Snoqualmie Pass

Cloudy skies, mild temperatures, and minimal new precipitation should keep the snowpack strong and help limit the avalanche danger at Snoqualmie Pass Monday. That doesn't mean you can’t find unstable snow in a few very isolated areas. Keep your eyes peeled for clues you are in one of these unique locations.

Generally clear skies most of Sunday night should allow the wet snow from this weekend to freeze. The weather we’re expecting on Monday likely won’t be able to break down any surface crust nor cause lingering pockets of dry snow to become unstable. While temperatures should be above freezing, without the help of the sun, the snow surface probably won’t soften significantly. Windy conditions will further help cool the snow and prevent it from weakening. Finally, we’re not anticipating much in the way of precipitation at the Pass. So, even when it falls as rain, it shouldn’t create any wet snow concerns. All this leads to a generally strong snowpack. Because the avalanche hazard hinges so significantly on the weather forecast if you find more rain or fewer clouds than anticipated the danger may be rising. 

While the wind will help keep the surface cool, at upper elevations, it may drift some of the recent snow into shallow slabs. Fortunately, after a few warmer days and several rounds of wind this past week, there isn’t much snow easily available to blow around. This will limit the size and distribution of this possible problem. If you notice smooth firm pillow-like drifts, steer around these features on steep slopes. 

If the snow surface manages to become wet, whether due to rain, temperature, or sunshine, start anticipating loose wet avalanches. Often new rollerballs are a great clue that the snow surface is approaching this tipping point. When you see this observation be leery of similar steep slopes. 

While we are expecting low avalanche danger on Monday, the snowpack still has a weak structure. The Late January crust/facets can be found at the base of the recent snow in some locations. This layer is most prevalent on shaded slopes. Typically a thin melt-freeze crust caps a few inches of small weak facets or facets sit just above a slightly thicker crust. So far we haven’t heard of any avalanches on this layer at Snoqualmie Pass and snowpack tests have given inconsistent results. However, in zones further north, several avalanches, large collapses, and sudden test results continue to occur. We’ll keep our eye on this layer going forward.

Recent weather created a highly variable snow surface. Even with the warm and sunny weather this weekend, cold and dry snow persisted on shaded slopes. On Monday, you’re likely to encounter breakable crusts, icy slopes, heavy wet snow, wind textured surfaces, and pockets of cold dry powder as you travel.