A winter weather advisory has been posted for Spokane, Coeur d’Alene and the northern Palouse starting at 10 p.m. and continuing until 4 p.m. Wednesday.
One to 3 inches of snow is likely over most of that portion of the region through morning with an additional inch possible every 12 hours after that through Thursday afternoon, National Weather Service said.
To the north, a more severe winter storm warning was issued for areas of North Idaho north of Garwood, as well as a wide portion of the Panhandle mountains and for Northeast Washington from tonight until 10 a.m. Thursday.
Accumulations of 5 to 9 inches are likely in those areas, with more in the mountains.
In addition, a second wave of snowfall is expected to form in a narrow band across the region on Wednesday, but it was unclear where additional snow might fall as of this afternoon, forecasters said.
A potent Pacific storm is approaching the coast of Washington and will migrate inland tonight.
Forecasters said it should reach Spokane by no later than 11 p.m.
Temperatures are going to drop to the middle 20s tonight, ensuring sufficient cold air for snow, and then warm to the middle 30s on Wednesday.
Spokane has a 60 percent chance of snow showers on Thursday with an accumulation of about an inch.
Temperatures could moderate by the weekend and change precipitation to rain showers in the Spokane area.