The Boise area and much of the Treasure Valley could see 1 to 3 inches of snow by the time a winter storm moves through the region Friday evening and Saturday morning.
The National Weather Service has issued a winter weather advisory for the Upper Treasure Valley from 5 p.m. Friday through 5 a.m. Saturday. The heaviest snow will fall in the Foothills and mountains, but there will be enough accumulation at lower elevations to impact travel conditions. Winds from the south will cause blowing and drifting snow.
The Ada County Highway District spent Friday applying deicing compounds to major roads, intersections, bridges and other priority areas to help motorists maintain traction.
The snow will begin to fall around 5 p.m. Friday, with the bulk of the snowfall coming from 6 p.m. to midnight, according to the National Weather Service. The snow will taper off Saturday morning.
The temperature in Boise was 29 degrees at 3 p.m. Friday. The overnight low is expected to drop one degree. Saturday's high is expected to reach 38 degrees.
Pretreating roads ahead of the storm prevents ice from bonding to the pavement, said Jim Buffington, the highway district's maintenance manager. If the snowfall is particularly heavy, the district will use sand and salt on roads and use snow plows, if necessary.
The district maintains more than 2,260 miles of local streets in Ada County. The Idaho Transportation Department handles state highways, Interstate 84 and the Boise Connector, I-184.