000 AGXX40 KNHC 190729 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT SUN APR 19 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... RETURN FLOW AROUND A BROAD SURFACE RIDGE OVER THE E CONUS CONTINUES ACROSS A LARGE PART OF THE GULF REGION...WHICH IS BEING MAINTAINED BY A SURFACE HIGH DRIFTING SOUTHEASTWARD ACROSS THE W ATLC. THE QUIKSCAT PASS AROUND 19/0300 UTC INDICATES E TO SE WINDS OF 15 TO 20 KT ACROSS THE GULF REGION...WITH THE STRONGEST WINDS ACROSS THE S GULF. SHIPS ARE REPORTING UP TO 8 FT SEAS ACROSS THE GULF...CONSISTENT WITH WAVEWATCH GUIDANCE. THE AFOREMENTIONED SURFACE RIDGE IS ASSOCIATED WITH A WEAKENING DEEP LAYER RIDGE OVER THE SE CONUS. THIS RIDGE CONTINUES TO BREAK DOWN AS A MID/UPPER-LEVEL TROUGH OVER THE SOUTHERN PLAINS IS BEING EJECTED EASTWARD. A RELATIVELY WEAK FRONT IS FORECAST TO ENTER THE NW GULF BY MID-DAY TODAY. THE FRONT WILL BE INITIALLY FOLLOWED BY N WINDS OF 15 TO 20 KT...HIGHEST ALONG THE COAST OF MEXICO. MEANWHILE...A VIGOROUS SHORTWAVE TROUGH CURRENTLY OVER THE NORTHERN PLAINS CONTINUES DIVING SOUTHEASTWARD...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE E CONUS BY MONDAY...WITH A HIGH AMPLITUDE LONGWAVE UPPER RIDGE OVER THE WESTERN CONUS. STRONG SUBSIDENCE E OF THIS RIDGE WILL RESULT IN SURFACE PRESSURE RISES OVER S TEXAS AND E MEXICO MON AND TUE...WITH THE FRONT BECOMING REINFORCED DURING THIS TIME. NORTHERLY WINDS IN THE WAKE OF THE FRONT WILL INCREASE BY LATE MON INTO TUE...WITH THE FRONT CLEARING THE GULF BY LATE TUE. N WINDS OF 20 TO 25 KT WILL AFFECT A LARGE PART OF THE W GULF IN THE WAKE OF THE SECONDARY SURGE LATE MON...THOUGH THERE IS INCREASING CONCERN FOR STRONGER WINDS IN THE SW GULF...WHERE THE NEARBY TOPOGRAPHY IN MEXICO WILL ACT TO FUNNEL THE COLDER AIR SOUTHWARD. OPERATIONAL MODELS ARE INDICATING A RATHER STRONG SURFACE RIDGE IN THE WAKE OF THE FRONT. THE AIRMASS IN THE WAKE OF THE FRONT IS NOT PARTICULARLY COLD WHERE THE LOW LEVEL JET STRENGTH IS NOT EXPECTED TO EXCEED 34 KT. THESE FACTORS WILL LIKELY LIMIT THE POTENTIAL FOR STRONG LOW LEVEL MIXING AFTER THE SECONDARY SURGE. THUS...FORECAST NORTHERLY WINDS HAVE BEEN INCREASED TO 30 KT FOR LATE MON AND EARLY TUE S OF 22N W OF 93W. THE STRONGER POST FRONTAL WINDS WILL RAISE SEAS BACK TO 8 FT OVER THE SW GULF AFTER A BRIEF LULL PRIOR TO FRONTAL PASSAGE. SW N ATLC... A COLD FRONT EXTENDS FROM 31N53W TO HISPANIOLA...WITH A REINFORCING FRONT EXTENDING FROM A 1013 MB SURFACE LOW NEAR 30N57W TO 27N64W. MODEL GUIDANCE AND RECENT SCATTEROMETER DATA DATA INDICATE SW WINDS OF 20 TO 25 KT E OF THE INITIAL FRONT N OF 28N...WITH NE WINDS OF 20 TO 25 KT W OF THE REINFORCING FRONT TO 64W AND ACROSS THE BAHAMAS. THE REINFORCING FRONT IS FORECAST TO BECOME THE DOMINANT FRONT TODAY. SW WINDS E OF OF THIS FRONT WILL BE IN THE 20 TO 25 KT RANGE AS IT MOVES EASTWARD TODAY AND WEAKENS WHILE ENCOUNTERING A STRONGER SURFACE RIDGE OVER THE E ATLC. WAVE HEIGHTS UP TO 10 FT IN NE SWELL IN THE WAKE OF THE REINFORCING FRONT WILL CONTINUE IMPACTING MUCH OF THE SW NORTH ATLC TODAY...THOUGH MAXIMUM SEA HEIGHTS WILL CONTINUE SUBSIDING. IN THE WAKE OF THIS REINFORCING FRONT...SURFACE HIGH PRESSURE WILL BUILD OVER THE SW NORTH ATLC. THE NEXT FRONT...DISCUSSED IN THE GULF OF MEXICO SECTION ABOVE...WILL MOVE OFF THE SE GEORGIA COAST TUESDAY. SW WINDS OF 20 TO 30 WILL DEVELOP AHEAD OF THIS FRONT ACROSS THE W ATLC ON MONDAY...WITH GALES N OF THE DISCUSSION AREA...WHERE THE STRONGER PRESSURE GRADIENT WILL BE PRESENT. THE FRONT WILL BE FOLLOWED BY W WINDS GENERALLY LESS THAN 20 KT INTO EARLY NEXT WEEK. CARIBBEAN AND TROPICAL N ATLC... FRESH TRADE WINDS ARE FORECAST TO CONTINUE ACROSS THE REGION THROUGH EARLY NEXT WEEK...AS A RESULT OF PERSISTENT AND BROAD SURFACE RIDGING N OF THE DISCUSSION AREA. PERIODIC WEAKNESSES IN THIS RIDGING DUE TO FRONTAL PASSAGES N OF THE CARIBBEAN WILL KEEP THESE TRADES NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES THROUGH TUE. THE LATEST SCATTEROMETER AND SURFACE OBSERVATIONS INDICATE NE TO E WINDS OF 15 TO 20 KT ACROSS THE CARIBBEAN... HIGHEST NEAR THE COAST OF COLOMBIA AND THE GULF OF HONDURAS. ALSO...SURFACE HIGH PRESSURE OVER THE W ATLC IS RESULTING N TO NE WINDS UP TO 25 KT THROUGH THE WINDWARD PASSAGE. ALSO...LONG PERIOD NORTHERLY SWELL IS FORECAST TO CONTINUE SPREADING THROUGH THE E CARIBBEAN PASSAGES THROUGH MONDAY. EARLY NEXT WEEK...TRADES WILL INCREASE OVER THE E CARIBBEAN AND TROPICAL N ATLC AS SURFACE HIGH PRESSURE BUILDS OVER THE CENTRAL ATLC...THOUGH THEY WILL DECREASE OVER THE W CARIBBEAN WITH THE APPROACH OF THE GULF OF MEXICO COLD FRONT. THE STRONGEST WINDS...UP TO 30 KT WITH SEAS TO 11 FT...WILL BE FOUND NEAR THE COAST OF COLOMBIA. ATLC... .NONE.. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER COHEN. TROPICAL PREDICTION CENTER.