East Slopes South
Avalanche danger
Highlights
Moderate to strong E winds are returning to load atypical aspects. These winds may still be able to move enough snow to create shallow slabs from cold snow remaining on polar aspects. Steer around steep slopes and convex rollovers where you see signs of active or recent snow transport.
Avalanche Discussion
The most recent storm brough 2-6" of snow to the region on Monday. Tuesday afternoon into Thursday, a strong temperature inversion combined with multiple freezing levels, and strong easterly flow are all factors that indicate snowpack variability can be expected by aspects, elevation, and even slope to slope. Thursday saw a switch to mild westerly wind, which allowed warming temperatures to reach the east slopes of the Cascades with temperatures rising above freezing in most locations. The east winds and cold air pool east of the Cascade Crest are returning. The Bumping Ridge SNOTEL stationhas dropped down to the freezing mark as of 5 PM on Friday evening while winds at nearby Pigtail Peak on White Pass are around 30 mph. We think that there is still some cold, dry snow to move around, but not a lot. Expect shallow slab development and watch for similar loading patterns to the slabs that formed Tuesday into Thursday. You might also find older slabs to maintain some reactivity, but there is a significantly lower likelihood of triggering these potentially larger slabs. This OBSERVATION suggests that the older wind slabs were reactive on Thursday in the nearby West South zone near White Pass.
Look for wind loading below fresh cornices rather than old cornices. Steer around pillow-like drifts, and convex slopes orpotentially cross-loaded gullies. Use caution where you see evidence of freshly wind transported snow and navigate around wind-loaded features especially where slopes are greater than 35 degrees.
If the winds relent, some areas may be quite mild. While we don't expect the crusts to break down on solar slopes on Saturday, if they do watch for signs of the snow becoming "heavy" and roller balls or pinwheels forming on the surface. This is evidence that you could trigger a loose wet avalanche. Steer away from slopes in direct sun which are steeper than 35 degrees if you see signs of warm snow surfaces.
During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources. Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.