Need help protect from Weather effect

If blizzard tech support can't fix it or add "on/off" weather option. Is there a program or anything that can get rid of weather effect? Because you know it is weird when I play the game, my FPS runs smooth without weather, when it come to any zone where I am or enter, FPS became very slow and I tried most of video options, video card upgraded and etc.. it still won't fix. GM told me to post here so thought you guys know how to fix it or get rid of it like program for anti-weather or delete or turn off from WoW's weather folder dictory?