000 AGXX40 KNHC 230638 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 240 AM EDT SAT MAY 23 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... MAIN ISSUE CONTINUES TO BE THE DEVELOPMENT AND TRACK OF A 1006 MB LOW PRES CENTERED APPROXIMATELY 110 NM SE OF THE MISSISSIPPI DELTA...NEAR 28.4N88.4W. A LARGE AREA OF CONVECTION IS NOTED ON IN THE NE QUADRANT OF THE LOW PRES. FURTHER DEVELOPMENT OF THE LOW IS POSSIBLE THROUGH TODAY AS IT MOVES NW TOWARD THE LOUISIANA AND MISSISSIPPI COASTS. REFER TO THE LATEST TWOAT TROPICAL CYCLONE OUTLOOK BULLETIN OR THE NHC WEB SITE FOR ADDITIONAL INFORMATION. GRADIENT FLOW OVER THE NE GULF REMAINS AROUND 20 KT OUT OF THE E TO SE WITH HIGHER GUSTS NEAR CONVECTION. OTHERWISE...GENERALLY LIGHT TO MODERATE FLOW PERSISTS AROUND THE LOW IN OTHER SECTORS OF THE GULF. WINDS AND SEAS WILL DIMINISH ACROSS THE GULF BY LATE TODAY AS THE LOW MOVES INLAND. A SURFACE RIDGE BUILDS ACROSS THE GULF FROM THE WESTERN ATLC ALONG GENERALLY 24N ON SUNDAY. SOUTHERLY RETURN FLOW STARTS TO INCREASE OVER THE FAR WESTERN GULF MON THROUGH MID WEEK. CARIBBEAN AND ATLC S OF 18N W OF 55W... THE PRESSURE GRADIENT REMAINS FAIRLY LOOSE OVER THE WESTERN CARIBBEAN...BETWEEN LOW PRESSURE OVER THE GULF OF MEXICO AND A TROPICAL WAVE EXITING WEST THROUGH COSTA RICA. DIVERGENCE ON THE RIGHT FRONT QUADRANT OF AN UPPER JET NOSING INTO THE WESTERN WILL MAINTAIN A BROAD SURFACE TROUGH OFF FROM ROUGHLY COLOMBIA TO JAMAICA THROUGH THE WEEKEND. THIS IN TURN WILL KEEP WINDS AND SEAS LIMITED. OVER THE EASTERN CARIBBEAN...THE GRADIENT REMAINS SLIGHTLY TIGHTER...TO THE SOUTH OF A SURFACE RIDGE EXTENDING FROM N OF BERMUDA TO THE NORTHERN BAHAMAS. QUIKSCAT DATA AND A SHIP OBSERVATION SHOWED 20 KT TRADE WIND FLOW OFF THE VENEZUELAN COAST. THE SURFACE RIDGING BUILDS THROUGH THE WEEKEND...ALLOWING THE AREA OF 20 KT WINDS TO EXPAND ACROSS MUCH OF THE EASTERN CARIBBEAN AS WELL AS THE TROPICAL ATLC WATERS E OF THE WINDWARDS TO 55W THROUGH THE MIDDLE OF NEXT WEEK. ATLANTIC WATERS N OF 18N W OF 55W... CURRENT BUOY OBSERVATIONS FROM BUOYS 41010 AND 41009 OFF THE EAST CENTRAL FLORIDA COAST SHOW 15 TO 20 KT E TO SE FLOW PERSISTING BETWEEN A 1025 MB SURFACE HIGH PRES CELL N OF BERMUDA AND A 1006 LOW PRESSURE ARE OVER THE N CENTRAL GULF. A 23Z QUIKSCAT PASS SHOWED 15 TO 20 KT FLOW THROUGH THE LENGTH OF THE BAHAMAS AS WELL. THE MAIN FORECAST ISSUE FOR THE NEXT SEVERAL DAYS WILL BE THE POTENTIAL DEVELOPMENT OF A SURFACE TROUGH OVER THE SOUTHERN BAHAMAS. AN UPPER TROUGH EXTENDS ACROSS THE GULF FROM TEXAS THROUGH SOUTH FLORIDA. DIVERGENT FLOW ALOFT ON THE SE EDGE OF THE UPPER TROUGH IS TO PROVIDE THE SUPPORT TO THE SURFACE TROUGH. THE GFS REMAINS THE MOST AGGRESSIVE...DEVELOPING A WEAK CLOSED CIRCULATION OVER THE NORTHERN BAHAMAS BY SUNDAY NIGHT. THE 23/00Z ECMWF SHOWS ONLY A WEAK TROUGH MON INTO TUE OVER THE NORTHERN BAHAMAS AND FLORIDA PENINSULA...WHILE THE UKMET DOES NOT SHOW ANY TROUGH AT ALL. AT ANY RATE...MODERATE TO FRESH E TO SE FLOW MAINLY W OF 70W WILL REMAIN IN PLACE THROUGH THE MIDDLE OF NEXT WEEK ON THE SW PERIPHERY OF THE RIDGE OVER THE CENTRAL ATLC. E OF 70W...A PERSISTENT TROUGH WILL REMAIN NE OF THE LEEWARDS THROUGH THE PERIOD. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER CHRISTENSEN. TROPICAL PREDICTION CENTER.