3 Storms To Soak Seattle, Starting Friday: Puget Sound Rain Forecast

SEATTLE — It's finally happening. After logging little more than a half-inch of rain since mid-June, making for the driest 120-day stretch in Seattle history, the inaugural storms of autumn are on Puget Sound's doorstep.

The first of three incoming fronts is due late Friday morning and will make quick work of the lingering smoke that lent the Emerald City some of the worst air quality in the world Wednesday and Thursday, and the rain should go a long way in tamping down the flames at the source.

The National Weather Service expects showers will begin to build along the coast early Friday, spreading inland through the afternoon and evening. Cities across central Puget Sound can expect up to an inch of rain by Saturday morning, and two more systems should help run up the totals through Wednesday.

Heavier rain is forecast to transition to more showery conditions Saturday, but a potential convergence zone developing could mean a downpour for areas near the King and Snohomish county line.

Wind gusts will be possible across the region but should max out under 20 mph for most of the lowlands Friday and Saturday.

Forecasters expect a few breaks between systems Sunday and Tuesday, and temperatures in the lowlands should stick to the mid-50s during the day and mid-40s at night through at least mid-week.

In the Cascades, which may see the heaviest rains Friday, snow levels are due to dip under 4,000 feet through the weekend, likely bringing a few inches of fresh snow to the mountains. Officials at Mount Rainier National Park urged visitors headed to higher terrain over the weekend to plan accordingly for winter conditions and elevated risks.

With several months since the last big rain, forecasters are reminding drivers to be cautious on their commutes as built-up oils return slippery roads to Western Washington, noting it can take vehicles twice as long to stop on wet surfaces.

The National Weather Service will also be keeping an eye on burn scars around several Cascade wildfires, including the Bolt Creek Fire, where heavy rain can quickly spur unpredictable debris flows — fast-moving and potentially deadly landslides.

A second, potentially wetter system is forecast to arrive late Sunday afternoon, followed by another vigorous pattern expected Tuesday night and lasting into Wednesday. The National Weather Service will share more about next week's expectations as the forecast firms up. The Climate Prediction Center's long-term outlooks favor cooler, wetter conditions winning out through the end of the month.