000 AGXX40 KNHC 180751 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 251 AM EST WED FEB 18 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 NAM USED TO ADJUST WINDS THROUGH FRI NIGHT. 00Z ECMWF USED TO ADJUST WINDS OVER THE WEEKEND. 00Z NWPS USED TO ADJUST WAVES THROUGH FRI NIGHT THEN THE EC WAVE USED OVER THE WEEKEND. MEDIUM CONFIDENCE. THE 0410 UTC ASCAT-B PASS SHOWS GALE FORCE WINDS ALONG THE COAST OF VERACRUZ FROM 19N TO 20N. THE OBSERVATION AT SACRIFICE ISLAND...SACV4...HAS BEEN REPORTING WINDS IN THE 30-35 KT RANGE SINCE 02Z. NONE OF THE MODELS OR ENSEMBLES ARE PICKING UP ON THE GALE CONDITIONS INITIALLY. THE 00Z 20 KM NAM IS DOES SHOW GALE FORCE WINDS AT 12Z...ENDING AT 18Z. THE 21Z SREFS ONLY SHOW A CHANCE OF GALES...5 PERCENT...AT 12Z THIS MORNING. OBVIOUSLY...THE MODELS ARE HANDLING THIS EVENT RATHER POORLY. WITH A SURGE OF ARCTIC AIR EXPECTED TO MOVE INTO THIS AREA BETWEEN 09Z AND 12Z THIS MORNING...BELIEVE THE GALE SHOULD PERSIST INTO THE DAYLIGHT HOURS. THE NAM SHOWS 30 KT WINDS CONTINUING UNTIL 00Z AND THE QUARTER DEGREE DIPS THE WINDS BELOW 30 KT AT 18Z. SINCE THE NAM HAD THE BEST HANDLE ON THE CURRENT CONDITIONS...WILL HOLD ONTO THE GALE WARNING INTO THE AFTERNOON. THE 00Z GFS BECOMES A SLOW AND STRONG OUTLIER MOVING THE NEXT SYSTEM THROUGH THE SOUTHERN PLAINS OF THE UNITED STATES BY SAT. THE GFS IS STRONGER THAN THE ECMWF WITH THE SE RETURN FLOW IN THE NW AND N CENTRAL GULF SAT AND THE ECMWF IS FASTER TO CARRY THE FRONT TO THE GULF COAST THAN THE GFS SUN MORNING. HOWEVER...THE GFS ALLOWS THE FRONT TO DIVE S THROUGH THE W GULF SUN AND SUN NIGHT WHILE THE ECMWF AND THE OTHER MODELS KEEP THE FRONT STRETCHED MORE E TO W ACROSS THE N GULF. THE ECMWF IS CLEARLY MORE IN LINE WITH THE MODEL CONSENSUS...SO IT AND ITS WAVE MODEL WERE USED TO ADJUST THE FORECAST OVER THE WEEKEND. ...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 IN THE CARIBBEAN. THE EC WAVE WAS USED IN THE ATLC. HIGH CONFIDENCE THROUGH SAT NIGHT THEN MEDIUM CONFIDENCE. A COLD FRONT WILL MOVE THROUGH THE YUCATAN CHANNEL LATER THIS MORNING. BY THU MORNING...BOTH THE GFS AND ECMWF EXTEND THE FRONT FROM EASTERN CUBA TO EASTERN HONDURAS. BY THU EVENING...THE FRONT SHOULD MOVE THROUGH THE WINDWARD PASSAGE. A GALE MAY BE POSSIBLE IN THE WINDWARD PASSAGE THU EVENING BEHIND THE FRONT AFTER IT IS INVIGORATED BY A SURGE OF COLDER AIR. THE QUARTER DEGREE GFS SHOWS 30 KT WINDS HERE AT THAT TIME. WILL CONTINUE TO HOLD OFF ON A GALE HERE AS THE 00Z GFS DOES NOT SHOW THE 30 KT WINDS PERSISTING DESPITE A FAVORABLE DIRECTION FOR FUNNELING CONTINUING THROUGH 12Z SAT. GIVEN THE STRENGTH OF THE ARCTIC AIRMASS EXPECTED TO DRIVE THE FRONT...WILL GIVE THE EDGE TO THE GFS WHICH HAS A SLIGHTLY STRONGER FORECAST. THE 00Z GFS WILL BE USED TO ADJUST THE PREVIOUS FORECAST HERE THROUGH SUN NIGHT. THE NWPS SEEMS REASONABLE TONIGHT THROUGH SUN NIGHT. GALE CONDITIONS ARE EXPECTED ALONG THE COAST OF COLOMBIA EARLY SAT MORNING AS HIGH PRES MOVES IN BEHIND THE COLD FRONT...WITH WINDS TO 40 KT POSSIBLE BY LATE SAT NIGHT AND GALE CONDITIONS EXPECTED TO PERSIST THROUGH SUN NIGHT. AS EXPLAINED IN THE GULF OF MEXICO SECTION...THE GFS IS A STRONG OUTLIER WITH THE COLD FRONT IN THE GULF OF MEXICO SUN AND SUN NIGHT. THE 00Z GFS ALLOWS RIDGING TO THE E OF THE FRONT TO REMAIN IN PLACE N OF THE CARIBBEAN SLIGHTLY LONGER THAN THE OTHER MODELS. WHILE THE DIFFERENCE OVER THE CARIBBEAN ARE RELATIVELY MINOR...THE ECMWF WAS USED ON SUN TO ADJUST THE FORECAST TO BE CONSISTENT WITH THE MODEL PREFERENCE IN THE GULF OF MEXICO. THIS SHOULD BRING WINDS DOWN SLIGHTLY NEAR THE COAST OF COLOMBIA...BUT SHOULD NOT IMPACT THE TIMING OF THE GALES. THE NWPS LOOKS GOOD FOR SEAS HERE. AS EXPLAINED BELOW...THE MWW3 AND NWPS HAVE BEEN TOO LOW WITH LONG PERIOD SWELL IN THE ATLC. THE EC WAVE WAS USED TO ADJUST SEAS HERE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 00Z GFS USED TO ADJUST WINDS THROUGH SAT NIGHT WITH THE ECMWF USED SUN AND SUN NIGHT. 00Z EC WAVE USED TO ADJUST WAVES. MEDIUM CONFIDENCE. THE ASCAT-B PASS FROM AROUND 0230Z SHOWED SW WINDS JUST BELOW GALE FORCE AHEAD OF THE FRONT OFF THE N FLORIDA COAST. AN 02Z JASON2 PASS SHOWS SEAS TO 12.5 FT IN THIS AREA. GIVEN THE OBSERVATIONS...THE 00Z GFS APPEARS SLIGHTLY WEAK HERE INITIALLY. WILL BUMP UP THE WINDS AND SEAS A NOTCH THROUGH THIS MORNING. A SURGE OF ARCTIC AIR WILL MOVE IN BEHIND THE FRONT LATER TODAY. THE MODELS ARE SIMILAR IN THEIR DEPICTION OF THIS SURGE...BUT THE GFS IS A BIT STRONGER THAN THE ECMWF WITH A SECOND SURGE THAT IS EXPECTED EARLY THU MORNING. THE GFS SHOWS A LARGER AREA OF 30 KT WINDS IN NW WATERS AS A RESULT. THE 00Z GEFS SHOWS UP TO A 40 PERCENT CHANCE OF GALES AT THAT TIME. GIVEN THE GENERAL LOW- BALLING SEEN IN THE MODELS COMPARED TO OBSERVATIONS TODAY...WILL GO WITH A GALE WARNING IN NW WATERS AT 06Z THU AND LEAN TOWARD THE STRONGER GFS TO ADJUST THE FORECAST. AS EXPLAINED IN THE GULF OF MEXICO SECTION...THE ECMWF IS PREFERRED OVER THE GFS WITH THE SYSTEM MOVING INTO THE GULF ON SUN. THE FORECAST WAS ADJUSTED TO THE ECMWF ON SUNDAY HERE AS WELL WHICH MEANT WEAKENING THE SE RETURN FLOW AND SLOWING DOWN THE NEXT COLD FRONT JUST NW OF THE AREA SUN NIGHT. THE MWW3 CONTINUES TO BE 3-4 FT TOO SMALL WITH THE LARGE NW SWELLS OVER THE ATLC WATERS. SINCE THE NWPS BOUNDARY CONDITIONS COME FROM THE MWW3...IT IS ALSO TOO LOW WITH THE SWELL. IN ADDITION...THE ECMWF IS CLOSER TO THE MODEL CONSENSUS OVER THE WEEKEND WITH THE NORTHERN STREAM PATTERN. THE EC WAVE WAS USED TO ADJUST THE WAVES. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE WARNING EARLY TODAY INTO TODAY. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... GALE CONDITIONS POSSIBLE FRI NIGHT. GALE CONDITIONS POSSIBLE SAT NIGHT INTO SUN NIGHT. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... GALE WARNING EARLY TODAY INTO TONIGHT. .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... GALE WARNING TODAY INTO TONIGHT. $$ *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.