Cooler Temperatures and Showers Ahead for Seattle as Fall Weather Arrives

A brief reprieve is expected on Monday as a weak ridge of high pressure attempts to settle over Western Washington.Photo byZhifei ZhouonUnsplash

The National Weather Service in Seattle has issued a weather update indicating a shift to cooler and wetter conditions as a series of weather systems moves through the region over the weekend.

The weather pattern is expected to change significantly today as a weak upper-level ridge that has been providing mild conditions shifts eastward by late morning. In its place, an upper-level trough will arrive tonight, bringing with it increased shower activity. The best chances for showers will be along the north coast of Washington. With the cloud cover, temperatures are forecasted to be 5 to 10 degrees below normal, reaching only the lower to mid 60s.

As the upper-level trough moves overhead tonight, showers are expected to intensify, continuing into the early hours of Saturday. Overnight lows will dip to the mid 50s.

The trough will remain in place over the weekend, with a closed upper-level low developing within the trough. This will lead to enhanced shower activity on Saturday, particularly in the afternoon and evening. Despite a slight decrease in precipitation on Sunday as the trough begins to move south, the region will remain under the influence of unstable air, keeping the chance of showers in the forecast throughout the day. High temperatures over the weekend will stay well below normal, again in the lower to mid 60s, with morning lows ranging from the mid 40s to lower 50s.

A brief reprieve is expected on Monday as a weak ridge of high pressure attempts to settle over Western Washington, potentially providing a drier day. However, the respite will be short-lived as a front approaches from British Columbia, expected to reach the area by Tuesday night.

Following this front, an upper-level ridge is anticipated to build over the region from Wednesday night into Thursday, potentially bringing more stable and drier conditions.