000 AGXX40 KNHC 021929 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EST SAT FEB 02 2013 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A GENTLE TO MODERATE BREEZE THAT SHIFTS FROM NORTHEASTERLY IN THE E GULF TO SOUTHEASTERLY IN THE NW GULF IS IN PLACE AT THE MOMENT. A WEAK COLD FRONT WILL RACE SE THROUGH THE NORTHEASTERN GULF SUN AND HIGH PRES CENTERED OVER TEXAS SUN MORNING WILL SHIFT EASTWARD INTO N FLORIDA MON. THE MODELS ARE IN REASONABLE AGREEMENT ON THESE RATHER BENIGN CONDITIONS UNTIL LATE MON WHEN THEY BEGIN TO DIVERGE WITH THE STRENGTH AND TIMING OF A VERY WEAK LOW PRES SYSTEM AND COLD FRONT MOVING E FROM TEXAS ACROSS THE NORTHERN GULF. THE 0000 UTC ECMWF IS SLOWER AND WEAKER THAN THE GFS HERE. THE 1200 UTC UKMET AND CMC ARE IN BETTER AGREEMENT WITH THE GFS SOLUTION...WITH THE CMC STRONGER AND FASTER AND THE UKMET WEAKER. CONFIDENCE IS LOW IN THE DETAILS WITH THIS FINE SCALE FEATURE...BUT THE GFS SEEMS LIKE THE BETTER CHOICE FOR ADJUSTING THE FORECAST. REGARDLESS...WINDS AND SEAS SHOULD REMAIN BELOW ADVISORY CRITERIA. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... THE 1438 UTC ASCAT PASS SHOWS FAIRLY UNIFORM NE WINDS S OF CUBA. SURFACE OBSERVATIONS DO NOT REVEAL MUCH OF A PRESSURE TROUGH OR WIND SHIFT...SO THE STATIONARY BOUNDARY THAT HAD EXTENDED FROM EASTERN CUBA TO CENTRAL HONDURAS THIS MORNING WAS DISSIPATED. THIS ASCAT PASS MISSED THE FRESH TO STRONG WINDS BELIEVED TO BE ALONG THE COLOMBIAN COAST THIS MORNING. THE AREA OF FRESH TO STRONG WINDS OFF THE COAST OF COLOMBIA WILL TEMPORARILY SHRINK SUN INTO MON AS A COLD FRONT MAKES ITS WAY THROUGH THE SW N ATLC...WEAKENING RIDGING THERE AND DIMINISHING THE PRES GRADIENT BETWEEN ATLC RIDGING AND LOW PRES OVER NORTHERN SOUTH AMERICA. THIS COLD FRONT MOVING THROUGH THE SW N ATLC SUN WILL CLIP THE NW CARIBBEAN BY SUN NIGHT...BRINGING A FRESH NE BREEZE AND SEAS TO 7 FT THAT WILL SUBSIDE MON. OVERALL...THE GFS/WW3 HAVE A REASONABLE FORECAST FOR THE CARIBBEAN. IN THE TROPICAL N ATLC...THE WW3 HAS COME INTO GOOD AGREEMENT WITH THE ECMWF WAVE WITH THE SUBSIDING NE SWELL LATE SUN THROUGH MON. BY LATE TUE/EARLY WED...SWELL FROM THE STRONG COLD FRONT PASSING THROUGH THE SW N ATLC SUN/MON. A BLEND OF THE WW3 AND ECMWF WAVE MODEL WAS PREFERRED FOR SEAS HERE AND WAS USED TO UPDATE THE GRIDS IN THE TROPICAL N ATLC AS WELL FROM LATE TUE ONWARD. SW N ATLC S OF 31N W OF 55W... A STATIONARY FRONT EXTENDS FROM 31N58W THROUGH THE SE BAHAMAS TO EASTERN CUBA AND A SECOND FRONTAL BOUNDARY LIES TO ITS N FROM NEAR 31N62W TO 28N76W. BOTH BOUNDARIES ARE FORECAST TO MOVE NORTHWARD AHEAD OF A STRONG COLD FRONT THAT WILL MOVE OFF THE NE FLORIDA COAST SUN. THE SECOND FRONTAL BOUNDARY WILL DISSIPATE THIS EVENING WHILE THE EASTERN MOST FRONT WILL GRADUALLY BE ABSORBED BY THE STRONG COLD FRONT ON SUN NIGHT. DESPITE THIS COMPLEX SCENARIO...THE 1200 UTC GFS AND 0000 UTC ECMWF SHOW GENERAL AGREEMENT ON THE FORECAST. BOTH MODELS HAVE 30 KT W WINDS ALONG 31N BEHIND THE STRONG COLD FRONT BY 1800 UTC SUN. THE ECMWF CARRIES A GALE FORCE BARB RIGHT AT 31N...BUT THE GFS HAS BACKED OFF COMPARED TO EARLIER RUNS AND THE 1200 UTC GEFS NOW HAS NO CHANCE OF A GALE HERE WHERE THE 0600 UTC RUN HAD SHOWED A 30 PERCENT CHANCE WILL SIDE WITH THE MORE RECENT GFS FORECAST CYCLE HERE. SEAS ARE ANOTHER STORY...WITH THE WW3 RUNNING 2-4 FT LOWER THAN THE ECMWF WITH MAX SEAS BEHIND THE FRONT. THE SLIGHTLY WEAKER WIND FIELD OVER AND NEAR THE FORECAST AREA DOES NOT ACCOUNT FOR THESE LARGE DIFFERENCES. THE UKMET WAVE LIES BETWEEN THESE TWO SOLUTIONS. WITH THE DETERMINISTIC METEOROLOGICAL RUNS COMING INTO BETTER AGREEMENT WITH THE EVOLUTION OF THE ANCHOR LOW PRESSURE SYSTEM WELL TO THE N...WOULD PREFER TO LEAN TOWARD THE MIDDLE-OF-THE-ROAD WAVE SOLUTION. A BLEND OF THE WW3 AND ECMWF WAVE WAS USED TO UPDATE THE GRIDS WITH SWELL AND WIND-WAVES ASSOCIATED WITH THIS SYSTEM. MORE DIFFERENCES COME INTO PLAY BY WED OVER NW WATERS WHERE THE ECMWF IS FASTER THAN THE GFS CARRYING A COLD FRONT OFFSHORE. THIS FRONT IS RELATED TO THE SYSTEM DISCUSSED FOR LATE MON/TUE IN THE GULF OF MEXICO SECTION. THE WEAKER ECMWF BECOMES THE FASTER MODEL WITH THE FRONT AS IT MOVES IN THE SW N ATLC...PHASING THIS SOUTHERN STREAM SYSTEM INTO THE LEADING EDGE OF THE MEAN TROUGH MORE RAPIDLY THAN THE GFS. THE GFS IS PREFERRED WITH THIS SYSTEM...WHICH MEANS LIGHTER WINDS AND LOWER SEAS THAN THE ECMWF AND ITS WAVE MODEL. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER