Small avalanches will be possible above treeline. You may still be able to trigger small wet slides on very steep, sunny slopes. Expect the avalanche danger to increase on Sunday.
Warming temperatures and sunshine will keep loose wet avalanches running on very steep, sun-exposed slopes. Look for signs of loose wet activity such as rollerballs, and other small fan-shaped avalanches as temperatures warm. The potential size of loose wet slides will increase where you find more recent snow, such as the mountains northwest of Cle Elum.
Avalanches will be possible near the Cascade crest. Look for signs of instability such as shooting cracks and recent avalanches. Use caution on leeward slopes that are steeper than 35 degrees. Steer around drifts, wind features, and convex rollovers.
Give cornices plenty of room when traveling on ridges and stay out from under them. Travelers are surprised every season when cornices break further back than they expect.
(3/22/2021) Small wind slab release on a test slope. Notice the rippled texture to the snow surface.
As is typical for the East Central zone, snowfall totals vary widely from Wednesday's storm. Near 8" accumulated in the southwest portion of the zone and snowfall amounts taper off to 1" for areas to the north and east. At Mission Ridge, westerly winds were strong on Wednesday with gusts into the 60's. The new snow fell on a mix of sun crusts on the east to south to west aspects and cold dry snow surfaces on northerly aspects. Small near-surface facets were observed above treeline in the neighboring Stevens Pass zone last week, prior to the last two storms. On Monday, an observer in the Van Epps Pass area found around 8" of new snow.
A crust and adjacent weak layer formed in mid-January can still be found about 2-6 feet below the surface throughout most of the zone. Several different avalanche cycles released down to this interface, with the last cycle producing avalanches up to size D4. Avalanches on the mid-Jan crust/facet layer are now unlikely with the last one reported on March 1st. We're watching the upcoming weather pattern for major warm-ups or storm events to see when and if these deeper layers will be tested again. The most suspect areas for deep persistent slabs are shallow, rocky, and unsupported slopes, especially where overhead cornice fall could trigger avalanches.w
