Spokane expected to avoid the next blast of rain; mountain passes could see feet of snow by Friday

Spokane will likely avoid the heavy rains drenching much of Western Washington and the Idaho Panhandle, according to the National Weather Service.

“We’ll be dry through Sunday night,” according to Daniel Butler, NWS meteorologist. Between Monday and Tuesday, Butler forecast ¼ to ½ inches of rain: “a minimal concern,” he said.

“The greatest concern,” however, lies in the Idaho Panhandle and “near the Crest of the Cascades,” Butler said.

“Monday morning, another atmospheric river arrives in the Pacific Northwest, and it’ll be raining even in the higher elevations.”

He cited snow elevations at 6,000 to 8,000 feet through Monday, though those figures are expected to change Monday evening into Tuesday.

“Those snow levels start to fall around 4,000 to 5,000 feet, so we’re a little bit concerned about flooding issues,” he said. Again, those concerns lie outside of Spokane County.

Beginning on Tuesday, Snoqualmie Pass is projected to receive 2 to 3 feet of snow through Friday, Butler said. Stevens Pass and Lookout Pass, during the same period, will get 4 to 5 feet and 1 to 2 feet, respectively.

“What happened this past week, since the snow levels were above 8,000 feet, (is that) even the mountain passes saw a bunch of rain,” he explained.

So far, Stehekin in Chelan County “saw 4.25 inches of rain” between Tuesday and Thursday, while Bonner County received 3.9 inches. Leavenworth had 2.49 inches, while the Crest of the Cascades and other areas in the Western slopes were reported to have faced 10 to 15 inches, Butler said.

The excessive rain is caused by an atmospheric river.

“It’s basically a column of moisture that comes from deep within the subtropics, so like 20 to 30 degrees latitude. A lot of times, the origination source for all this moisture is around Hawaii,” he said.

This particular system comes from further West, though, near the International Date Line, he noted. Mixed with a “high-pressure system off the coast of Oregon and California” and a “low-pressure system in the Gulf of Alaska.”

“Those two together combined directed all that moisture from deep within the subtropical region up right into our area for quite a few days,” Butler said.