000 AGXX40 KNHC 160753 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 253 AM EST MON FEB 16 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 GFS AND NAM USED TO ADJUST WINDS. 00Z NWPS USED TO ADJUST WAVES. MEDIUM CONFIDENCE. INITIALLY...THE 00Z ECMWF AND GFS AGREE ON CARRYING THE NEXT COLD FRONT INTO THE NW GULF LATE MON AFTERNOON...PLACE THE FRONT FROM NEAR TAMPA BAY TO THE SW GULF BY TUE EVENING AND SEND THE FRONT SE OF THE AREA WED MORNING WHEN A REINFORCING SURGE OF COLD NORTHERLY FLOW INCREASES WINDS BEHIND THE FRONT. THE PROBLEM OF THE DAY IS WHETHER TO KEEP THE GALE WARNING NEAR THE COAST IN THE SW GULF ZONE (GMZ023) FOR OVERNIGHT TUE NIGHT INTO WED. NEITHER THE GFS NOR THE ECMWF SHOW A GALE HERE. THE QUARTER DEGREE GFS CAPS WINDS AT 30 KT WHEN THE FRONT GOES THROUGH LATE TUE AFTERNOON AND ALLOWS WINDS TO GET BACK TO 30 KT FOR 12Z AND 18Z WED. THE LOWER RESOLUTION ECMWF NEVER SHOWS WINDS OVER 25 KT HERE...AND THE LOWER RESOLUTION 00Z GEFS SHOWS NO CHANCE OF GALE. THE 20 KM NAM SHOWS GALE FORCE N-NW WINDS S OF 20N AND W OF 95W AT 12Z AND 18Z WED...AT THE SAME TIME THAT THERE IS A 30 PERCENT CHANCE OF GALES IN THE 21Z SREF. THE SREF SHOWS LESS THAN A 10 PERCENT CHANCE OF A GALES AS THE FRONT MOVES THROUGH LATE TUE AFTERNOON. IT APPEARS THAT THE REINFORCING ARCTIC SHORTWAVE THAT INCREASES THE NORTHERLY FLOW BEHIND THE FRONT IS DRIVER FOR A POSSIBLE GALE HERE...DELAYING A GALE WARNING TILL WED MORNING AS OPPOSED TO WITH THE FRONTAL PASSAGE. THE HIGHEST RESOLUTION GUIDANCE HAS AN EDGE HERE GIVEN THAT A GALE HERE WILL BE ENHANCED BY THE FUNNELING EFFECT OF THE HIGH TERRAIN NEAR THE COAST CLOSE TO 20N. WILL SIDE WITH THE NAM AND SREF...KEEPING THE GALE AND DELAYING IT TILL WED MORNING. OTHERWISE...THE GFS LOOKS REASONABLE ACROSS THE GULF AND SUGGESTS LITTLE CHANGE TO THE PREVIOUS FORECAST...ALLOWING THE NWPS TO BE A GOOD CHOICE FOR ADJUSTING THE WAVES. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 00Z GFS USED TO ADJUST WINDS. 00Z NWPS USED TO ADJUST WAVES. HIGH CONFIDENCE. BAGGY HIGH PRESSURE OVER THE STRAITS OF FLORIDA AND THE SE GULF OF MEXICO HAS INCREASED THE PRESSURE GRADIENT BETWEEN IT AND LOW PRES OVER COLOMBIA. GALE CONDITIONS ARE EXPECTED THIS MORNING OFF THE COAST OF COLOMBIA AND RECENT SCATTEROMETER PASSES SHOW FRESH TO STRONG NE WINDS ARE ALSO IN PLACE IN THE LEE OF CUBA AND S OF HISPANIOLA. THE QUARTER DEGREE GFS FORECASTS GALE CONDITIONS AT 06Z AND 12Z THIS MORNING AND AGAIN AT 00Z THIS EVENING AND ENDING AT 18Z TUE BEFORE THE GRADIENT DIMINISHES AS HIGH PRES MOVES EASTWARD. WITH WINDS ALREADY STRONGER THAN EXPECTED THIS TIME LAST NIGHT IN THE LEE OF CUBA AND S OF HISPANIOLA...CONFIDENCE IS RELATIVELY HIGH IN THE QUARTER DEGREE GFS. THE GFS LIKELY HAS THE BEST HANDLE ON THE TERRAIN IMPACTS NEAR THE COAST IN ALL OF THESE REGIONS AS WELL AS IN THE WINDWARD PASSAGE WHERE A RECENT RAPIDSCAT PASS SHOWS 25 KT WINDS. A NEW FRONT WILL MOVE INTO THE NW CARIBBEAN BY WED MORNING. BY THU MORNING...BOTH THE GFS AND ECMWF EXTEND THE FRONT FROM EASTERN CUBA TO EASTERN HONDURAS...WITH THE GFS INCREASING WINDS TO A STRONG BREEZE BEHIND THE FRONT FASTER THAN THE ECMWF. GIVEN THE STRENGTH OF THE ARCTIC AIRMASS EXPECTED TO DRIVE THE FRONT...WILL CONTINUE TO GIVE THE EDGE TO THE GFS WITH THE FORECAST. THE 00Z GFS WILL BE USED TO ADJUST THE PREVIOUS FORECAST HERE THROUGH FRI NIGHT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 00Z GFS USED TO ADJUST WINDS. 00Z NWPS USED TO ADJUST WAVES. MEDIUM CONFIDENCE. THREE SCATTEROMETER PASSES BETWEEN 01Z AND 03Z SHOW GALE FORCE WINDS IN THE AREA N OF 29N BETWEEN 60W AND 71W. BOTH THE 00Z GFS AND ECMWF WERE TOO WEAK HERE...WITH BOTH MODELS ONLY SHOWING A SMALL AREA OF GALE FORCE WINDS NEAR 31N65W AT 00Z. THE 00Z GEFS SHOWS A CHANCE OF GALE FORCE WINDS OVER WATERS N OF 30 06Z MON...BUT EVEN THE GEFS PROBABILITIES DO NOT DO JUSTICE TO THE OBSERVATIONS. BUMPING UP THE VALUES A BIT WOULD SUGGEST THE GALE WARNING SHOULD PERSIST THROUGH 12Z. WINDS AND SEAS WERE ADJUSTED UP OVER THE FIRST FEW PERIODS TO MATCH THE OBSERVATIONS. AS MENTIONED IN THE GULF OF MEXICO SECTION...THE GFS IS THE PREFERRED SOLUTION WITH THE COLD FRONT MOVING THROUGH THE GULF TODAY THROUGH TUE BEFORE PASSING OFF THE SE GEORGIA COAST BY TUE AFTERNOON. THE ECMWF AND GFS AGREE ON THIS TIMING. THE 00Z GFS SHOWS GALES AHEAD OF THE FRONT FROM 12Z TUE THROUGH 00Z THU WHILE THE LOWER RESOLUTION ECMWF NEVER GETS WINDS TO 35 KT. THE 00Z GEFS ALSO NEVER SHOWS MORE THAN A 5 PERCENT CHANCE OF GALES... PREFERRING TO KEEP GALES JUST N OF THE AREA. SINCE THE MODELS HAVE HAD A TENDENCY TO BE TOO WEAK WITH THE WINDS OVER N WATERS ASSOCIATED WITH THESE ARCTIC AIR MASSES...WILL CONTINUE TO USE THE HIGHER RESOLUTION GFS TO ADJUST THE FORECAST AND BUMP UP THE WINDS/WAVES SLIGHTLY TO ACCOUNT FOR THE BIAS. AS IN THE GULF...THE FRONT WILL BE INVIGORATED BY A SURGE OF ARCTIC AIR WED MORNING. WILL KEEP THE GALE GOING FROM 12Z TUE THROUGH 00Z THU AS THE QUARTER DEGREE GFS SUGGESTS. THE NWPS SEEMS REASONABLE FOR ADJUSTING THE WAVES...WITH SOME ADJUSTING OF SEAS TOWARD THE STRONGER WINDS THAN PREVIOUSLY FORECAST. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE CONDITIONS POSSIBLE WED. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... GALE WARNING EARLY TODAY. GALE WARNING TONIGHT. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ111...ATLANTIC FROM 27N TO 31N W OF 77W... GALE WARNING TONIGHT INTO TUE. .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... GALE WARNING TUE. .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... GALE CONDITIONS POSSIBLE WED. $$ *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.