000 AGXX40 KNHC 181958 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EST SAT DEC 18 2010 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... COLD FRONT HAS BEGUN TO MOVE SE TODAY...AT ABOUT 15 KT...WITH LOW ACROSS THE ERN GULF NOW CLEARLY OUT AHEAD OF THE FRONT AND WITH WEAK TROFFING EXTENDING FROM THIS LOW SW TO THE N CENTRAL BAY OF CAMPECHE. A 1552 UTC ASCAT PASS REVEALED N-NW WINDS TO 25 KT ALONG THE MEXICAN COAST BEHIND THE FRONT...WHERE SEAS WILL BUILD TO 8-9 FT BY THIS EVENING. LOW IS EXPECTED TO MOVE E ACROSS FLORIDA AND EXIT INTO THE ATLC EARLY SUN THEN BEGIN TO ACCELERATE NE DURING THE DAY...WHILE THE ASSOCIATED PRE FRONTAL TROUGH SWEEPS THROUGH THE BASIN OVERNIGHT...WITH NW FLOW AROUND 15 KT BETWEEN THE TROUGH AND THE APPROACHING FRONT. NLY FLOW OF 15 TO 20 KT IS GENERALLY EXPECTED BEHIND THE FRONT...EXCEPT ALONG THE MEXICAN COASTAL ZONES...WITH SEAS REMAINING AOB 7 FT THROUGH SUN MORNING. FRONT WILL CLEAR THE BASIN BY MON MORNING WITH A HIGH OVER THE ERN SEABOARD THEN RIDGING SW INTO THE GULF AND ALLOWING FOR SLY RETURN FLOW TO SET UP W PORTIONS BY MON MORNING AND INCREASING TO NEAR 20 KT W OF 96W BY MON AFTERNOON. A NEXT COLD FRONT IS FORECAST TO MOVE INTO THE GULF COAST STATES TUE NIGHT-WED BUT ZONAL FLOW ALOFT LIFTS OUT SUPPORTING ENERGY AND DOES NOT ALLOW FOR FROPA INTO THE GULF UNTIL NEXT FRONT FRI MORNING. FRESH NW FLOW BEHIND THIS FRONT AT 20-25 KT WILL ENCOMPASS ENTIRE BASIN BY SAT MORNING...WITH WINDS TO 30 KT LIKELY ALONG THE MEXICAN COAST. SW N ATLC S OF 31N W OF 55W... 1021 MB HIGH NEAR 27N67W WILL SHIFT E NEXT 24 HOURS AS COMPLEX SERIES OF BOUNDARIES MOVE INTO AND ACROSS THE REGION. MODELS STILL NOT IN COMPLETE AGREEMENT ON HANDLING OF THIS SCENARIO AS THERE IS A LLVL VORTEX NE OF THE LITTLE CAYMANS MOVING NE INTO S COASTAL CUBA...THAT THE ECMWF KEYS ON...WHILE THE LOW IN THE E GULF IS THE FOCUS OF CYCLOGENESIS BY THE GFS AND UKMET. THESE LOWS AND ASSOCIATED TROFFING DRAGGING S AND SW WILL MOVE E AND NE ACROSS THE AREA AHEAD OF THE FRONT TONIGHT THROUGH SUN NIGHT...WITH SLY FLOW E OF THIS MAIN TROUGH INCREASING SUN TO NEAR GALE BY AFTERNOON AND TO GALE FORCE N OF 26N BY LATE AFTERNOON OR EVENING. SHOULD SIGNIFICANT DEVELOPMENT OF EITHER OF THESE LOWS OCCUR...GALE COULD BE SEEN IN THE ERN SEMICIRCLE AS EARLY AS SUN MORNING. AS FRONT SWEEPS ACROSS THE AREA BEHIND THIS COMPLEX SCENARIO SUN THROUGH MON NIGHT...LOW BOMBS OUT ACROSS THE WRN ATLC OFF OF HATTERAS AND DELMARVA...WITH MODELS SUGGESTING WLY GALES ALONG OUR NRN BOUNDARY MON NIGHT THROUGH TUE NIGHT. LARGE NW SWELL WILL BE GENERATED BY THIS LOW. CARIBBEAN AND TROPICAL N ATLC W OF 55W... REMNANTS OF OLD FRONT NOW IN THE SE CARIB ALONG 12N ARCHES NW TO JUST E OF THE LLVL VORT MOVING INTO SE CUBA...WITH PRES GRADIENT STILL YIELDING 20-25 KT OF NE TO E FLOW ACROSS THE ERN CARIB...AND HIGHEST SEAS AROUND 11 FT S OF HISPANIOLA. PERSISTENT TROUGH EXTENDS FROM COLOMBIA LOW TO JAMAICA...WITH MILD NW TO NLY FLOW TO ITS W. LONG PERIOD NWLY SWELL HAS BEGUN TO SUBSIDE ACROSS THE REGIONAL ATLC WATERS AND CARIB PASSAGES...WITH WWIII 1-3 FT HIGH ACROSS THIS REGION THIS MORNING COMPARED TO OBS. GULFMEX FRONT WILL PUSH TROUGH ASSOCIATED WITH LLVL VORT BACK TOWARDS THE E NEXT FEW DAYS...WITH PRE FRONTAL TROUGH ACROSS THE SW N ATLC REACHING MONA PASSAGE LATE MON MORNING...AS WEAK FRONT MOVES THROUGH YUCATAN CHANNEL TO NEAR 20N. FRONT WILL THEN BECOME STRUNG OUT AND SINK JUST SLIGHTLY S THROUGH TUE MORNING...AS HIGH PRES BUILDS ACROSS W PORTIONS OF THE BASIN AND INCREASES NE TRADES TO 20 KT...AND 20-25 KT THROUGH THE WINDWARD PASSAGE. WARNINGS.. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING