000 AGXX40 KNHC 260801 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 301 AM EST THU DEC 26 2013 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: BLEND OF GFS AND ECMWF WITH THE PREVIOUS FORECAST FOR WIND. MWW3 BLENDED WITH PREVIOUS FORECAST FOR WAVES. MEDIUM CONFIDENCE. THE ASCAT PASSES FROM 0338Z AND 0244Z SHOW FRESH TO STRONG NE WINDS IN THE S CENTRAL GULF WHERE ENERGY FROM THE DISSIPATING STATIONARY FRONT FOUND IN THE VICINITY HAS BEGUN TO CONSOLIDATE. LIGHTNING DATA SHOWS ACTIVE CONVECTION IN THIS REGION...AND THE ASCAT PASSES SUGGEST A NORTH-SOUTH TROUGH IS DEVELOPING JUST N OF THE YUCATAN CHANNEL. THE 00Z GFS AND ECMWF AGREE ON THE DEVELOPMENT OF THIS SURFACE TROUGH BUT ARE WEAK INITIALLY WITH THE WINDS HERE. ADJUSTMENTS WILL BE MADE TO THE GRIDS TO ACCOUNT FOR THESE STRONGER WINDS. LATER IN THE FORECAST PERIOD...THE MODELS AGREE ON CARRYING THE MID-LEVEL ENERGY FOUND HERE NORTHWESTWARD THU THROUGH SAT...EVENTUALLY CONVERGING THIS ENERGY WITH THE ENERGY CURRENTLY FORCING A TROUGH IN THE SW GULF AS A LARGE-SCALE TROUGH MAKES ITS WAY THROUGH THE WESTERN GULF. THE 00Z GFS AND ECMWF HAVE COME INTO REASONABLE AGREEMENT ON THE DEVELOPMENT OF A SURFACE LOW IN THE SW PORTION OF THE GULF EARLY SAT THAT MAKES ITS WAY NE TOWARD THE FLORIDA PANHANDLE BY EARLY SUN. THIS IS A REASONABLY LARGE CHANGE IN THE FORECAST COMPARED TO THIS TIME LAST NIGHT...BUT THE NAVGEM AND UKMET ALSO SHOW THE SAME SCENARIO. THE DIFFERENCES IN THE MODELS ARE WITH THE STRENGTH OF THE SURFACE LOW. THE BULK OF THEM SUPPORT THE STRONGER GFS SOLUTION OVER THE WEAKER 00Z ECMWF. THE GFS WAS ON THE STRONG END OF THE GUIDANCE SUITE LAST NIGHT AND THE OTHER MODELS HAVE COME AROUND TO ITS SCENARIO. A BLEND OF THE PREVIOUS FORECAST WITH THE LATEST GFS AND ECMWF WAS USED TO ACCOUNT FOR UNCERTAINTY IN THIS STILL EVOLVING FORECAST...WITH THE LARGEST WEIGHT GIVEN TO THE GFS. THE MWW3 WAS USED TO ADJUST THE WAVE FORECAST. THE NWPS WAS NOT USED BECAUSE OF THE LARGE CHANGE TO THE WIND FORECAST. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 65W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS FORECAST FOR WIND. NWPS/MWW3 BLENDED INTO PREVIOUS FORECAST FOR WAVES. HIGH CONFIDENCE. THE TRADE WINDS HAVE GENERALLY DIMINISHED ACROSS THE CARIBBEAN AND TROPICAL N ATLC WITH THE PRESSURE GRADIENT SIGNIFICANTLY WEAKENED BETWEEN HIGH PRES TO THE NE AND THE DISSIPATING STATIONARY FRONT N OF CUBA AND A SURFACE TROUGH STRETCHING NE FROM THE WINDWARD PASSAGE WHICH IS INTERACTING WITH A MID TO UPPER LEVEL LOW. A BROAD UPPER JET HAS A LEFT FRONT QUADRANT ON THE SE SIDE OF THIS LOW. UPPER DIFFLUENCE HERE IS PROVIDING LIFT NEAR THE WINDWARD ISLANDS WHICH IS ENHANCING TROUGHING AND RESULTING IN AN AREA OF FRESH TO STRONG NE WINDS AS SEEN BY THE 0154Z AND 0100Z ASCAT PASSES AND THE 0316 UTC OSCAT PASS. THE 00Z GFS AND ECMWF ARE ABOUT 3-5 KT TOO WEAK WITH THE WINDS HERE. ADJUSTMENTS WILL BE MADE TO ENHANCE THE WIND FIELD UNTIL THU NIGHT WHEN THE JET SHIFTS NORTHEASTWARD. RIDGING WILL BRIEFLY BUILD NE OF THE AREA FRI AND THEN SHIFT WESTWARD OVER THE WEEKEND AS HIGH PRES BEHIND A COLD FRONT MOVING THROUGH THE WESTERN ATLC BECOMES THE DOMINANT PLAYER. THIS WILL ALLOW AN INCREASE IN TRADES...ESPECIALLY NEAR THE COAST OF COLOMBIA WHERE SEAS WILL BE BACK UP TO 8 FT BY FRI NIGHT...THEN BUILDING TO 10-12 FT BY SUN. THE GFS/MWW3 FORECAST SOLUTION LOOKS REASONABLE HERE. BLENDED IN THE NWPS HERE TO ACCOUNT FOR BATHYMETRY. ...SW N ATLANTIC W OF 65W INCLUDING THE BAHAMAS... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH GFS AND ECMWF FOR WIND. NWPS...MWW3...AND EC WAVE BLENDED WITH PREVIOUS FORECAST FOR WAVES. MEDIUM CONFIDENCE. THE GUIDANCE SUITE HAS TRENDED TOWARD THE MORE CONSISTENT...STRONG GFS SOLUTION WITH THE COLD FRONT EXPECTED TO MOVE INTO NW WATERS LATE SUN AND MON. AS MENTIONED IN THE GULF OF MEXICO SECTION...A BLEND OF THE GFS AND ECMWF LEANING TOWARD THE GFS SEEMS BEST WITH THIS SYSTEM. THIS BLEND ALSO ACCOUNTS FOR UNCERTAINTY EARLIER IN THE PERIOD WITH THE INTERACTION OF THE DISSIPATING STATIONARY FRONT OVER THE AREA AND TROUGHING MOVING N FROM THE CARIBBEAN. THE EC WAVE WAS BLENDED INTO THE MWW3 AND NWPS FORECASTS TO ACCOUNT FOR THE UNCERTAINTY. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER SCHAUER. NATIONAL HURRICANE CENTER.