Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Recent avalanches: There have been multiple observations of remotely triggered avalanches in the Turnagain Pass zone, including Repeat Offender, Lynx Creek, Tincan Common, Eddie's Headwall, Main Bowl, and near the weather station on Seattle Ridge. No recent avalanche observations have come in from Seward and Lost Lake yet, but the weak layer setup is very similar to Turnagain Pass.
The dangerous snowpack setup that caused all the recent avalanches in Turangain Pass also exists in the Seward and Lost Lake area. There is a good chance of triggering a very large avalanche 1 to 3' deep on a layer of facets that formed during the December cold spell. The size of these avalanches and the fact that many of them are being triggered remotely, from low-angle terrain adjacent to steeper slopes, make them extra scary. With this setup, accidentally triggering an avalanche from low-angle terrain below a steep slope and being buried in the runout zone is a very real hazard.
The only way to safely manage this situation is to stay off steep slopes, avoid runout zones of overhead avalanche paths, and be very mindful of terrain traps that could cause a deep burial even from a small avalanche. Patience is very important with this type of persistent weak layer, because they often take weeks or longer to become less dangerous. The major storm we are expecting on Thursday could stress the snowpack to the point where we see widespread natural avalanches and potentially help reset the snowpack. We will have to wait and see, but in the meantime, we can't stress enough how dangerous this setup is.
