Washington Mountain Snow and Rain Midweek Before Cooler Pattern

Unsettled weather continues across Washington with periodic showers into Tuesday. A stronger frontal system arrives Tuesday night through Wednesday bringing steadier rain to the lowlands and the first widespread mountain snow of the season. Conditions stay showery and cooler into late week before a gradual drying trend develops over the weekend into early next week.

Scattered showers persist at times into Tuesday with high temperatures in the mid to upper 50s. Steadier rainfall returns to the lowlands Tuesday night into Wednesday, especially around Puget Sound. Southwest winds will increase late Tuesday, reaching 20 to 30 mph from Seattle to Tacoma and westward toward Shelton. Highs cool slightly into the low to mid 50s on Wednesday.

Snow levels will fall from around 4000 to 4500 feet to 3000 to 3500 feet by Wednesday morning, bringing accumulating snow to the higher Cascade and Olympic passes. Expect 6 to 12 inches at White Pass and Paradise with local amounts up to 15 inches near Paradise, 4 to 8 inches at Stevens and Rainy Passes, and up to 3 inches at Snoqualmie Pass. Winter Weather Advisories are in effect for many Cascade zones from Tuesday afternoon through Wednesday afternoon. Light additional snow is possible at times Thursday and Friday as snow levels fluctuate between 2500 and 4000 feet.

Light rain moves through today into Tuesday morning with only modest amounts expected outside the far southeast. A colder system arrives Tuesday night through Thursday, dropping snow levels to 2500 to 3000 feet over the Cascades and north-central mountains. Winter travel conditions are likely at Stevens and Washington Passes, where the best chances exist for 6 inches or more of snow. Highs will cool into the 40s and low 50s with overnight lows in the 30s after the system passes.

An upper low lingers near the coast through Friday, keeping showers going at times with light mountain snow possible. Precipitation chances decrease over the weekend as the system weakens and a ridge begins to build. Temperatures trend cooler, and frost or freeze conditions will need to be monitored Saturday into early next week, especially in valleys and the Columbia Basin. A slow warming trend is expected by Monday.