We're planning a trip to San Francisco in late December. We'd like to visit Yosemite and stay in Oakhurst. Can anyone tell me if it can snow on the roads along the way. I'm trying to figure out if we'll need chains. If we don't, then we can drive at least to Oakhurst and do a Yosemite tour from one of the hotels. If we do, then we'll have to scrap the whole idea.