Dry, mild stretch in northwestern US to come to abrupt end this week as storm train arrives

By Renee Duff, AccuWeather meteorologist
October 21, 2018, 11:52:30 PM EDT

After a prolonged dry and mild stretch, the northwestern United States will experience a flip to cool, rainy weather as Pacific storms return this week.

Residents and visitors can keep rain jackets and umbrellas tucked away and sunglasses nearby as a large area of high pressure will keep the region shielded from rain and clouds through Monday.

Highs will be in the 60s F around Seattle and 70s F in Portland, Oregon, making for comfortable conditions to leaf peep, pick pumpkins or complete yard work.

Static Monday NW

The calm, stagnant conditions will result in poor air quality across much of eastern Washington and Oregon into Monday, so children, the elderly and those with preexisting respiratory problems may have to limit time outdoors.

Increasing clouds on Tuesday will be the first sign of the changes to come for the remainder of the week.

Following a couple of mainly dry weeks in the Pacific Northwest, the area of high pressure will work its way far enough inland for Pacific storms to finally reach the region this week, according to AccuWeather Senior Meteorologist Jack Boston.

“The storm systems will bring back rain and mountain snow chances,” he added.

Download the AccuWeather app to know exactly when wet weather will return to your area.

Two to three storms are forecast to roll through the area with opportunities for wet weather throughout the week. The first storm will arrive late Tuesday, and a second will follow by Thursday. There is also the potential for a third storm to sweep in by the end of the week.

NW Oct 20

The storms during the latter half of the week are likely to bring the most widespread, soaking rain when compared to the storm late Tuesday.

The bulk of the rain will focus on western Washington and Oregon, but a few showers can make it inland to Idaho and western Montana. Northern California may barely be brushed by rain.

Motorists will need to use caution on the roadways, including Interstate 5, as the rain will mix with oil residue left behind during the dry spell to create slick conditions.

Temperatures will be knocked down a bit along with the stormy weather, but not enough for a big snow event in the Cascades.

Snow levels will remain confined to the highest peaks, well above I-90’s Snoqualmie Pass.

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While the return of damp weather may be to the dismay of outdoor enthusiasts, the region is in need of a thorough soaking.

All of Oregon and nearly all of Washington have been suffering from a worsening drought since the beginning of the summer.

The upcoming wet pattern will not be enough to fully wipe out these dry conditions, but it will be a first step in their improvement.

Air quality will also greatly improve across interior areas.

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