East Slopes North

A return to colder more winter-like weather will help the snow surface freeze and limit any avalanche concerns. You may encounter variable surface conditions with breakable crust, icy slopes, and soft dry snow.

Thursday will be a bit of a transition day for the East North zone as we move from spring back to winter. Mostly clear skies for part of Wednesday night should allow the snow surface to freeze in most locations. As a storm starts to impact the region Thursday, cooler temperatures and cloudy skies should keep the snowpack “locked-up.” While we are expecting some snow later in the day, it shouldn’t be enough to impact the avalanche danger prior to sunset. 

This change in the weather may lead to variable snow surface conditions. Firm icy surfaces, breakable crusts, and frozen debris will be more common at lower elevations and on E-S-W aspects higher in the terrain. More shaded slopes could still hold cold dry snow in sheltered areas. 

Even though we aren’t forecasting any specific avalanche problems, keep your eyes peeled for conditions that aren’t what you expect. This could look like a very isolated wind-drifted pocket or areas of wet snow on the surface. 

Similarly, cornices weakened by the recent warm sunny weather continue to be a concern. On Wednesday, avalanche professionals in the Cutthroat area found a sizable “cornice-crevasse” hidden under a thin layer of snow. As we head deeper into spring, give this hazard plenty of space both along ridgelines and by not stopping/regrouping below them. 

While Thursday’s weather shouldn’t result in surprising deep avalanches, there are a few layers we continue to track. The Valentine's crust is 3-5 feet below the surface in the western half of the zone, including near Washington Pass, the upper Silverstar drainage, and Hart's Pass. You can expect to find shallower at lower elevations and further east. There have been numerous observations and snowpack tests indicating weak snow and poor structure exist below this crust. It's suspected to have been a weak layer for some of the very large avalanches at the end of the last storm cycle. We have less of an understanding of the progression of these layers east of Mazama and the Twisp River drainage.