Weather Synopsis for Saturday night through Monday

3:52 PM: Adjusted Sunday's snow water equivalent numbers.

Moist WNW flow continues to transition the Pacific Northwest into an active weather pattern. Increasing light rain and snow continue to focus on the central and northern Washington Cascades Saturday night. Expect moderate accumulations in the westernmost part of the range as W winds deposit moisture from low cloud and moderate winds accelerate over the Cascade Crest and down the east slopes of the Cascades.

A cold trough slides down the British Columbia coastline, approaching the Pacific Northwest on Sunday. Moderate to strong W and WSW ridgeline winds accompany moderate to heavy rain and snow. The heavier precipitation might bring a subtle drop in snow levels with cooling during the day at 5000 ft and above, but not at pass levels. The surface cold front pushes through from NW to SE Sunday evening shifting the heaviest precipitation through the central and southern Cascades. Moderate to heavy snow showers transition to light to moderate snow showers as temperatures plummet behind the front. Snow levels will be below 1500 ft in all areas by Monday morning as a cold trough continues to spin light to moderate snow showers and convergence bands into the area. Expect 1-2" of snow water equivalent for the west slopes of the Cascades through 4 PM on Sunday, with 5-15" of snow above the 3500-4000 ft rain/snow line. An additional 1-1.5" is likely for the west slopes of the central and southern Washington Cascades. Sunday night through Monday with another 10-15" of snow, including at lower elevations.