The National Weather Service (NWS) has issued a Sierra Winter Storm Watch beginning this morning through Sunday afternoon in anticipation of the first winter storm of the season this weekend. Sierra travel will be impacted with intermittent chain control periods anticipated Friday through Sunday on Interstate 80, U.S. Highway 50, and secondary area highways. Motorists are advised to be prepared for winter travel and carry chains as permitted chain installers do not sell traction devices. Up to a foot of snow is anticipated over the weekend on I-80 at Donner Summit and U.S. 50 at Echo Summit. Snow levels may also fall to the 2,500 or 3,000-foot elevation by Saturday morning. In addition, rain in valley areas will cause slick roads throughout the weekend. Motorists are reminded to slow down based on weather conditions and to use headlights, even during daytime hours, when rain is falling.