Mountain Weather

The frontal boundary that brought heavy precipitation to southern Washington on Tuesday has shifted into northern Oregon this Wednesday afternoon. Colder air has spread southward behind the front, bringing snow levels close to sea level across much of western Washington. Steady snowfall has ended over the northern Cascades, while lingering snow showers continue from Snoqualmie Pass southward through Mt Rainier. For this test scenario, snowfall totals since Tuesday night range from 3–6" in the central Cascades to 6–12" around Mt Rainier, with locally higher amounts near Mt St Helens and Mt Hood.

A weak trough moving southeast from Vancouver Island will maintain scattered snow showers through Wednesday evening. Convergence bands could bring brief periods of moderate to heavy snowfall to the central Washington Cascades, particularly between Stevens and Snoqualmie Passes. Additional accumulations of 2–5" are possible in these bands, while most other locations receive a trace to 2". Snow levels remain near the surface across northern and central Washington, lowering to 1500–2500 ft around Mt Hood. Moderate west to northwest winds along exposed ridgelines will gradually ease through the evening.

Snow showers diminish Wednesday night as the trough exits and a weak ridge builds offshore. Partial clearing and light winds will allow temperatures to fall sharply overnight. Thursday begins cold and mostly dry, with a few lingering flurries along the Cascade crest. Clouds increase from the northwest late in the day ahead of the next weak disturbance, with light snow potentially returning to the northern Cascades Thursday night as a warm front lifts northward across northern Oregon. It is too early to tell whether precipitation will remain focused across the southern Cascades or shift north into the central and northern Washington Cascades.

The frontal boundary that brought heavy precipitation to southern Washington on Tuesday has shifted into northern Oregon this Wednesday afternoon. Colder air has spread southward behind the front, bringing snow levels close to sea level across much of western Washington. Steady snowfall has ended over the northern Cascades, while lingering snow showers continue from Snoqualmie Pass southward through Mt Rainier. For this test scenario, snowfall totals since Tuesday night range from 3–6" in the central Cascades to 6–12" around Mt Rainier, with locally higher amounts near Mt St Helens and Mt Hood.

A weak trough moving southeast from Vancouver Island will maintain scattered snow showers through Wednesday evening. Convergence bands could bring brief periods of moderate to heavy snowfall to the central Washington Cascades, particularly between Stevens and Snoqualmie Passes. Additional accumulations of 2–5" are possible in these bands, while most other locations receive a trace to 2". Snow levels remain near the surface across northern and central Washington, lowering to 1500–2500 ft around Mt Hood. Moderate west to northwest winds along exposed ridgelines will gradually ease through the evening.

Snow showers diminish Wednesday night as the trough exits and a weak ridge builds offshore. Partial clearing and light winds will allow temperatures to fall sharply overnight. Thursday begins cold and mostly dry, with a few lingering flurries along the Cascade crest. Clouds increase from the northwest late in the day ahead of the next weak disturbance, with light snow potentially returning to the northern Cascades Thursday night as a warm front lifts northward across northern Oregon. It is too early to tell whether precipitation will remain focused across the southern Cascades or shift north into the central and northern Washington Cascades.