000 AGXX40 KNHC 090746 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 230 AM EST FRI JAN 09 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... 1017 MB SURFACE HIGH PRES IS CENTERED NEAR 27N88W...MAINTAINING GENERALLY LIGHT TO MODERATE FLOW ACROSS THE AREA. SOUTHERLY RETURN FLOW INCREASES OVER THE FAR WESTERN GULF LATER TODAY...AS THE HIGH PRES SHIFT EAST AHEAD OF A STRONG COLD FRONT MOVING THROUGH THE SOUTHERN PLAINS. THE FRONT MOVES OFF THE TEXAS COAST SAT MORNING...FOLLOWED BY STRONG NORTHERLY WINDS. THE UPPER SUPPORT FOR THE FRONT LIFTS OUT TO THE GREAT LAKES FRI INTO SAT...ALLOWING THE FRONT TO WEAKENS SOMEWHAT AS IT PUSHES INTO THE SOUTHEAST GULF WATERS. MEANWHILE SHORT WAVE ENERGY ALOFT DIGGING THROUGH THE ROCKIES INTO THE SOUTHERN PLAINS PROVIDES IMPETUS FOR A REINFORCING SHOT OF COLD AIR INTO THE NORTHWEST GULF...WITH HIGH PRES OF UP TO 1030 MB BUILDING BEHIND THE FRONT OVER TEXAS. THE MAIN FORECAST ISSUE REMAINS THE PROBABILITY OF GALE CONDITIONS OVER THE FAR WESTERN GULF SATURDAY NIGHT INTO SUNDAY. GIVEN THE TIGHT PRES GRADIENT AND GOOD COLD AIR ADVECTION FUNNELING ALONG THE MEXICAN COAST THIS STILL WARRANTS MENTION IN THE FORECAST AND NO CHANGES ARE PLANNED. WINDS AND SEAS DIMINISH STARTING LATE SUN THROUGH TUE AS HIGH PRES BUILDS ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEASTERN STATES. FORECASTER CHRISTENSEN CARIBBEAN... TRADE WIND FLOW REGIME WILL INTENSIFY ACROSS THE CARIBBEAN REGION THROUGH THIS WEEKEND AS SURFACE HIGH PRESSURE SLIDES SOUTHEASTWARD ACROSS THE CENTRAL N ATLC. CORRESPONDINGLY...NE TO E WINDS WILL INCREASE TO 20 TO 30 KT ACROSS A LARGE PART OF THE CARIBBEAN. THE STRONGEST WINDS ARE EXPECTED NEAR THE COAST OF COLOMBIA...WHERE OCCASIONAL GALES WILL BE POSSIBLE. A COUPLE WEAKENING FRONTS COULD APPROACH THE N CARIBBEAN THROUGH THE WEEKEND...BUT WILL PROVIDE NOTHING MORE THAN SLIGHTLY DRIER AND COOLER AIR...ALONG WITH MORE NORTHERLY WINDS. THE INCREASING WINDS WILL RESULT IN BUILDING SEAS. WAVEWATCH GUIDANCE INDICATES SEAS BUILDING TO 8 TO 12 FT BY SUNDAY ACROSS A LARGE PART OF THE S CARIBBEAN...WITH SEAS UP TO 13 FT NEAR THE COAST OF COLOMBIA. SW N ATLC... A PROGRESSIVE UPPER PATTERN WILL PERSIST FOR THE NEXT SEVERAL DAYS...WITH A LONGWAVE UPPER TROUGH CURRENTLY OVER THE W ATLC AND E CONUS. AN UPPER RIDGE WILL BUILD ACROSS THE REGION... FOLLOWED BY ANOTHER UPPER TROUGH FOR EARLY NEXT WEEK. WITH THIS PROGRESSIVE PATTERN IN PLACE...A SERIES OF FRONTS WILL CONTINUE TO TRAVERSE THE FORECAST AREA THROUGH NEXT WEEK. THE EASTERNMOST OF THESE FRONTS EXTENDS FROM 31N64W TO 22N79W AND CONTINUES TO WEAKEN AND SLOW ITS PROGRESS AS THE BULK OF THE UPPER LEVEL ENERGY LIFTS NORTH OF THE AREA. THE THREAT FOR GALE FORCE WINDS AHEAD OF THIS COLD FRONT HAS SUBSIDED AS THE STRONGER FLOW ALOFT LIFTS NORTH OF THE AREA...WITH SCATTEROMETER DATA PRESENTLY INDICATING SW WINDS UP TO 20 KT E OF THIS FRONT. GFS APPEARS TO OVERFORECAST WIND SPEEDS AHEAD OF THIS FRONT...POTENTIALLY IN RESPONSE TO WEAKER LOW LEVEL MIXING REALIZED E OF THE FRONT. W OF THIS FRONT...A SECONDARY COLD FRONT CONTINUES TO EMERGE OFF THE GEORGIA AND N FLORIDA COAST. THE COLD AIR ADVECTION IN THE WAKE OF THE PREVIOUS FRONT IS STEEPENING LOW LEVEL LAPSE RATES OVER THE RELATIVELY WARMER ATLANTIC WATERS...RESULTING IN STRONGER SOUTHWESTERLY WINDS E OF THE SECONDARY FRONT. SCATTEROMETER DATA AND SHIP REPORTS DEPICT THE BEST CHANCES FOR GALE FORCE WINDS TO BE OCCURRING NORTH OF THE FORECAST AREA. HOWEVER...GIVEN THE RAPID NE MOTION OF THE ATTENDANT SURFACE LOW N OF THE AREA...THE PRESSURE GRADIENT NEAR THIS SECOND FRONT WILL CONTINUE TO SLACKEN...WITH THE THREAT FOR GALE FORCE WINDS QUICKLY DIMINISHING TONIGHT. THIS SECONDARY FRONT IS FORECAST TO OVERTAKE THE PREVIOUS FRONT THIS WEEKEND...WITH A SURFACE HIGH DEVELOPING OFF THE SOUTH CAROLINA COAST THIS WEEKEND. ENSEMBLE MODEL GUIDANCE DEPICTS VERY LOW PROBABILITIES OF GALE FORCE WINDS ACROSS THE SW N ATLC THROUGH THE FORECAST PERIOD...THUS ALL GALE WARNINGS HAVE BEEN CANCELLED. SEAS OF 8 TO 12 FT ASSOCIATED WITH THE FRONTS N OF 29N WILL DIMINISH AS THE FRONTS WEAKEN TODAY...THOUGH ANOTHER SURGE OF 8 TO 15 FT SEAS IN N SWELL WILL AFFECT N PORTIONS OF THE REGION ON SAT. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER COHEN. TROPICAL PREDICTION CENTER.