000 AGXX40 KNHC 200553 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 153 AM EDT FRI MAR 20 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: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST THROUGH SAT. ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST SAT NIGHT THROUGH TUE NIGHT. A BLEND OF THE TAFB NWPS AND 12Z EC WAVE WITH THE PREVIOUS FORECAST USED FOR WAVE PARAMETERS. MEDIUM-LOW CONFIDENCE. THE MODELS DIVERGE SIGNIFICANTLY WITH THE TIMING OF LOW PRES MOVING FROM TEXAS EASTWARD THROUGH THE SOUTHERN PORTION OF THE GULF COASTAL STATES INTO THE FLORIDA PANHANDLE SAT NIGHT THROUGH MON. THE 00Z GFS AND NAVGEM ARE SLOWER THAN THE 00Z UKMET...CMC AND 12Z ECMWF WITH THE LOW. THE GFS IS GENERALLY WEAKER THAN THE 12Z ECMWF WITH THE LOW. THE ECMWF ENS MEAN IS IN GOOD AGREEMENT WITH THE OPERATIONAL RUN WHILE THE GEFS LENDS MORE CREDENCE TO A FASTER SOLUTION IN THE GULF LIKE THE ECMWF. CONFIDENCE IS LOW. A BLEND OF THE PREVIOUS FORECAST AND THE ECMWF...WHICH IS CLOSER TO THE GLOBAL MODEL MEAN FORECAST...WAS USED BEYOND SAT. FOR WAVES...THE EC WAVE SOLUTION WAS ADDED TO THE MIX WITH THE TAFB NWPS IN ORDER TO ACCOUNT FOR THE BLEND 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 TUE NIGHT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS AND 12Z ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE PARAMETERS IN THE CARIBBEAN WITH THE 12Z EC WAVE BLENDED WITH THE PREVIOUS OFFICIAL FORECAST IN THE TROPICAL ATLC. MEDIUM CONFIDENCE. WEAK ATLC RIDGING N OF THE AREA COMBINED WITH LOW PRES OVER NW COLOMBIA WILL SUPPORT PULSES OF 20-25 KT NE WINDS WITHIN 90 NM OF THE COAST OF COLOMBIA EACH NIGHT THROUGH THE PERIOD...DIMINISHING TO 15-20 KT BY LATE MORNING. THE 00Z GFS WAS USED TO POPULATE THIS AREA AS IT HAS THE HIGHEST RESOLUTION AND GENERALLY DOES BEST IN THIS AREA. THERE ARE SOME RESERVATIONS AS THE GFS IS NOT THE PREFERRED SOLUTION WITH THE NORTHERN STREAM PATTERN...BUT DIFFERENCES IN THE PRESSURE GRADIENT BETWEEN THE MODELS SHOULD BE SMALL ENOUGH TO OUTWEIGHED BY LOCAL IMPACT OF THE FUNNELING OF WINDS NEAR THE HIGH TERRAIN HERE. ELSEWHERE...WINDS MAY BRIEFLY PULSE TO A FRESH TO STRONG BREEZE IN THE GULF OF HONDURAS IN THE EVENING AND OVERNIGHT HOURS FRI NIGHT ONWARD DEPENDING ON THE STRENGTH AND TIMING OF THE PROGRESSIVE RIDGE AXES MOVING THROUGH THE STRAITS OF FLORIDA AND SOUTHERN BAHAMAS THROUGH THE FORECAST PERIOD. AS EXPLAINED IN THE GULF OF MEXICO SECTION...A BLEND OF THE GFS AND 12Z ECMWF IS FAVORED. THE NWPS WAS PRIMARILY RELIED ON FOR SEAS IN THE CARIBBEAN...BUT IT APPEARS LOW WITH SEAS IN THE TROPICAL N ATLC. 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: A BLEND OF THE 00Z GFS AND 12Z ECMWF BLENDED WITH THE PREVIOUS OFFICIAL FORECAST THROUGH SAT NIGHT THEN THE ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST SUN THROUGH TUE NIGHT. A BLEND OF THE TAFB NWPS AND EC WAVE WITH THE PREVIOUS FORECAST USED FOR WAVE PARAMETERS. MEDIUM-LOW CONFIDENCE. THE GFS APPEARS TO HAVE SOME CONVECTIVE FEEDBACK PROBLEMS STARTING BY 06Z SAT NEAR 31N70W. WHILE THIS FEEDBACK MAY BE CAUSING THE GFS TO BE SLIGHTLY FAST LOWERING HEIGHTS ON THE E SIDE OF THE TROUGH SKIRTING NE WATERS...IT DOES NOT APPEAR TO APPRECIABLY IMPACT THE FORECAST IN A NEGATIVE MANNER. THE 12Z ECMWF FORECAST WAS BLENDED IN HERE TO BE SAFE. THE 12Z ECMWF IS PREFERRED AMONG THE LATEST GLOBAL MODELS WITH THE LOW PRES SYSTEM MOVING OUT OF THE GULF OF MEXICO SUN AND MON. AS THE LOW MOVES INTO THE ATLC...THE ECMWF BECOMES A COMPROMISE SOLUTION BETWEEN THE MORE QUICKLY WRAPPED UP SOLUTIONS OF THE NAVGEM AND CMC AND THE FLATTER SOLUTIONS OF THE UKMET AND GFS. THE GEFS SHOWS A SLIGHT PREFERENCE TOWARD A DEEPER AND MORE NORTHERLY LOW TRACK LIKE THE 12Z ECMWF OVER THE GFS BY THE END OF THE PERIOD IN THE ATLC. AGAIN...THE ECMWF IS FAVORED FOR ADJUSTING THE PREVIOUS FORECAST. THE 12Z 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 SCHAUER. NATIONAL HURRICANE CENTER.