According to the National Weather Service, a Winter Storm will impact northern California this Friday (Halloween) and Saturday, November 1.
The rain and snow will first begin across most of northern California on Friday.
Rain showers or thunderstorms are expected during Halloween trick- or-treating. The possible thunderstorms will most likely impact the Mother Lode and the central valley on late Friday afternoon and evening.
Snowfall will continue in the Sierra Nevada mountains on Saturday. Snow levels will lower to 4000 feet by Saturday morning. Several inches of snow is likely.
Significant travel delays and hazardous travel is expected over the mountain pass highways that remain open.