Deep Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2.5–3.5
Incredibly, Summit Lake received over 4' of snow within one week (between the storms on January 6 and 12), which will be good for this snowpack moving forward. Unfortunately, this created a problem that is deep and difficult to assess. The weak snow that is the culprit of this problem is now 4' or more below the surface and, if triggered, would create a very large and destructive avalanche that would be difficult to survive. The way to completely avoid this is to stay away from steep slopes above 2,500'.
Because this problem is so difficult to assess, we don't know exactly how likley it is that a human could trigger an avalanche of this type. We do know that deep slabs are usually triggered from a thin spot in the snowpack near rocky areas. This problem doesn't tend to give any feedback and it could be the second, third, eighth or ninth skier on the slope that triggers one of these avalanches. If you are getting into steep terrain, safe travel protocols are essential. Travel one at a time and watch your partners. Places that are normally safe may not be when avalanches this large are possible, so factor that in when choosing safe spots.
(1/14/2025)
Very large avalanche on Colorado Mountain that likely occurred during the storm on January 12.
Photo submitted anonymously