000 AGXX40 KNHC 202035 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 430 PM EDT WED MAY 20 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO AND SW N ATLC... THE PRESSURE GRADIENT BETWEEN A SLOW MOVING 1007 MB LOW NEAR 25N83W AND A 1032 MB HIGH OVER VIRGINIA IS PRODUCING A LARGE AREA OF STRONG NE WINDS OVER THE N GULF AND W ATLC. A HI-RES QSCAT PASS AROUND 11 UTC CONFIRMED THE GALE WARNING...WITH MAX WINDS ESTIMATED IN THE 35-40 KT RANGE...IN BOTH THE E GULF AND SW N ATLC. STATION SG0F1 AT 35 M HEIGHT HAS BEEN REPORTING WINDS NEAR 40 KT WITH HIGHER GUSTS. S TO SW WINDS HAVE INCREASED TO 20-25 KT OVER THE S SEMICIRCLE OF THE LOW. SEAS ARE HIGHEST...16-18 FT...OFF THE NE FLORIDA COAST DUE TO THE EXTENSIVE FETCH... DURATION AND ASSOCIATED E SWELL. MAX SEAS OBSERVED IN THE GULF ARE NEAR 12 FT. MODELS ARE IN GOOD AGREEMENT IN SHOWING THIS LOW DRIFT W THROUGH THE MIDDLE GULF INTO FRI THEN TRACK NWD AND INLAND OVER LOUISIANA THIS WEEKEND. AS THE LOW TRACKS W...GALES ARE EXPECTED TO SPREAD INTO THE N MIDDLE WATERS SHORTLY. WHILE THE LOW IS EXPECTED TO STAY NEARLY STEADY-STATE...WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY THU MORNING AS THE HIGH OVER VIRGINIA SHIFTS E AND WEAKENS...ALLOWING THE GRADIENT TO SLACKEN. OTHER AREA OF INTEREST IS A LARGE AREA OF CONVECTION OVER THE SE BAHAMAS AND ADJACENT AREAS...FUELED BY UPPER DIFFLUENCE E OF THE NEARLY STACKED LOW OVER THE E GULF. CONVECTIVE PROCESSES AND FORCING FROM THE TAIL END OF A SHEAR AXIS IN THE AREA...WILL LIKELY FORM A SFC TROUGH IN THAT AREA TONIGHT OR THU. MODELS ARE IN SOME AGREEMENT IN SHOWING BROAD TROUGHING...GFS BEING THE MOST AGGRESSIVE IN DEPICTING A CLOSED LOW. PREVIOUS FORECAST LOOKS GOOD...LEANING TOWARD THE ECMWF...IN SHOWING 20-25 KT E TO SE FLOW DEVELOPING NEAR THE TROUGH AXIS WITH SEAS INCREASING UP TO 10 FT. CARIBBEAN AND TROPICAL ATLC... SFC OBSERVATIONS AND SCATTEROMETER DATA SHOWS E TO SE 15-20 KT TRADES OVER MUCH OF THE E CARIBBEAN AND THE S PORTION OF THE TROPICAL N ATLC. E TO SE 10-15 KT FLOW EXISTS ACROSS THE REMAINDER OF THE TROP N ATLC. VARIABLE WINDS ARE EVEN LIGHTER OVER MUCH OF THE W CARIBBEAN DUE TO THE TRAILING TROUGH EXTENDING S FROM THE LOW OVER THE E GULF. LITTLE CHANGE IS EXPECTED THROUGH SAT AS THE PATTERN HOLDS. BY SUN...E FLOW WILL BECOME REESTABLISHED OVER THE W CARIBBEAN AS THE TROUGH SHIFTS N OF THE AREA. OTHERWISE...CONTINUED WIND/SEAS INTO EARLY NEXT WEEK ACROSS OTHER ZONES. WARNINGS ATLC... .GALE WARNING N OF 28N W OF 76W...AMZ080. CARIBBEAN... .NONE. GULF OF MEXICO... .GALE WARNING N OF 27N E OF 90W...GMZ086 AND GMZ084.. FORECASTER CANGIALOSI. TROPICAL PREDICTION CENTER.