I had to grab this headline from todays San Francisco Chronicle. They claim we may have some snow in SF this weekend. Last time was 1976. This should make for a pretty crazy driving experience for those they have not lived in the snow belt. Maybe you can pick up some 'snow tires' at Sears before the 1" of snow hits the ground. Might consider picking up a snow blower too!
We had snow in the upper elevations this past weekend which is an annual occurance but I've never seen it land in SF.