Wind storm likely for the Columbia Basin and Spokane on Friday

Mostly dry weather (with a few isolated showers) comes to an end on Friday as an atmospheric river takes aim at the Pacific Northwest. This is likely to bring the first wind storm of the season to much of the region, including the Columbia Basin, Palouse, and Spokane area culminating during the afternoon hours.

Current modeling suggests that wind gusts may peak around 40-50 mph throughout much of Eastern Washington, though the Yakima Valley (including Yakima itself) is likely to be sheltered by terrain. The map at the top of the article shows one model solution, the ECMWF, at 17:00 PDT Friday. Exposed locations, such as open fields, will see stronger winds than places in town which are surrounded by trees and buildings. The top of Rattlesnake Mountain may see gusts to 70 mph.

Still, that does not mean that there won’t be impacts in town. Now is a good time to prepare by securing outdoor furniture and trampolines. Power outages will be possible as well, so make sure to have devices charged. Travel will be difficult on many highways with significant blowing dust possible along I-90, US 395, and other highways near Moses Lake and Ritzville.

The culprit for the strong winds will be a tight pressure gradient between a strong high pressure system located midway between San Francisco and Honolulu and a strong low pressure system that is forecast to cross British Columbia during the day Friday. Air is constantly trying to move from areas of high pressure to areas of low pressure, with stronger wind speeds in areas where the difference in air pressure is stronger, such as what is forecast over the Pacific Northwest on Friday.

Gusty winds are likely to continue into the day Saturday but will not be as strong since the low pressure system will be further away – moving off toward Saskatchewan and Manitoba. Gusts to 20-30 mph in the Tri-Cities and 30-40 mph around Spokane and on the Palouse appear to be favored by the modeling. Things calm Saturday night as cooler air settles to the ground, separating the surface from stronger winds higher up.

Wind is not the only condition expected out of this event. The low will sweep a warm front across the Inland Northwest during the day followed by a cold front that evening. Rain showers are possible during the day with rain likely overnight as the cold front moves through. Shower activity remains possible through the weekend before the next system approaches on Sunday.

An active weather pattern continues into next week with some systems bringing a chance of low elevation snow. Snowflakes have manifested themselves on generic weather apps in most of Washington and parts of Oregon. Weather apps are generally fine for figuring out what to wear when you’re getting dressed in the morning, but things like snow totals, or whether it will snow at all with temperatures near freezing, are a bit too nuanced for a computer (even a good one) to pin down accurately.

It is true that some snow flakes are possible in the Columbia Basin next week with possibly a few inches around Spokane. Anything more specific than that is just hearsay at this point. Some weather models have spat out crippling amounts of snow, but when all of the models are taken as a whole it’s clear that most of the ensembles favor lower snowfall totals. Details will become better resolved toward this weekend and the beginning of next week.