000 AGXX40 KNHC 111815 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 215 PM EDT THU AUG 11 2011 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A WEAK RIDGE OF HIGH PRESSURE WILL PREVAIL ACROSS THE GULF OF MEXICO THROUGH THE FORECAST PERIOD. LATEST OBSERVATIONS INDICATE LIGHT TO MODERATE WINDS ACROSS THE GULF WITH SEAS GENERALLY 1 TO 3 FT. WITH THE RIDGE PREVAILING THROUGH THE FORECAST PERIOD...THESE GENERAL CONDITIONS ARE EXPECTED TO CONTINUE. THE EXCEPTION IS FRESH WINDS W OF THE YUCATAN PENINSULA EACH EVENING/NIGHT DUE TO DIURNALLY DRIVEN LOCAL EFFECTS. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TROPICAL WAVE OVER THE CENTRAL CARIBBEAN WATERS WILL SHIFT WESTWARD AND FINALLY W OF THE AREA SAT NIGHT WHERE IT WILL DISSIPATE. THIS WAVE WILL NOT HAVE A SIGNIFICANT AFFECT ON THE WINDS ACROSS THE CARIBBEAN THROUGH THIS PERIOD. THE PRIMARY AFFECT ON WINDS OVER THE CARIBBEAN IS DUE TO THE PRESSURE GRADIENT BETWEEN THE RIDGE OVER THE SW N ATLC AND LOWER PRESSURE OVER SOUTH AMERICA. THIS WILL MAINTAIN FRESH TO STRONG TRADES MAINLY OVER THE CENTRAL CARIBBEAN THROUGH THE FIRST HALF OF THE WEEKEND. THE TRADES ARE EXPECTED TO DIMINISH AS THE RIDGE OVER THE SW N ATLC WEAKENS WITH A SURFACE LOW...POSSIBLE TROPICAL CYCLONE EXPECTED TO SHIFT INTO THE AREA EARLY NEXT WEEK. THIS WILL LOOSEN THE PRESSURE GRADIENT OVER THE CARIBBEAN WITH MODERATE TO FRESH TRADES PREVAILING. LOW PRESSURE CURRENTLY EMBEDDED IN THE MONSOON TROUGH WILL MOVE INTO THE CENTRAL TROPICAL N ATLC WATERS LATE SAT INTO EARLY SUN. THIS LOW MAY DEVELOP INTO A POSSIBLE TROPICAL CYCLONE. THERE REMAINS DISAGREEMENT BETWEEN THE GFS/ECMWF WITH REGARD TO THE LOW WITH THE GFS BEING A BIT MORE AGGRESSIVE WITH ITS FURTHER DEVELOPMENT. WINDS ASSOCIATED TO THIS FEATURE WILL INCREASE TO 20-25 KT OVER THE NORTHERN PORTION OF THE BASIN. THE LOW IS CURRENTLY FORECAST TO EXIT THE AREA AND MOVE INTO THE SW N ATLC LATE MON. A SECOND AREA OF LOW PRESSURE WILL APPROACH THE TROPICAL N ATLC BY MID WEEK. INTERESTS IN THE E CARIBBEAN SHOULD CONTINUE TO MONITOR THE PROGRESS OF BOTH OF THESE DISTURBANCES DURING THE NEXT WEEK. SOUTHWEST N ATLC... A 1018 MB HIGH PRES IS POSITIONED NEAR 25N62W WITH A RIDGE EXTENDING TO THE CENTRAL BAHAMAS. A PAIR OF TROUGHS ARE OVER THE NW PORTION OF THE AREA GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS. THIS TROUGHING WILL LINGER OVER THE SAME GENERAL AREA THROUGH SAT BRINGING ADDITIONAL RAINFALL TO FLORIDA...CUBA AND THE WESTERN BAHAMAS. THE HIGH WILL HOLD NEARLY STATIONARY THROUGH EARLY SAT BEFORE DRIFTING TO THE NW-N LATE SAT THROUGH MON. WITH THIS SCENARIO...EXPECT LIGHT TO MODERATE WINDS AND FAIRLY TRANQUIL SEAS THROUGH THE WEEKEND. AN AREA OF LOW PRES...A POSSIBLE TROPICAL CYCLONE... MAY ENTER THE SE PORTION SUN NIGHT THROUGH MON. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AL