Travelers should be prepared for snow on the east slopes of the Cascades and in the Blue Mountains, according to the National Weather Service.
In the Tri-Cities more rain is expected, with a 50 percent chance of rain Wednesday and a 60 percent chance of rain Thursday night. Temperatures should continue to warm.
The high Wednesday in the Tri-Cities could hit the low 40s and by Martin Luther King Day the high could be up to 44. Lows should be about freezing or a little above through the three-day weekend.
In the mountains on either side of the Mid-Columbia, winter weather advisories have been issued through Thursday.
Five to 10 inches of snow on the east slopes of the Cascades and 6 to 12 inches in the northern Blue Mountains of Oregon and Washington could make for slow and treacherous travel, the weather service said.