Winter storm moving south; light snow expected in Inland NW

The National Weather Service said Thursday morning that an evolving forecast has resulted in a downgrading of the snow threat for much of the Inland Northwest.

A large winter storm streaming ashore from the Pacific is going to graze the Inland Northwest with 1 or 2 inches of snow through Friday afternoon.

Light snowfall in the Spokane region should start around 10 p.m. Thursday with about an inch accumulating by 10 a.m. on Friday.

However, the storm should linger for several days, ensuring that nearly all areas will receive at least light accumulations through the weekend.

Friday night and Saturday combined could bring another 2 to 4 inches of snow to the Spokane region.

Winter weather watches and warnings have been dropped for much of the region, while a mix of warnings remained in effect across other parts of the Pacific Northwest, especially in mountain areas.

On Thursday afternoon, the weather service extended a winter weather advisory to the Palouse region of Idaho and Washington for 1 to 3 inches of snow through 10 a.m. on Friday.

The Cascades and adjacent valleys, Central Panhandle Mountains and the lower Columbia Basin are under the gun for a stronger winter storm.

The Central Panhandle mountains could see 8 to 12 inches of snow while adjacent valleys should see 5 to 8 inches through early Saturday.

The Cascades could see a foot or more.

Mountain pass travel may be slowed as a result.

Thursday morning’s forecast discussion from the weather service in Spokane said, “The battle between the drier and cold polar continental air to the north and milder and moist Pacific maritime air to the south will continue over the region into Monday.”

“(Computer) models show another quick hitting trough of lower pressure for Sunday night. Confidence for where snow will develop is low as it will depend on where the boundary between these two air mass comes together,” the discussion said.

Temperatures are expected to moderate by this weekend with highs in the low 30s and lows in the middle 20s, which are normal for this time of year.

Thursday’s high should be in the middle 20s.

Forecasters said that more arctic cold is possible by Monday night or Tuesday with highs in the teens and lows in the single digits to about 11 degrees.

To the west of the Cascades, the weather service has issued a winter storm warning for much of northwest Oregon and southwest Washington Thursday, prompting Portland to close all city offices and dozens of schools to delay or cancel classes.

The service says an unusually strong winter storm will bring with mixed precipitation in the greater Portland and Vancouver, Washington, areas.

Officials say snow will start falling Thursday and then change to freezing rain in the coastal mountains and inland areas. Freezing rain is predicted to continue inland until midnight and especially near the Columbia River Gorge with up to a quarter inch of ice possible.

The weather service says generally from 2 to 4 inches of snow could accumulate.

In the greater Seattle area, a winter weather advisory for up to 3 inches of snow in the lowlands has been issued from Thursday afternoon through Friday morning.

The Associated Press contributed to this report.

Cold, snowy conditions are expected to persist east of the Cascades through next week with another snowstorm possible around Wednesday evening or Thursday, forecasters said.