000 AGXX40 KNHC 270812 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 312 AM EST THU NOV 27 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. RADIOFAX SCHEDULE FOR GRAPHICAL WIND WAVE...SURFACE FORECAST AND PEAK WAVE PERIOD CHARTS HAS CHANGED. FOR THE ATLANTIC BASIN THIS INCLUDES 24...36...48 AND 72 HOUR WIND WAVE..24...48..72 HOUR SURFACE FORECAST AND 48 AND 72 HOUR PEAK WAVE PERIOD CHARTS. FOR ADDITIONAL INFORMATION PLEASE REFER TO THE FAX SCHEDULE ON THE NHC WEB SITE AT HTTP://WWW.NHC.NOAA.GOV/RADIOFAX.SHTML THE GULF OF MEXICO... 10 TO 15 KT WINDS ARE FORECAST WEST OF 90W...AND 10 KT OR LESS ARE EXPECTED EAST OF 90W UNTIL LATE FRIDAY/EARLY SATURDAY WHEN A COLD FRONT SUPPOSEDLY WILL REACH THE NORTHWESTERN GULF COASTAL SECTIONS. THE FASTEST WINDS INITIALLY WILL BE IN THE SOUTHWESTERN CORNER...15 KT TO 20 KT...AND 10 KT TO 15 KT IN THE NORTHWESTERN CORNER. LIGHT WINDS STILL WILL BE EAST OF 90W. THE COLD FRONT STARTS TO MOVE ACROSS THE GULF OF MEXICO...THANKS TO A DEEP LAYER TROUGH THAT IS BEING FORECAST BY ALL THE GLOBAL MODELS. THIS FRONT WILL STALL ACROSS THE NORTHERN GULF ON SATURDAY BEFORE THE GFS MODEL FORECASTS WINDS THAT RANGE AT LEAST FROM 20 KT TO 25 KT EVERYWHERE. THAT REMAINS TO BE SEEN. ALL THE GLOBAL MODELS FORECAST A DEEP LAYER TROUGH TO MOVE INTO THE AREA AND TO STAY HERE BEYOND MONDAY. WHAT IS UNKNOWN IS EXACTLY THE STRENGTH OF THIS TROUGH...HOW DEEP IT WILL BECOME... AND IF IT WILL BE CENTERED AS COMPARATIVELY FAR TO THE SOUTH AS THE GFS FORECASTS IT TO BE...MORE TO THE SOUTH THAN THE OTHER MODELS. THE CARIBBEAN SEA AND TROPICAL NORTH ATLANTIC OCEAN... THE WINDS WILL RANGE FROM 10 KT TO 15 KT UNTIL LATE FRIDAY. EXPECT A BAND OF 20 KT WINDS TO BE ALONG A NORTHEAST-TO- SOUTHWEST LINE RIGHT THROUGH THE MIDDLE OF BOTH AREAS...EAST OF 70W. THE ARRIVAL OF THE GULF OF MEXICO COLD FRONT AND DEEP LAYER TROUGH ON EARLY MONDAY NIGHT MEANS 20 KT WINDS NEARLY EVERYWHERE WEST OF 70W. THE STRENGTH OF THE COLD FRONT WILL DEPEND ON THE FINAL UNKNOWN STRENGTH OF THE DEEP LAYER TROUGH THAT WILL STRETCH ACROSS THE U.S.A. LONG PERIOD NORTHERLY SWELL IS THE MAIN ITEM OF INTEREST OVER THE TROPICAL N ATLC WATERS AND E CARIBBEAN PASSAGES. THE WW3 MODEL DATA IS RUMORED TO BE A FEW FT TOO HIGH IN ITS SHORT TERM FORECAST AS COMPARED TO CURRENT BUOY AND SHIP OBS. I WILL TAKE THIS HIGH MODEL BIAS INTO ACCOUNT WHEN PREPARING OFF AND HSF PRODUCTS. THE SW N ATLC... A COLD FRONT IS WEAKENING ACROSS THE CENTRAL PORTION OF THE WATERS FROM 31N62W TO 25N67W TO THE BAHAMAS NEAR 22N72W. BUOY AND SHIP OBS SUGGEST THAT MOST OF THE WIND SPEEDS ARE LESS THAN 20 KT ON BOTH SIDES OF THE FRONT. THE WIND SPEEDS SHOULD REMAIN OF LITTLE CONCERN TO MARINERS UNTIL SATURDAY MORNING AS THE GULF OF MEXICO FRONTAL BOUNDARY MAKES ITS WAY EASTWARD. THE GFS MODEL WINDS EXPLODE WITH WIND SPEEDS OF 20 KT AND FASTER EVERYWHERE WEST OF 69W ON SUNDAY AFTERNOON. THAT REMAINS TO BE SEEN ALSO. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER MT. TROPICAL PREDICTION CENTER.