Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
February 26, 2022
Submitted:
February 26, 2022
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
West South
Location:
East Peak/Cement Basin (Most aspects near treeline. )

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

Snow profile from Cement Basin near Crystal Mt.
1mm Facets found between the 2/19 and Valentine's Day crusts.
Sovel tilt test from snow profile in Cement Basin near Crystal Mt.
Facets below a breakable sun crust on East Peak, near Crystal Mt.
Surface Hoar was seen on some shaded slopes and at lower elevations.
Intentionally triggered small wind slab on an E aspect near the top of East Peak. (HS-ACc-R1-D1-S, 6-8" deep, E, 6600')

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Wind:
Moderate , S
New/Recent Snowfall:
Trace

Generally broken skies with periods of filtered sunshine today. The clouds kept the sun from softening the snow surface. Winds were the big story. Moderate to occasionally strong ridge-top winds from the S were the norm. However, below ridgelines, winds were noted from nearly every direction. Some blowing snow did occur at ridge crest, but was minimal and not enough to create new wind slabs.

It started snowing about 2:30pm, but only a trace of new snow during the day.

I was able to trigger 2 very small (D1) wind slabs on E aspect on Cement Basin using intentional cornice drops. These slabs were approx. 10ftx10ft and 6-8inches deep. Other than these two tiny wind loaded pockets, we did not find any other avalanches.

Snowpack Observations

We were out today mainly tracking snow surfaces and checking the 2/19-Valentine's Day Crusts ahead of the storm.

Upper elevations: Near ridge crest, every aspect shows significant signs of wind-affected snow from the past week. Sculpted snow, textures surfaces, scoured slopes, and very small firm drifts covered most large startzone.

Below Ridge Crest, the snowpack was much more aspect dependent.
Sunny Slopes (E-S-W): A variable sun crust form this past week (2-8cm thick) was very prevalent. In most spots this crust is breakable. Small facets were found underneath this crust in many spots. These facets failed very easily in all tests. The 2/19 and Valentine's Day crust have melded together into on very strong melt-form layer about 6-8" below the surface. The snow is well bonded to this crust.

Shaded Slopes: Surface hoar and preserved large stellar were seen on some shaded slopes. The surface hoard was generally small (3-5mm) but up to 7mm was observed. About 8-10" of soft unconsolidated snow from last weekend's storm capped the 2/19 crust (<1cm thick MFcr). Well angulated facets (1-1.5mm) were observed between the 2/19 and Valentine's Day crust. These weak grains failed in small column test just below the 2/19. However, they did not show signs of propagating in large column test likely due to the lack of a slab above them.

While we could still make out the Late January crust, it has weakened significantly and is barely decernable.

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