000 AGXX40 KNHC 060720 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 220 AM EST SUN JAN 06 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... THE 0308 UTC ASCAT PASS SHOWS WINDS BETWEEN THE MEXICAN COAST AND THE FRONT STRETCHED FROM TAMPA BAY THROUGH 27N94W TO 19N92W HAVE DIMINISHED TO 25 KT. THE THICKNESS GRADIENT IN THIS REGION IS EXPECTED TO TIGHTEN LATER TODAY AS A NORTHERN STREAM TROUGH PROVIDES A SECONDARY SURGE OF NORTHERLY FLOW TO THE WESTERN GULF. HOWEVER...THIS SURGE IS NOT EXPECTED TO BE PARTICULARLY STRONG. WINDS ARE EXPECTED TO TOP OFF AROUND 25 KT WITH SOME ISOLATED AREAS OF 30 KT NEAR THE COAST. LATER IN THE PERIOD...THE GLOBAL MODELS HAVE COME INTO REASONABLE AGREEMENT WITH THE NEXT SYSTEM TO MOVE INTO THE GULF. THEY ALL AGREE ON CARRYING A CUT OFF LOW THROUGH THE SOUTHWESTERN U.S. AND INTO THE SOUTHERN PLAINS BY WED...WITH THE 0000 UTC ECMWF THE SLOWEST SOLUTION. THE ECMWF HAS CONSISTENTLY CARRIED A STRONG CUT OFF LOW ON THIS TRAJECTORY WHILE THE OTHER MODELS HAVE BEEN LESS CONSISTENT. WILL ADJUST THE FORECAST TOWARD THE CONSISTENT 0000 UTC ECMWF WHICH HAS STRONGER SE RETURN FLOW IN THE WESTERN GULF TUE/WED AHEAD OF THE SYSTEM WITH HIGHER SEAS THAN THE GFS AND WW3. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... AN E-W RIDGE OVER THE SW N ATLC ALONG 26N DOMINATES THE WIND REGIME IN THE CARIBBEAN AND TROPICAL N ATLC. THE 0126 UTC AND 0306 ASCAT PASSES SHOW THE STRONGEST WINDS LIES OVER THE CENTRAL CARIBBEAN...WITH WINDS CONFIRMED TO 30 KT ON THE EASTERN EDGE OF A SWATH NEAR 13N78W WHERE ALL OF THE 0000 UTC GLOBAL GUIDANCE ONLY SHOW 25 KT WINDS. UNFORTUNATELY...SCATTEROMETER PASSES HAVE MISSED THE AREA WHERE GALES ARE BELIEVED TO BE OCCURRING ALONG THE COAST OF COLOMBIA. THE 0000 UTC GFS CONTINUES TO CARRY GALE FORCE WINDS HERE. GIVEN THE WEAK INITIALIZATION OF THE MODELS ON THE FRINGE OF THE 30 KT WIND FIELD...WILL CONTINUE TO CARRY THE GALE WARNING THROUGH THE END OF THE DIURNAL MAXIMUM OF WIND HERE AFTER SUNRISE. BY TONIGHT...A COLD FRONT DISRUPTS THE SUBTROPICAL HIGH...PUTTING AN END TO THE GALE. AFTER THE FRONTAL PASSAGE...THE PATTERN BECOMES MORE DEPENDENT UPON THE EVOLUTION OF THE CUT OFF LOW OVER MEXICO/TEXAS WHERE THE ECMWF SOLUTION IS PREFERRED. THE ECMWF IS MORE CONSISTENT THAN THE OTHER MODELS BY BUILDING A LESS AMPLIFIED DEEP-LAYER RIDGE IN THE SW N ATLC AHEAD OF THE CUT OFF LOW. THIS KEEPS THE PRES GRADIENT WEAKER AND THE ECMWF ONLY SHOWS WINDS TO 30 KT TUE-THU. HOWEVER...THE 0000 UTC UKMET AND NOGAPS ARE TRENDING TOWARD SLIGHTLY MORE RIDGING AHEAD OF THE CUT OFF LOW AND ALLOW FOR GALES OFF COLOMBIA BY WED MORNING IN THE NOGAPS AND BY THU MORNING IN UKMET WHILE THE GFS SHOWS GALES TUE-THU MORNINGS. THE 0000 UTC GEFS SHOWS NO CHANCE OF GALES UNTIL WED MORNING AND CARRIES A 50 PERCENT CHANCE OF GALES THU MORNING. GIVEN THE ENSEMBLE SUPPORT FOR THE GLOBAL MODEL MAJORITY...WILL INTRODUCE GALES INTO THE FORECAST BY WED MORNING. A BLEND OF THE 0000 UTC GFS AND ECMWF WILL BE USED TO ADJUST THE FORECAST. SW N ATLC S OF 31N W OF 55W... A FRONTAL BOUNDARY FROM 28N55W TO CAPE CANAVERAL WILL WEAKEN TODAY. THE NEXT DEEP-LAYER TROUGH WILL MOVE OFF THE MID-ATLC U.S. COAST TODAY AND CREATE A WAVE ALONG THE BOUNDARY N OF THE BAHAMAS THAT WILL MOVE NORTHEASTWARD...WITH THE BROAD DEEP-LAYER TROUGH FINALLY PUSHING OFFSHORE AND CARRYING THE FRONT SOUTHEASTWARD THROUGH FLORIDA ON MON. THE 0128 UTC ASCAT PASS SHOWS FRESH WINDS ARE CURRENTLY CONFINED S OF 23N FROM THE WINDWARD PASSAGE EASTWARD. THESE EASTERLY TRADES WILL VERE MORE SOUTHERLY TODAY AS THE FRONTAL BOUNDARY STRENGTHENS. LOOK FOR FRESH WINDS BEHIND THE FRONT ON MON. AS MENTIONED IN THE GULF OF MEXICO SECTION...THE ECMWF IS PREFERRED WITH THE CUT OFF LOW MOVING THROUGH THE SOUTHERN PLAINS BY MIDWEEK. ADJUSTMENTS WILL BE MADE TO THE FORECAST TOWARD THE ECMWF FROM TUE ONWARD. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .GALE WARNING...AMZ031. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER