Snow is possible on the east slopes of the Cascades Mountains and in the Blue Mountains on Christmas Eve, said the National Weather Service.
A storm system is expected to move across the region Wednesday, bringing rain to the Tri-City area. Colder air is expected to filter into the region late in the afternoon.
Snow levels are expected to lower to 4,000 feet by Wednesday evening with light snow possible. The snow may accumulate along Interstate 84 in the Blue Mountains as well as Interstate 90 along the east slopes of the Cascades.
Motorists traveling during the holiday may experience slippery conditions along these roadways, forecasters said.
The rain will give way to mostly sunny skies on Christmas day with a high near 41.