000 AGXX40 KNHC 070608 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 215 AM EDT TUE SEP 07 2010 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... TS HERMINE INLAND AND CONTINUING NW AT 12 KT. SE TO WINDS AT 20 TO 30 KT OVER WATERS W OF 90W. EXPECT WINDS TO DIMINISH TO 20 KT OVER WATER BY SUNSET TODAY AND FURTHER DIMINISH TO 15 KT WED AFTERNOON...AND MAINLY OVER WATERS N OF 21N W OF 93W. THEN LITTLE CHANGE IN WINDS THROUGH SAT. SEAS HEIGHTS ASSOCIATED WITH HERMINE WERE A MAX OF 21 FT AT LANDFALL...BUT ACCORDING TO BUOY OBS THIS WAS ONLY IN VERY SMALL AREA NEAR THE CENTER. BEST GUIDANCE INDICATES THAT THE SE SWELL SHOULD SUBSIDE TO 8-12 FT BY SUNSET TODAY OVER THE WATERS N OF 25N W OF 92W...AND BELOW 8 FT ALL WATERS BY SUNRISE WED. SW N ATLC... A BROAD TROUGH EXTENDING FROM 31N73W TO NW BAHAMAS WILL MOVE W AS ATLC RIDGE BUILDS A LITTLE STRONGER FROM BERMUDA TO NE FL THROUGH MID WEEK. STILL SOME EVIDENCE OF AN INVERTED TROUGH S OF 25N ALONG ABOUT 73W MOVING SLOWLY W. THIS TROUGH IS BARELY EVIDENT IN GUIDANCE AND SEEMS TO GRADUALLY WEAKEN AND LOSE N AMPLITUDE...WITH ONLY A SLIGHT TRACE OF A TROUGH MOVING THROUGH THE CAY SAL BANK LATE WED AND THROUGH THE FL STRAITS LATE THU INTO FRI...BUT ENOUGH OF A WIND SHIFT AND CONVECTIVE ENHANCEMENT TO CARRY ON GRAPHICS. ALTHOUGH LATEST ASCAT PASS FROM MON MORNING SUGGESTS E WINDS AT ONLY 15 KT E OF THROUGH... TWO SHIPS REPORTED E 20 KT AND SEAS 8-10 FT AT 00Z...SO PERHAPS THERE IS A DIURNAL GRADIENT OVER AREA N OF PUERTO RICO TRENCH...SO WILL FORECAST THESE CONDITIONS E OF TROUGH THROUGH PERIOD...ESPECIALLY AS THE GASTON REMNANT LOW MOVES W ACROSS THE N CARIBBEAN ALONG 17-18N. CARIBBEAN SEA AND TROPICAL N ATLC... SE FLOW IS AT 15-25 KT ACROSS THE GULF OF HONDURAS ATTM PER 0330Z ASCAT PASS...BUT EXPECTED TO DIMINISH TO 20 KT LATER TODAY AND 15 KT TONIGHT. CONVECTION NEAR REMNANTS OF GASTON CONTINUES TO FLARE BUT ONLY INTERMITTENTLY...WITH THE LLCC TRACKING W ALONG 17.5N. ALTHOUGH RECON FOUND 30 KT ON TUE...CURRENT OBS FROM LEEWARDS ISLANDS ARE MUCH LESS. NHC DROPPED CHANCE OF REDEVELOPMENT TO LOW CATEGORY..SO WILL DROP MENTION OF POSSIBLE TROPICAL CYCLONE FROM ALL GRAPHICS AND ALPHANUMERICS. WILL TONE DOWN THE FORECAST TO 20-25 KT INITIALLY...AND 15-20 KT FROM 24-36 HRS...AND 15-20 KT THEREAFTER...AND ONLY OVER N SEMICIRCLE. ALSO ADJUSTING DOWN ASSOCIATED SEAS...BUT NOT AS LOW AS NWW3 GUIDANCE...AS THE WEAKENING LOW MOVES W ALONG 17-18N ACROSS THE CARIBBEAN PASSING BY JAMAICA FRI AND SAT. CONVECTION IS NOW FLARING WELL E NEAR 17N31W WITH HINT OF CYCLONIC ROTATION.... WILL MOVE THIS SYSTEM W AS AN INVERTED TROUGH UNTIL WE CAN CLOSE OFF A SURFACE LOW. WARNINGS... SUBJECT TO CHANGE BASED ON LATEST NHC ADVISORY SW N ATLC... .NONE. CARIBBEAN... .NONE. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .TS WRNG FROM 24N TO 27N W OF 96W ENDING EARLY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON