Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Recent avalanches: The most recent reported avalanche in the Summit Lake area was on Tenderfoot Ridge on December 28th. Several human-triggered avalanches were observed in Turnagain Pass last Wednesday, many of which were triggered remotely.
The snowfall that started yesterday has added about 4 to 8" of very low-density snow (0.2 to 0.5" water) to the snowpack, with the most new snow in Girdwood and Summit Lake. Anchorage has been the real winner in this storm, with about 15" of new snow at Indian Pass SNOTEL so far (1" water) and more on the way today. Girdwood could also see another 4 to 6" (0.25 to 0.5" water) of low-density snow today, with areas on the Kenai Peninsula expected to get an additional 2 to 4" of snowfall (0.1 to 0.25" water).
This new snow is falling onto a shallow and weak snowpack, with several layers of facets that formed during the prolonged cold snap in December and early January. Even though this storm has not added a huge amount of weight to the snowpack, we expect natural avalanches to be possible and human-triggered avalanches to be likely today on faceted snow about a foot deep. These could fail on facets under a crust (ice crust at lower elevations and wind crust at higher elevations), or on weak faceted snow that was on the surface prior to this latest storm. These weak layers are widespread throughout the Summit Lake area.
(1/5/2026)
Upper elevation snowpit showing new snowfall over weak facets.
Photo: Marc Heifetz