Seattle (SEW) — the National Weather Service forecast in plain English · Plaincast

Synopsis

Troughing developing over the area will continue into this weekend, bringing unsettled conditions and cooler temperatures to the region. Ridging looks to rebuild through the first half of next week for a slow warming trend.

Short Term

An upper level trough over the region will continue to bring onshore flow, cooler temperatures, and unsettled weather to western Washington over the next couple of days. It'll deepen today as its associated upper-low forms off the BC coast and positions offshore by this evening. As a result, light shower activity is possible over the Olympic Peninsula tonight but conditions are to remain mostly dry across the area. Highs today will top out in the 60s to near 70 F with overnight lows in the 50s.

The upper-low will traverse across the region on Saturday, bringing widespread rain, showers and a 15-20% chance for thunderstorms. The highest probability for lightning is over the Olympics and southwest interior according to the the blend-of-models forecast. It'll hang around through Sunday with continued precipitation chances but the thunderstorm threat will diminish with probabilities less than 10%. High temperatures ranging between the 60s to near 70 F and lows mainly in the 50s for both Saturday and Sunday.

Long Term

Conditions are favored to trend drier Sunday night as the low center crosses east of the Cascades. Can't rule out lingering showers over the mountains. An upper level ridge will begin to build offshore on Monday, introducing a slow warming trend through midweek. Some ensembles suggest weak troughing Tuesday-Thursday that could bring some chance of rain to the region, but for now, looks like dry and warm conditions will manifest.