES OF 20-25 KT NE WINDS WITHIN 90 NM OF THE COAST OF COLOMBIA EACH NIGHT THROUGH TUE NIGHT...DIMINISHING TO 15-20 KT BY LATE MORNING. ON WED NIGHT...THE MODELS AGREE ON BUILDING HIGH PRES ACROSS THE SW N ATLC...ALLOWING A FRESH TO STRONG BREEZE TO EXPAND INTO A LARGER AREA OFF THE COAST OF COLOMBIA. THE 12Z GFS WAS USED TO POPULATE THIS AREA AS IT HAS THE HIGHEST RESOLUTION AND GENERALLY DOES BEST IN THIS AREA. THE 14Z SCATTEROMETER PASS SHOWED WINDS OFF THE COAST OF COLOMBIA IN THE 20 KT RANGE. THE 15Z SCATTEROMETER PASS SHOWED 15 KT EASTERLY WINDS IN THE GULF OF HONDURAS...BETWEEN A WEAKENING RIDGE ACROSS THE SOUTHERN BAHAMAS AND LOWER PRESSURE THAT IS TO THE SW OF THE GULF OF TEHUANTEPEC. THE RIDGE WILL ERODE TODAY AND THE PRES GRADIENT WILL RELAX. EXPECT THESE CONDITIONS TO RETURN WED NIGHT AS RIDGING BUILDS AGAIN IN THE SW N ATLC. I RELIED ON THE HIGHER RESOLUTION GFS FOR THE FORECAST HERE. THE 00Z ECMWF WAS FAVORED FOR ADJUSTING THE FORECAST. I RELIED ON THE NWPS PRIMARILY FOR SEAS IN THE CARIBBEAN...BUT IT APPEARS LOW WITH SEAS IN THE TROPICAL N ATLC COMPARED TO OBSERVATIONS. THE EC WAVE WAS BLENDED WITH THE PREVIOUS FORECAST TO ADJUST FOR THE BOTH THE PREFERENCE TOWARD AN ECMWF-LIKE WIND SOLUTION IN THE NORTHERN STREAM AND THE LOW VALUES SEEN IN THE NWPS COMPARED TO BUOY OBSERVATIONS AND ALTIMETER PASSES INITIALLY. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z GFS FAVORED OVER NE WATERS THIS AFTERNOON AND TONIGHT. THE 00Z ECMWF WAS BLENDED WITH THE PREVIOUS OFFICIAL FORECAST. A BLEND OF THE TAFB NWPS AND EC WAVE WITH THE PREVIOUS FORECAST USED FOR WAVE PARAMETERS. MEDIUM- LOW CONFIDENCE. THE GFS COMPARES BEST WITH THE 15Z UTC ASCAT PASS WHICH SHOWED 20-25 KT S WINDS AHEAD OF THE COLD FRONT STRETCHED OVER NW WATERS. THE STRONGER GFS IS PREFERRED WITH THE WINDS HERE THROUGH TONIGHT. OTHERWISE...THE 00Z ECMWF IS PREFERRED AMONG THE LATEST GLOBAL MODELS WITH THE LOW PRES SYSTEM MOVING OUT OF THE GULF OF MEXICO MON. AS THE LOW MOVES INTO THE ATLC...CONFIDENCE IN THE ECMWF WANES A BIT. IT BECOMES A STRONGER AND FASTER SOLUTION THAN THE MODEL CONSENSUS AND IS STRONGER AND FASTER THAN ITS ENS MEAN. BLENDING THE 00Z ECMWF WITH THE PREVIOUS FORECAST FLATTENS OUT THE SYSTEM OVER THE CENTRAL ATLC...ESPECIALLY AS IT DIVERGES SIGNIFICANTLY FROM THE OTHER FORECASTS BY TUE. THE GEFS IS PREFERRED FOR A DEEPER AND MORE NORTHERLY LOW TRACK LIKE THE ECMWF BY THIS TIME WHILE THE 12Z GFS IS LESS AMPLIFIED. THE EC WAVE AND LATEST TAFB NWPS WERE USED TO ADJUST THE SEAS. THE EC WAVE IS PERFORMING BETTER COMPARED TO OBSERVATIONS WITH THE NORTHERLY SWELL MOVING INTO THE REGION...AS IT GENERALLY DOES...VERSUS THE NWPS. THE NWPS WAS WEIGHED HEAVILY IN THE BAHAMAS WHERE ITS HIGH RESOLUTION BATHYMETRY IS ESPECIALLY IMPORTANT TO THE FORECAST. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 MT. NATIONAL HURRICANE CENTER.