Northwest Avalanche Center - Public Observation

Name:

Dallas Glass

Observation Date:

February 22, 2023

Submitted:

February 22, 2023

Zone or Region:

Snoqualmie Pass

Activity:

Skiing/Snowboarding

Location:

Source Lake Area

Comments:

We triggered several small loose dry avalanches in terrain over 40 degrees.

Did you observe any avalanches?

Yes

Comments:

We observed numerous small (D1-1.5) natural loose dry avalanches from steep often rocky slopes. None of the slides we saw were big enough to bury a person.

None reported

Weather: Broken to scattered skies in the morning with prolonged periods of sunshine. Skies became overcast around noon. Temperatures were cold. Winds were light with moderate gust out of the SSE. Gusty winds would drift snow on exposed features and near ridgelines.

Snowpack: New snow depths increased dramatically with elevation. Near the parking lot, we found about a foot (30cm) of very light dry snow over a weak crust. Above 4500ft, that depth increased to well over 2 ft (60cm) over heavier wetter snow that fell earlier during the recent storm. While the new snow was right-side-up, it did fail consistently within the firmer snow about 26in (65cm) below the surface. It appeared like these slabs were falling on a layer of larger rimed grains that probably fell during Monday's warmer weather. This same interface would cause large slab blocks to fail in the corners of some (but not all) up track tests.

Avalanches: There was plenty of older buried debris from the avalanche cycles Monday and Tuesday this week. Most of these slides seemed to fit in the D1.5 -2 range and occurred in the near and above treeline elevation bands. One old larger (D2.5?) slide was observed on the looker's left side of the Great Wall above Source Lake.