A winter storm watch was posted by the National Weather Service this afternoon for 2 to 4 inches of snow by dawn Friday and another 2 to 4 inches of snow during the day.
Forecasters said they are not confident enough in the arrival of the storm to upgrade the winter storm watch to a winter storm warning.
But if the incoming system evolves as shown on some computer models, it could mean significant snow over the urban areas and surrounding locales.
A weather feature known as a deformation band was expected to set up over Eastern Washington and the Coeur d’Alene areas on the north side of a storm system tracking inland starting tonight.
Included in the watch are Davenport, Cheney, Rockford, Post Falls and Hayden and surroundings.
The type of storm in the forecast is known for bringing some of the heaviest snow to the region over the years and involves the suspension of warm moist air in the precipitation zone of the middle atmosphere.
Since these weather features are relatively narrow in nature, locales beneath the center of it could see dramatically greater snow depths than areas at the fringes, forecasters said.
Across the broader region, snow is likely east of a line running from Republic to Lewiston. A winter storm warning is in effect for far Northeast Washington and much of North Idaho. Colville could see 3 to 5 new inches of snow with 6 to 10 inches in the mountains.
Temperatures are supposed to stay at or below freezing with a high Friday of 32 around noon with colder air expected to arrive on the back end of the storm.
The incoming storm follows a break today in the winter-like conditions across the Inland Northwest.
Significant snow accumulations were reported in areas north of Spokane Wednesday and this morning, while urban areas were spared the heavy snow after conditions turned rainy overnight. Black ice, however, is triggering numerous accidents.
Colville appeared under a blanket of snow on traffic cameras. Also, a winter storm warning was in effect until 10 a.m. for portions of North Idaho, including Sandpoint, Bonners Ferry and Kellogg.
Forecasters said there is a chance of showers today with cooler air aloft bringing the possibility of snow showers by this afternoon.
There will be plenty of cold air to set the stage with a low tonight in the middle 20s.
Spokane’s forecast currently calls for 2 to 5 inches starting in the overnight hours tonight.
Coeur d’Alene could see an additional inch.
Gusty winds will accompany the storm and bring the wind chill feeling on the skin to near zero Friday night when the low hits about 15. Gusts from the middle 20s to lower 30s are expected Friday night.
The weekend also will be cold with lows near 15 on Saturday night and highs in the upper 20s to about 30 on Saturday and Sunday.
An easing of the cold is expected next week with highs in the lower 40s and lows near freezing. Showers are in the forecast next week.
The early look ahead to Thanksgiving weekend shows a trend toward autumn-like weather under a southwesterly flow that results in moist Pacific stoms hanging up over the Cascades and western portions of Oregon and Washington. Freezing levels may rise over the Cascades under that scenario.
The valleys should be mostly safe from snow as it looks now, but forecast models are not reliable beyond six or seven days.