Observation: Summit

Location: Fresno and Tenderfoot

Date:
Observer:
Route & General Observations

Two groups of Pro 2 avalanche students went out to collect observations from Tenderfoot and Fresno. Their impression of the zone follows: Summit Lake holds a shallower and weaker snowpack than the central part of Turnagain Pass. Currently very little snow and rain has fallen there, so the primary areas to are heavily wind loaded features near treeline and above. The best skiing exists above the rainline ~2000′ and below the alpine in sub 35 degree terrain in non-wind-loaded areas. Isothermal goo exists below 2000′ and will be truly delightful once it freezes.
One recent natural avalanche was observed on a peak close to Tenderfoot where the crown line was in the alpine ~3000′ and the debris ran down to the saturated snow in the run out. The crown was hard to detect in this heavily wind loaded west aspect, but the debris was estimated to be D2 in volume. No other (confirmed) recent activity was visible in the filtered light of the day.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?Yes
Observer Comments

shooting cracks up to 20cm deep and up to 15 meters long (8" x 50') on wind loaded features - typically much shorter - no movement on test slopes up to 43 degrees. these cracks occurred typically between 2300' and 2800'.
Localized (within the length of the skis in the isothermal goo near the highway. Just the wet basal facets collapsing in non-skied terrain.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.
Weather

No precip. Broken to overcast skies. Light to moderate winds from the North. New snow totals in non-wind loaded terrain around 2500 was ~10cm (4") over the 1/21 SH.

Snow surface

Wet snow to Moist snow from 1200' - 2200'. dry above. Above 2800' on the Fresno ridge line scoured areas held facets, large facets and small depth hoar - all from being a shallow snowpack in the alpine.

1/21 SH and NSF was 10-20cm down above 2400’. In alpine at 3450’ a rime crust had actually formed on top of the SH.

Snowpack

No propagating results in any pits .