Snoqualmie Pass

Windy conditions Wednesday could build a fresh set of shallow slabs on the lee side of exposed ridges and rocky features. Be leery of smooth pillow like drifts where you see blowing snow and underneath sharp cornices.

We’ve been stuck in a rinse-and-repeat weather pattern most of the week. Some patches of blue sky in the morning should lead to increasing clouds and snow showers in the afternoon. Even with the possibility of a few inches of snow, it shouldn’t have much bearing on the avalanche danger. 

We think cloudier skies in the afternoon and a thin crust on southerly aspects will limit any loose wet avalanche concerns. However, if you experience prolonged warm sunny weather, snow may start to shed from rocks and trees. This could result in some piles of new rollerballs and maybe a few small loose wet avalanches. Indeed, observations from this week at the Pass, show a few isolated wet slides from brief periods of sunshine. 

On more shaded aspects, the upper snowpack is still very soft, dry, and right-side-up. Recent avalanche activity has been mostly limited to a few small natural and triggered wind slabs and loose dry avalanches. Two larger (D2-2.5) avalanches buck that norm. On Monday, an avalanche professional spotted a deeper (~3ft/1m) natural slide in the Chair Peak Lake Basin (E, 5600ft). This slide may have failed on the 2/25 interface. A similarly deep avalanche occurred last Friday when an intentionally triggered small wind slab stepped down to a deeper (2.5ft/80cm) layer (N, 4300ft). While similar avalanches seem unlikely given the current weather pattern, we can’t rule out an isolated large avalanche in sheltered shaded terrain. It may take a  larger trigger like falling cornices, other avalanches, or snowmobiles to impact these deeper snow layers. Take this into consideration before venturing into bigger more consequential terrain.