Observation: Summit

AAS/AAI Level 3 Travel Day Summary

Time: 8:45 AM to 2:45 PM

Route: Manitoba, up the SW face and then one lap down a northern bowl.

Weather:

Few clouds in the morning, transitioning to partly cloudy, with thin high clouds arriving mid-afternoon.
Temperatures between 10-20f, with light winds from the North at ridge line.

Snowpack:

Thin coverage, with 1-3mm surface hoar above treelike along our route, on all aspects. Snow surface
showed minor wind affect on the main SW face above 2500′, and a thin wind crust was present on
upper North and East aspects. Recent loading has also made small 5-15cm wind slabs on the SW
aspect along the Manitoba ridge line.

Ski penetration varied from 5cm to 15cm throughout the day, with the surface generally comprised of
fist hard near surface facets.

Instability:

No cracking, collapsing, or recent avalanche activity was observed, though the small wind slabs
described above would crack under skier weight, just underfoot.

Three pits were dug at 3,200 feet on N, NE, and E aspects, each showing a similar structure despite
large variation in the height of the snow, which ranged from 100cm to 220cm deep. A profile from the
N aspect is included below, but in general, a thin layer of .5mm rounding facets sits on pencil hard
rounds 30-60cm from the surface, showing medium-high strength in compression tests, no
propagation in ECTs, and medium friction (resistant planar) when failure does occur.