000 AGXX40 KNHC 112207 AAA MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 500 PM EST SAT DEC 11 2010 UPDATE FOR GALES IN THE GULF 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... AFTER EVALUATION OF 12Z GUIDANCE...HAVE DECIDED TO ISSUE GALE WARNING FOR NE GULF BEGINNING 18Z SUN...N OF 27N E OF 87W...WITH GFS SUGGESTING THAT GALES COULD OCCUR IMMEDIATELY AS FRONT ENTERS THE GULF WATERS 12-15Z. MODEL CONSENSUS OF 30M AND 1000 MB WINDS...CONSIDERING A VERY UNSTABLE BL AS COLD AIR MOVES OVER WARMER WATERS OF GULF...THAT LLVL FLOW WILL MIX DOWN. WE HAVE BEEN HESITANT...BUT EVEN NOGAPS IS SHOWING IT...SO I HAVE PULLED THE TRIGGER. WILL UPDATE OFFSHORE FORECAST ASAP. OTHERWISE... A STRONG COLD FRONT WILL MOVE OFF THE TEXAS COAST TONIGHT AND SWEEP RAPIDLY SE ACROSS THE GULF THROUGH SUN NIGHT. 25-30 KT WINDS WITH HIGHER GUSTS CAN BE EXPECTED NW OF THE FRONT THROUGH SUN. SCATTERED SHOWERS AND ISOLATED TSTMS ARE LIKELY ALONG THE FRONTAL BOUNDARY. WIND-DRIVEN SEAS WILL RAPIDLY BUILD BEHIND THE COLD FRONT...AND ARE EXPECTED TO REACH A PEAK OF 15-18 FT IN THE SE GULF MON. AHEAD OF THE FRONT THIS AFTERNOON 20 KT SOUTHERLY RETURN FLOW REMAINS IN PLACE OVER THE NW GULF...WITH LIGHT WINDS ASSOCIATED WITH A WEAKENING RIDGE IN THE REMAINDER OF THE GULF. BRIEF PERIOD OF GALE FORCE WINDS IS POSSIBLE IN THE NE GULF SUN NIGHT. LATEST SREF 34 KT WIND PROBABILITIES ARE ABOUT 30 PERCENT. HIGH PRES BUILDS IN BEHIND THE FRONT WITH WINDS DIMINISHING FROM W TO E ACROSS THE GULF MON AND TUE. RIDGING RETURNS ACROSS THE GULF WATERS TUE AND WED WITH SOUTHERLY FLOW AGAIN BECOMING ESTABLISHED OVER THE W GULF WATERS AHEAD OF THE NEXT COLD FRONT WHICH WILL APPROACH THE NW GULF THU. CARIBBEAN AND TROPICAL N ATLC S OF 22N W OF 55W... 1010 MB LOW PRES NEARLY STATIONARY OVER EASTERN PANAMA NEAR 09N77W WITH A SHEAR LINE EXTENDING N-NE FROM THE LOW TO HAITI. THE LOW WILL REMAIN NEARLY STATIONARY THROUGH SUN...WITH WINDS GRADUALLY DECREASING TO AROUND 15 KT AND SEAS SUBSIDING BELOW 8 FT. MODERATE TO FRESH TRADES OVER THE REMAINDER OF THE CARIBBEAN AND TROPICAL N ATLC. 8-11 FT NE SWELL ACROSS THE TROPICAL N ATLC. A STRONG COLD FRONT WILL REACH THE YUCATAN CHANNEL SUN NIGHT AND MOVE RAPIDLY SE...EXTENDING FROM JAMAICA TO CENTRAL PANAMA MON AND FROM PUERTO RICO TO NW COLOMBIA TUE...THEN STALL AND WEAKEN THROUGH WED. N WINDS OF 20-30 KT BEHIND THE FRONT WILL BUILD SEAS TO UP TO 14 FT ALONG THE COAST OF NICARAGUA AND COSTA RICA MON NIGHT. BY THE TIME THE FRONT ENTERS THE NW PORTION OF THE TROPICAL N ATLC TUE NIGHT WINDS WILL BE CONSIDERABLY WEAKER... BUT NW SWELL WILL BUILD SEAS TO 13 FT BEHIND THE BOUNDARY. SW N ATLC S OF 31N W OF 55W... SCATTEROMETER DATA THIS MORNING REVEALED WINDS ARE BEGINNING TO DIMINISH N OF A 1010 MB LOW NEAR 26N64W. THE LOW IS EXPECTED TO DISSIPATE TONIGHT. SW FLOW WILL RAPIDLY INCREASE OVER THE FAR NW WATERS LATE TONIGHT AHEAD OF A STRONG COLD FRONT. MODEL GUIDANCE HAS TRENDED STRONGER AHEAD OF THE FRONT WITH GFS ENSEMBLE 34 KT WIND PROBABILITIES NEAR 80 PERCENT. THE FRONT WILL REACH FROM NEAR 31N77W TO CENTRAL CUBA MON NIGHT AND FROM NEAR 31N73W TO EASTERN CUBA TUE...THEN PUSH E OF THE AREA TUE NIGHT. MODEL GUIDANCE INDICATES 25-35 KT W WINDS N OF 27N BEHIND THE FRONT SUN NIGHT THROUGH MON NIGHT OR TUE. SEAS WILL RAPIDLY BUILD TO 20-25 FT N OF 30N MON NIGHT AND TUE. WINDS WILL DIMINISH FROM W TO E TUE NIGHT THROUGH WED AS RIDGING BUILDS SE ACROSS THE AREA. WARNINGS... ATLC... .AMZ080...GALE WARNING N OF 28N WITHIN 180 NM E OF FRONT SUN AFTERNOON THROUGH MON. .AMZ080...GALE WARNING N OF 27N W OF FRONT SUN NIGHT THROUGH TUE. CARIBBEAN... .NONE. GULF OF MEXICO... .GALE WARNING GMZ084-086. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING/MUNDELL