Black Ice and snow is unusual for Western California so is very dangerous to locals

Snow is very unusual for Western California in the Counties including San Francisco county and counties  to the north and as far south as Big Sur in Monterey County. So, if you are local or visiting and you are above about 1000 feet or 2000 feet especially at night in elevation look very carefully for black ice because locals aren't used to this condition and it might be fatal for unsuspecting drivers. Black ice and snow in general often Californians who don't live in mountains have never experienced driving in these conditions before and this could be fatal or injurious to your health.