Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Recent avalanches: The most recent storm system started on Sunday night, and we have no information about avalanche activity so far due to low visibility. After the last storm on Thursday, there was a widespread natural avalanche cycle in Summit Lake, ranging from large to very large avalanches (D2 to D3). Recent avalanches were observed on Moose Mtn, Roaring Ridge, Manitoba, Butch, and Raven's Ridge.
So far, the current storm is underperforming in Summit Lake, with no precipitation recorded at the Summit Lake SNOTEL site yet. This is inconsistent with weather model predictions, so we don't know if the weather stations are not capturing this storm or if the precipitation is missing the Summit Lake area. Heavy precipitation is forecast today, with 0.5 to 1.0" of water expected. That amounts to 6 to 12" of new snow today above 2500'. Strong east winds averaging 40 to 50 mph will accompany the precipitation.
The generally weak snowpack in Summit Lake could be more reactive to this incoming storm system than the surrounding forecast zones. Recent observations have shown obvious signs of an unstable snowpack, which could lead to natural and human-triggered avalanches 1 to 3' deep if the weather forecast verifies. If this storm ends up being more wind than precipitation in Summit Lake, then the elevated danger will be limited to higher elevation slopes where wind-transported snow is being loaded into start zones.
Due to the existing very weak snowpack, the travel advice remains the same regardless of how the current storm manifests. The best way to manage this problem is to avoid traveling on or below steep terrain. Be aware that you won't always get those clear warning signs, even though the snowpack is ready to produce a big avalanche.
