000 AGXX40 KNHC 181825 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EDT SAT AUG 18 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... WESTERN EXTENSION OF ATLC RIDGE ALONG 27N REACHES FROM CENTRAL FLORIDA TO SOUTHERN TEXAS. LIGHT TO MODERATE ANTICYCLONIC FLOW PREVAILS ACROSS MOST OF THE GULF. TROPICAL DEPRESSION HELENE CONTINUES TO WEAKEN OVER SOUTHERN MEXICO...WITH SCATTERED SHOWERS AND TSTMS LOCATED E OF THE CENTER OVER THE SW GULF. A WEAK COLD FRONT WILL ENTER THE NW GULF MON...AND DRIFT SLOWLY EASTWARD ACROSS THE NORTHERN GULF THROUGH WED. A BLEND OF THE GFS AND ECMWF WAS USED FOR THE FRONTAL POSITION. A BROAD AREA OF LOW PRES IS EXPECTED TO PERSIST OVER THE NW GULF MON THROUGH THU. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TROPICAL WAVE ALONG 69W IS MOVING RAPIDLY WESTWARD ACROSS THE CARIBBEAN. IT IS EXPECTED TO MOVE INTO THE WESTERN CARIBBEAN BY MON. HIGH PRES RIDGE N OF THE AREA ALONG 27N WILL SUPPORT FRESH WINDS ACROSS THE CARIBBEAN THROUGH MON WITH E WINDS INCREASING TO 20-25 KT IN THE CENTRAL CARIBBEAN TUE AND WED AS THE PRESSURE GRADIENT BECOMES TIGHTER N OF CUBA. ESE WINDS WILL ALSO PICK UP IN THE GULF OF HONDURAS EARLY NEXT WEEK...WITH SEAS BUILDING TO AROUND 6 FT. ANOTHER TROPICAL WAVE IN THE CENTRAL ATLC ALONG 42W IS EXPECTED TO MOVE INTO THE TROPICAL N ATLC TUE...FOLLOWED BY A STRONGER AREA OF LOW PRES ASSOCIATED WITH A TROPICAL WAVE ALONG 27W EXPECTED TO INTENSIFY...AND COULD BE A TROPICAL CYCLONE AS IT REACHES THE TROPICAL N ATLC WED AND APPROACHES THE WINDWARD ISLANDS ON THU. THE GFS IS VERY AGGRESSIVE DEVELOPING THE SECOND WAVE NEAR 27W WHILE THE ECMWF MODEL IS MUCH WEAKER...MAINTAINING THE SYSTEM AS A STRONG WAVE. THE UKMET IS THE PREFERRED SOLUTION IN BOTH INTENSITY AND LOCATION...BETWEEN THE OTHER TWO EXTREMES. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... SEMI-PERMANENT SUBTROPICAL HIGH S OF BERMUDA WILL SLOWLY SHIFT W THROUGH WED...WITH A RIDGE EXTENDING WEST ALONG 27N TO S CENTRAL FLORIDA. A TROPICAL WAVE S OF 22N ALONG 69W WILL MOVE RAPIDLY ACROSS THE GREATER ANTILLES...HELPING TO ENHANCE WINDS S OF 23N. A SERIES OF WEAK TROUGHS WILL MOVE EASTWARD N OF 28N THROUGH EARLY NEXT WEEK. A TROPICAL WAVE AND ASSOCIATED LOW CENTERED NEAR 14N27N IS PROJECTED TO MOVE W AND REACH THE WINDWARD ISLANDS THU. 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 MUNDELL