Published October 29, 2017
Following a stretch of dry, calm and mild weather, residents and tourists in the northwestern United States will be in for a rude and wintry awakening at the end of the week.
“A few more days of nice weather can be expected early this week; however, by Wednesday the threat for rain returns with a strong disturbance expected to dive out of western Canada,” AccuWeather meteorologist Max Vido said.
The first signs of the incoming weather will show at midweek as cloud cover increases and temperatures and high-elevation snow start to fall across Washington, Idaho and Montana.
By Thursday, these impacts will expand over Oregon and much of California.
Strong winds are expected to accompany an onslaught of heavy snow over the Cascades, Bitterroots and higher elevations of western Montana.
At the same time, rounds of heavy rain will start moving onshore, inundating coastal cities.
“This system will hug the Pacific coastline both Thursday and Friday, bringing frequent rain and mountain snow to Washington and Oregon,” Vido said.
“Temperatures will also fall to below-normal levels as the dip in the jet stream drags cooler air southward.”
The jetstream is a high-speed river of air at the level where jets fly. North of the jetstream, temperatures are typically lower.
Thermometers will easily reach into the 60s F in Seattle and Portland early this week, but will struggle to exceed 50 F on Friday.
In addition to the wet and cool conditions, gusty winds will make the weather feel especially raw. AccuWeather RealFeel Temperatures® will be much lower than the forecast high temperatures in the 40s.
Strong winds could also cause travel delays and result in some damage. Localized power outages are not out of the question.
“Rain will be possible in Northern California by Friday, with the potential for unsettled weather reaching Southern California over the weekend,” Vido said.