REPUBLIC A winter storm advisory is in effect for the Methow Valley, Okanogan Highlands and Ferry County until 7 a.m. Thursday.
The advisory means travelers should be prepared for snow-covered roads and limited visibility.
According to the National Weather Service, heavy snow is expected is Mazama, Winthrop, Twisp, Republic, Inchelium, Wauconda and Chesaw.
In the Methow Valley, overnight snow accumulations are expected to average 6-11 inches.
“The heaviest accumulations will fall above 3,000 feet,” a weather report said.
The Weather Service said North Cascades passes – including Stevens, Loup Loup and Blewett – will exhibit “treacherous” driving conditions.
In Ferry County, overnight accumulations are expect to average 2-5 inches, and as much as 3-7 inches in mountain areas.
“Travel will become treacherous this evening,” the Weather Service reported. “Roads will likely be snow-covered through Thursday morning.