000 AGXX40 KNHC 201823 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 123 PM EST WED DEC 20 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A DEEPENING STORM SYSTEM OVER WRN OKLAHOMA/KANSAS IS LIFTING NE INTO THE MISSOURI VALLEY WITH A COLD FRONT EXTENDING SW ACROSS SRN TEXAS INTO EXTREME NE MEXICO. THE FRONT WILL REACH THE IMMEDIATE TEXAS COAST BY THIS EVENING THEN DRIFT INTO THE NW GULF OFFSHORE WATERS OVERNIGHT...POSSIBLY BECOMING NEARLY STATIONARY ON THU. A SECOND PUSH OF THE FRONT WILL OCCUR THU NIGHT AND FRI AND INCREASE WINDS BRIEFLY TO 20-25 KT BEHIND THE BOUNDARY. THE FRONT THEN STALLS AGAIN FRI NIGHT FROM THE FLORIDA PANHANDLE TO THE EXTREME SW GULF AS IT LOSES ITS UPPER LEVEL SUPPORT. A THIRD PUSH...WITH POSSIBLE LOW DEVELOPMENT ALONG THE FRONT...WILL OCCUR SAT NIGHT INTO SUN AS A SHORTWAVE CURRENTLY LOCATED N OF THE HAWAIIAN ISLANDS NEARS THE AREA AND BECOMES THE DRIVING FORCE. THERE REMAINS CONSIDERABLE TIMING DIFFERENCES AMONG THE THE VARIOUS GLOBAL MODELS REGARDING ANY TYPE OF LOW DEVELOPMENT OR COLD FRONTAL PASSAGE...AND THEY ALL HINGE ON THE BEHAVIOR OF THE PACIFIC SHORTWAVE. UNFORTUNATELY THINGS MAY NOT BECOME ALL THAT MUCH CLEARER UNTIL IT MOVES INTO THE RADIOSONDE NETWORK...POSSIBLY THU NIGHT (READY FOR THE FRI MORNING SOUNDINGS). IN GENERAL...THE 12Z UKMET APPEARS TO BE THE FASTEST MODEL WITH A LOW OVER THE NE GULF SUN MORNING...THE 00Z ECMWF IS SLOWEST WITH A NE GULF LOW MON EVENING. THE 12Z GFS...12Z GFS ENSEMBLE MEAN...12Z NOGAPS...AND 00Z CANADIAN MEANWHILE LIE SOMEWHERE IN BETWEEN WITH SIMILAR LOW PLACEMENT SUN NIGHT/EARLY MON. WILL GO GENERALLY WITH GFS/GFS ENSEMBLE TIMING WITH SOME NUDGING TO ECMWF AND CANADIAN AS INDICATED BY HPC. GALE CONDITIONS OVER THE W GULF ON SUN STILL LOOK GOOD WITH THE ENSEMBLE MEAN NOW SHOWING UP TO AN 80% CHANCE. SLIGHT CHANGES ARE STILL POSSIBLE OVER THE NEXT FEW DAYS AS THE FORECAST TIMING COMES INTO FOCUS. SW N ATLC... A BACK-DOOR COLD FRONT MOVED INTO THE AREA FROM THE N OVERNIGHT AND NOW EXTENDS FROM 29N65W W/NW TO THE N FLORIDA COAST. THE PRES GRADIENT IS INCREASING OVER THE ZONE WITH WINDS INCREASING TO 20-25 KT OVER MUCH OF THE AREA. SEAS WILL NOT BUILD TOO MUCH BEHIND THE FRONT DUE TO SHORT DURATION AND QUICKLY VEERING WINDS CAUSING SMALLER FETCHES. SEAS ARE STILL LIKELY TO BUILD TO 10 FT NEAR THE BAHAMAS E COAST DUE TO A MORE PROLONGED ELY WIND EVENT. WINDS VEER TO SE/S OVER THE W PART FRI AND SAT AS THE HIGH TO THE N SHIFTS E. A COLD FRONT EASES OFF THE SE U.S. COAST ON SUN BUT MAKES VERY LITTLE SEWD PROGRESS AS ATTACHED LOW PRES DEVELOPS OVER THE GULF OF MEXICO. THE LOW THEN LIFTS NE TO NEAR THE CAROLINA COAST ON MON WITH WINDS N OF THE BAHAMAS INCREASING AND VEERING TO THE W. CARIBBEAN AND TROPICAL N ATLC... MAINLY LIGHT EASTERLY TRADES OVER THE AREA WILL INCREASE MAINLY OVER THE CENTRAL CARIBBEAN BEGINNING TONIGHT AS HIGH PRES BUILDS N OF THE AREA. WINDS WILL LIKELY INCREASE TO 30 KT ALONG THE COLOMBIAN COAST BY FRI. WINDS ALSO BEGIN TO INCREASE OVER THE E CARIBBEAN AND TROPICAL ATLC WATERS FRI AS THE ATLC HIGH SHIFTS E. DOWN THE ROAD...THE COLD FRONT WHICH IS EXPECTED TO SWING ACROSS THE GULF OF MEXICO MAY ENTER THE FAR NW PART OF THE CARIBBEAN ON MON WITH INCREASING WINDS FROM THE YUCATAN CHANNEL SWD BY MON NIGHT. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER BERG