| Recent Avalanches? | No |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | No |
Observation: Summit
Location: Summit Lake - Fresno
Gained the southeast ridge and skinned to 2800′.
Obvious signs of instability
Observer Comments
We got two big collapses at 2750' in a particularly thin area (total snow depth 50-75 cm). Collapses were failing in the facets at the ground, and one of them felt like it propagated a few hundred feet.
Weather
We had a good window of visibility once we got above the valley cloud (around 2000'), but high clouds moved in and everything went flat by about 2:00. Wind was calm, with no snow. Air temp was 10 F at 2600' at 1:30.
Snow surface
Below 2500': 2-4" dust on supportable crust made for good riding conditions.
Above 2500': 4-5" dust on settled powder. Great skiing!
Snowpack
Supportable crust up to 2500', with snowpack about a meter deep at 2600'. Still finding basal facets at the ground, and we got some big collapses failing in this layer at around 2750' in some areas with a thin (50-75 cm) snowpack. For now, the facets at the ground are the primary concern. Starting to see surface hoar and near-surface facets at the surface, which will be an issue with new snow.
Pit at 2,600', snow depth 100-115cm
ECTP 22 on basal facets. Facets were moist, but when the block failed the facets jumped right out and the block dropped an inch.
Some other notes from the pit:
-Starting to see some faceting above and below the new surface crust.
-Layer of buried surface hoar 30 cm off the ground was unreactive in stability tests.
Summit Lake. Hand pit at 2300'. About 4" new snow sitting on a 2" thick crust. 12.04.2020.
Summit Lake. Isolating a column for a stability test that would fail in a weak layer of facets at the ground. 12.04.2020.
summit lake pit