Avalanche Forecast

Cool and showery weather will continue Sunday. Some shallow new snow is likely to accumulate above treeline Sunday and while expected winds should be light, any locally stronger winds may drift new snow and build some shallow wind slabs, mainly near ridges on lee slopes. A high degree of uncertainty exists in the expected new snow amounts, so watch for heavier showers that may quickly build new snow layers and be prepared to change travel plans and remain on lower angled slopes, avoiding exposure to steeper terrain above.

At lower elevations, daytime warming and possible rain showers will maintain shallow wet snow conditions Sunday where you could still trigger Loose Wet avalanches on steep slopes. While they are generally smaller and easier to predict, Loose Wet avalanches can be dangerous if they push you off cliffs, through rocks, or into gullies.

Cornices and Glide avalanches have been active in the past week. The cooling trend may take an additional few days to have an effect on these avalanche problems. Avoid stopping under known rock slabs and slopes with visible glide cracks.  Continue to put a wide buffer of terrain between you and any cornices. They will often break surprisingly far back from the edge. Make sure you are well off of and out from under cornices as you travel through the mountains.

The cooling temperatures, clouds, and light precipitation this weekend is causing the previously wet and weak surface snow to gain strength as it freezes. A long stretch of warm weather and strong sun ushered in spring-like conditions last week. An extensive cycle of Loose Wet avalanches, cornice falls, and Wet Slabs occurred in the past week throughout the Cascades.

Generally, Wet Slabs or slab avalanches entraining wet snow in the past week have occurred in the upper snowpack with a few deeper releases reported. In the Mt Baker area and North Cascades National Park west of the Cascade Crest observers have reported a significant cycle of slabs 3-6 feet (1-2 meters) deep. One observer reported probing a widespread weak layer 3 meters below the surface on the Silver Glacier.

Alpental pro patrol reported extensive cornice falls this past week, including on Friday. Some of these cornices were very large, but were not triggering significant avalanches on slopes below. As of Saturday morning the cooling temperatures were helping firm the surface snow as the well drained and consolidated snow began to refreeze at mid and upper elevations. Only very shallow wet surface snow was reported at lower elevations.  

On Friday, Forecaster Dallas Glass toured near Paradise on Mt Rainier. Dallas reported a recent cornice fall, a few Wet Slab avalanches up to size D2, and numerous Loose Wet avalanches. While the upper snowpack was moist to wet, it remained supportive.

On Thursday, Dallas Glass reported a natural cornice fall as well as easily triggering Loose Wet avalanches near the Alpental Valley. Dallas reported that a thin surface crust quickly softened in the morning.