Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
Under the skiff of new snow from last night and winds affecting the surfaces is that Valentine's Day buried surface hoar. This weak layer is buried roughly 1 to 2 feet deep and still reactive in places, darnit. There were two parties out on Tincan yesterday that triggered small avalanches on test slopes (pictured here and another photo below). This is a clear sign it can create a larger avalanche on larger slopes.
If you've been reading along over the last week you'll know this layer caused up to 10 human-triggered avalanches on the backside of Seattle Ridge a week ago (ish). Many of these were triggered remotely (from above or near the slope). The tricky part is, it has shown to be less reactive and not seen on all slopes on the non-motorized side of Turnagain. This makes it really hard to know if a slope is 'OK' or not... For now however, with natural wind slabs and cornice falls happening due to the weather, it's a safe bet to just avoid those bigger slopes, but when the skies clear this issue will make getting onto steeper terrain safely quite tough.
(3/2/2025)
Test slope near the Tincan uptrack avalanched on buried surface hoar about 2 feet deep.