000 AGXX40 KNHC 190658 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 258 AM EDT SUN AUG 19 2012 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... HELENE HAS BECOME POST-TROPICAL/A REMNANT LOW OVER MEXICO WITH ASSOCIATED CONVECTION CONTINUING TO DECREASE ALTHOUGH LOCALLY HEAVY RAINFALL WILL REMAIN POSSIBLE THROUGH THE REST OF TODAY. THE LAST SEVERAL RUNS OF THE GFS HAVE BACKED OFF WITH REGARD TO MOVING THE REMNANTS OF THE CIRCULATION BACK OVER THE GULF WITH REGENERATION. OTHERWISE A WEAK EXTENSION OF ATLC RIDGING IS SETTLED ACROSS 26N/27N WITH LIGHT TO MODERATE WINDS AND SEAS DOMINATING THE GULF WATERS. WEAK LOW TO MID LEVEL TROUGHS WILL CONTINUE TO ROTATE THROUGH THE NORTHERN GULF WATERS HELPING TO SPARK CONVECTION THERE FOR THE NEXT SEVERAL DAYS. A WEAK COLD FRONT IS EXPECTED TO ENTER THE FAR NW GULF LATE TONIGHT INTO EARLY MON REACHING FROM SOUTHERN LOUISIANA TO NEAR THE TEXAS MEXICO BORDER BY MON EVENING WHERE IT WILL LIKELY STALL OUT AND BECOME ILL DEFINED THROUGH THE REMAINDER OF THE WEEK. THE NORTHERN PORTION OF A TROPICAL WAVE MAY CLIP THE SOUTHERN GULF FROM THE NW CARIBBEAN TUE THROUGH WED...MOVING INTO MEXICO LATE WED. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TROPICAL WAVE REACHING FROM EASTERN JAMAICA TO THE SW CARIBBEAN WILL CONTINUE TO THE W-NW APPROACHING THE YUCATAN PENINSULA LATE MON INTO TUE. ATLC RIDGING WILL BUILD NE OF THE AREA EARLY IN THE WEEK AND THAT COMBINED WITH A LIFTING OF THE MONSOON TROUGH INTO THE SW CARIBBEAN WILL RESULT IN FRESH TO STRONG EASTERLY TRADES ACROSS THE CENTRAL CARIBBEAN LATE SUN NIGHT INTO MON SPREADING INTO THE W CARIBBEAN BY EARLY TUE INTO WED...INCLUDING THE GULF OF HONDURAS. ANOTHER TROPICAL WAVE CURRENTLY ALONG 47W WILL MOVE INTO THE TROPICAL N ATLC WATERS MON AND INTO THE CARIBBEAN TUE AND WED WHILE BECOMING LESS DEFINED AT THE SURFACE. ATTENTION THEN WILL FOCUS ON AN AREA OF LOW PRES CURRENTLY NEAR 14.5N35W WITH AN ATTENDANT TROPICAL WAVE. THIS LOW HAS A HIGH CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AND THE GFS AND ECMWF BOTH TAKE THE LOW ACROSS THE TROPICAL N ATLC AND E CARIBBEAN THE THROUGH THU. THE GFS SOLUTION HAS TRENDED DOWNWARD WHILE THE ECMWF HAS TRENDED UPWARD...WITH THE ECMWF STILL WEAKER THAN THE GFS. INTERESTS IN THE E CARIBBEAN SHOULD CONTINUE TO MONITOR ANY DEVELOPMENTS OF THIS LOW THROUGH THE WEEK. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... SEMI-PERMANENT SUBTROPICAL HIGH PRES CENTERED NEAR 27N57W WITH A RIDGE EXTENDING WESTWARD ALONG 27N TO EASTERN FLORIDA WILL SLOWLY SHIFT W THROUGH WED. A TROPICAL WAVE S OF 22N OVER EASTERN CUBA WILL MOVE RAPIDLY ACROSS THE GREATER ANTILLES... WITH THE MAJORITY OF ANY ASSOCIATED IMPACTS REMAINING S OF THE AREA. LIGHT TO MODERATE WINDS AND 3-5 FT SEAS WILL DOMINATE THE SW N ATLC ZONES THROUGH EARLY WEEK...WITH WINDS LOCALLY TO 20 KT S OF 22N AND SEAS 1-3 FT W OF THE BAHAMAS. THE HIGH WEAKENS WED AND THU PERHAPS ALLOWING FOR A DEVELOPING AREA OF LOW PRES WELL SE OF THE AREA CURRENTLY TO SNEAK INTO THE SE ZONES TUE AND THU. A BLEND OF THE ECMWF AND GFS WAS USED FOR THE OFFSHORE WATERS FOR THIS FORECAST PACKAGE. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER LEWITSKY