000 AGXX40 KNHC 221930 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EST TUE NOV 22 2011 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... BUOYS OBSERVATIONS SHOW WINDS ARE BEGINNING TO DIMINISH AHEAD OF THE COLD FRONT OVER E TEXAS COMPARED TO THE 1538 UTC ASCAT PASS. RADAR SHOWS A LINE OF STRONG THUNDERSTORMS PASSING THROUGH THE COASTAL ZONES AND APPROACHING THE FAR NW PORTION OF THE OFFSHORE WATERS. THIS LINE IS EXPECTED TO HOLD TOGETHER INTO THE EVENING AS THE FRONT MOVES OFF THE COAST. THE FRONT WILL REACH FROM THE FL PANHANDLE TO TAMPICO MEXICO WED MORNING...WITH 20 TO 25 KT WINDS FUNNELING S DOWN THE MEXICAN COAST. DEEP LAYER RIDGING WILL BUILD OVER THE WESTERN GULF BY THU AND THIS WILL DEPRIVE THE FRONT OF SUPPORT THERE...BUT THE MAIN THRUST OF THE COLD FRONT WILL CONTINUE TO PUSH SE OUT OF THE EASTERN GULF THROUGH FRI AND THE UPPER TROUGH SUPPORTING IT WILL AMPLIFY OVER THE SE N ATLC. IN TURN...THIS WILL AMPLIFY THE RIDGE OVER THE GULF AS WELL AS THE SOUTHERN STREAM TROUGH MOVING INTO THE SOUTHERN PLAINS AND N CENTRAL MEXICO FRI. THE MODELS AGREE ON PHASING THIS TROUGH WITH A NORTHERN STREAM TROUGH BY SAT AND SEND THE MERGED COLD FRONT INTO THE WESTERN GULF BY SAT NIGHT. THE 12Z GFS...UKMET...NOGAPS AND ECMWF ALL AGREE ON GALES IN THE WESTERN GULF WITH THE GFS THE MOST BULLISH OF THE MODELS. THE 12Z GEFS NOW SHOWS A 40 PERCENT CHANCE OF GALES IN THE SW GULF. THE MODELS DIFFER WITH THE TIMING OF THE FRONT...WITH THE ECMWF THE SLOWEST SOLUTION. FOR NOW...GENERALLY STUCK WITH THE GFS BUT LEANED LIGHTER WITH THE STRONGEST WINDS BEHIND THE FRONT. THIS CONFINES THE GALE WARNING TO THE SW GULF ZONE AND CAPS WINDS AT 35 KT. THE GFS BRINGS WINDS TO STORM FORCE IN THE FAR SW GULF SUN MORNING...BUT NONE OF THE OTHER MODELS ARE CLOSE TO THIS STRENGTH. SW N ATLC W OF 55W... TRADE WINDS ARE SLACKENING OVER THE BAHAMAS S OF 26N AS THE 1023 MB SURFACE HIGH NEAR 31N73W IS BEING IMPINGED UPON BY A COLD FRONT TO ITS N AND ANOTHER APPROACHING FROM THE W. SOUTHERLY FLOW OFF N FL WILL INCREASE TONIGHT AND EARLY WED...AHEAD OF THE COLD FRONT THAT WILL PUSH OFF THE N FL COAST BY LATE WED. THE FRONT WILL EXTEND FROM NEAR BERMUDA TO THE STRAITS OF FLORIDA BY LATE THU. BY FRI...THE MODELS DIVERGE SIGNIFICANTLY AS THE PATTERN BECOMES MORE AMPLIFIED. THE 12Z ECMWF AND UKMET LEAVE BEHIND A CUT OFF LOW S OF BERMUDA OVER THE WEEKEND WHILE THE GFS AND CMC ARE MORE PROGRESSIVE...CARRYING THE BULK OF THE ENERGY EASTWARD AND N OF THE AREA BY SAT NIGHT. THIS MAKES A HUGE DIFFERENCE AT THE SURFACE WHERE THE ECMWF GENERATES 30 KT WINDS NW OF ITS 1012 MB SURFACE LOW NEAR 28N66W SAT EVENING WHILE THE GFS CARRIES A TROUGH ALONG 55W-60W WITH ONLY A SMALL AREA OF N WINDS TO 25 KT MUCH FARTHER E THAN THE ECMWF. THE GFS IS TRENDING TOWARD A MORE PHASED SOLUTION COMPARED TO ITS 00Z RUN WHILE THE ECMWF IS MORE CONSISTENT. CONFIDENCE IS LOW HERE. THE CURRENT FORECAST IS CLOSER TO THE 12Z GFS SOLUTION. CARIBBEAN SEA AND TROPICAL N ATLC S OF 19N W OF 55W... THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE N OF THE AREA...AND LOW PRESSURE ASSOCIATED WITH THE MONSOON TROUGH OVER THE SW CARIBBEAN IS SUPPORTING FRESH TO STRONG NE TO E WINDS AS DEPICTED BY THE LATEST ASCAT SCATTEROMETER PASSES AT 1400 AND 1540 UTC. THE GRADIENT WILL WEAKEN THROUGH WED AS HIGH PRESSURE SHIFTS EASTWARD AHEAD OF THE FRONT IN THE GULF OF MEXICO. WINDS WILL DIMINISH AND NE SWELL WILL DECAY TO LESS THE 8 FT BY WED EVENING. FRESH NE WINDS RETURN TO THE NW CARIBBEAN BY FRI AS HIGH PRES BUILDS N OF THE AREA BEHIND THE GULF OF MEXICO COLD FRONT. THE LAST FEW RUNS OF THE GFS HAVE TRIED TO DEVELOP A LOW PRES SYSTEM IN THE SW GULF ALONG THE MONSOON TROUGH BY THE WEEKEND. THE UKMET IS TRENDING TOWARD DEVELOPING AN AREA OF LOW PRES HERE AS WELL. THE CURRENT FORECAST DOES NOT SHOW A LOW HERE AND BACKS OFF ON THE FRESH N WINDS THAT THE GFS FUNNELS ALONG THE CENTRAL AMERICAN COAST W OF THE LOW. THIS MAY NEED TO BE REVISITED BY THE NEXT SHIFT. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER