The National Weather Service late this morning issued a winter weather advisory for the Spokane and Coeur d’Alene areas for the possibility of sleet and freezing rain after 10 p.m.
Forecasters said that if conditions are right, as much as a tenth of an inch of ice could accumulate. However, warming temperatures may save the region from the threat of freezing rain.
A chance of snow, freezing rain and rain arrives tonight and threatens to make driving a challenge until temperatures warm into the middle and upper 30s by mid-day Wednesday.
Forecasters said cold air in place over the Inland Northwest is going to be overrun by a moist and mild Pacific storm system.
Initially, the cold air layer will be thick enough to keep the precipitation as snow, but as the storm deepens over the region it will displace the cold with milder air.
During the transition, precipitation is expected to become a wintry mix with freezing rain possible along a line from Moses Lake to Davenport, Spokane and Coeur d’Alene and then northward to Sandpoint.
No more than a half inch of snow is expected after 4 p.m., and then the wintry mix should start falling before 10 p.m. bringing no more than another half inch.
Light precipitation is expected through the evening with heavier amounts overnight into Wednesday morning.
Forecasters said they do not expect any large ice accumulation from freezing rain.
The winter weather advisory is in effect from 10 p.m. to 1 p.m. Wednesday and includes Cheney, Hayden, Post Falls and Rockford.
A separate winter weather advisory was posted for areas north and west of Spokane and Coeur d’Alene for up to 3 inches of snow tonight and Wednesday.
Highs today are expected to reach 31 in downtown Spokane and 36 in Coeur d’Alene with lows tonight near freezing.
Partly cloudy skies were apparent at dawn as spots of sunshine appeared through a high and middle elevation clouds.
Snow levels rise to 4,000 feet tonight as the milder air makes its way inland. On Wednesday they hover between 2,900 and 3,600 feet, well below ski hill elevations.
The chance of showers – most likely rain – will continue through the week with highs in the upper 30s and lows at or just above freezing.
A mild and wet storm system is possible on Sunday when highs go to 40 in downtown Spokane.
At 7 a.m., it was 24 at Spokane International Airport, 28 at Felts Field, 27 in Deer Park and Coeur d’Alene and 33 in Pullman.
East winds in Pullman are helping scour out the cold air sooner than in Spokane.
A winter storm watch was in effect for the east side of the Cascades, the Okanogan region and mountain areas along the Canadian border, including Omak, Republic, Colville, Bonners Ferry and Sandpoint.
Cold air trapped against the mountains may cause more precipitation to fall as snow in those areas tonight and Wednesday, forecasters said.
Snoqualmie Pass on Interstate 90 could see snow today mixed with rain. It was bare and dry with occasional snow at 7 a.m.