Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Recent Avalanches: A snowmachine triggered an avalanche up Lynx Creek on Sunday and was caught and carried. There was a human triggered avalanche on Seattle Ridge over the weekend where a person was caught and deployed their airbag. Another human triggered avalanche was reported in the Eddie Trees on Sunday. It was described as having a lot of energy and moving to lower angle slopes. There were also multiple reports of small avalanches yesterday on Tincan and Seattle Ridge that were being triggered in the new snow about 1’ deep. These may be small but have the potential to trigger a deeper avalanche.
Conditions remain dangerous as multiple human triggered avalanches are occurring almost everyday. These are failing on a reactive layer of surface hoar buried up to 3’ deep on all aspects above 1500’. This layer is not gaining strength quickly which is obvious due to the large amount of human triggered avalanches. Around 12” of storm snow has increased the size of these avalanches and the chance of a human triggering them. A lot of these have been triggered remotely meaning that you can be traveling on a low angle slope and trigger an avalanche above you. What is also concerning is that travel tests can produce stable results on a dangerous slope making it seem safe and then the slope you are skiing avalanches. It is also possible that a smaller avalanche within the new snow could step down to the buried surface hoar layer, releasing a large avalanche.
This weak layer should not be underestimated. It has been responsible for many human triggered avalanches. The mountains are telling us that the cards are not stacked in our favor. We recommend choosing conservative objectives as this problem is dangerous and extremely difficult to assess.
Dry loose snow avalanches are likely due to the light snow that fell on Sunday. Wet loose avalanches will be easy to trigger on sunny slopes and have been large enough to carry someone where they do not want to go (into trees or off cliffs).
Look out for cornice falls today on slopes above you. It is likely that they will trigger a large avalanche above you. Try to avoid spending time under them and give them a lot of room on ridgelines.
Glide cracks continue to open and can release into a large glide avalanche at any time. These are spontaneous events and can be large and destructive so try to avoid spending time under them.
