I came here for the express purpose of talking about snow. The snow today and this evening is not supposed to be bad at all, so I don't anticipate any problems. However, if we do have a blizzard moving forward into the winter I'll cancel the game, because Josh does not drive in the snow.
In general if I'm going to call a game you'll be able to see here in the forums on that Friday. I'll have cancellations up by lunch time.
That's how I'll handle it if I'm sick or get shot or anything like that as well.
On game days when we don't have enough people to play we'll probably arrange other entertainments. Boardgames and such. In the past we gave item rewards and the like for participating in these non-D&D events. On days when it snows and I decide not to go because I'm a wimp, if everyone ELSE goes and you guys are willing to vouch that fun was had by all, I can give item rewards for that too.