Fog of war and or fog environmental card

[ch82]

I've been wondering if there was some way to add fog of war to this game. Short of the zombie player marking zombie movement on a piece of paper I don't think there is an elegant way to do it. Having an environment card that obscures vision would be good too. Just thinking of a way to help up the tension when wandering around outside not knowing where the zombies may be lurking only to see 3 walkers suddenly emerge out of the mist.

ALSO:

I'm thinking that if a building has lights out then zombies should have some sort of advantage vs range weapons. If you are shooting into a blackened building or even standing at the opposite end I doubt you are going to be hitting zombies with head shots.