Having sub par graphics card (ATI 4800 1GB VRAM) I (and a few guildies) experience a very sharp fps drop when weather in WvW kicks in, to the point of halving fps while I’m just standing idle in a non-sieged castle while the enemy holds weather.
Granted the video card isn’t adequate for sieges (even though it performs fine outside of clusterkittens). I think the shader can be optimized better as similar and more sophisticated weather effects hardly affect FPS in other games.
Perhaps I’m wrong or this is a minority issue, I’m putting this in here just in case it’ll get noticed by someone who can take a peek what can be done about it.
HTH.