Professional Observation

Basic Information

Observation Date:

January 14, 2022

Submitted:

January 14, 2022

Observer:

Brooke Maushund | Pro Observer

Zone or Region:

June Lake

Location:

Yost Creek to Fern Grotto

Recent Avalanches?

None Observed

Cracking?

None Experienced

Collapsing?

None Experienced

Stability Rating:

Good

Confidence in Rating:

High

Stability Trend:

Worsening

No signs of instability observed in Yost Creek drainage to Fern Grotto
Surface conditions were variable, from punchy crust, to wet snow, to completely locked up firm surfaces — icy at times
While avalanche hazard was not a major concern today, travel conditions both up and downhill warrant caution. A slip and fall without proper self-arrest gear and technique could mean high consequences even on a seemingly unintimidating slope. Ski & boot crampons, along with an ice axe are not unwarranted. Knowledge of how to use them is just as important as carrying them.
Very little snow available for wind transport

Firm surfaces in the flats of Yost Creek

Debris from recent wind event and evidence of past shedding snow from trees

Punchy solar crust observed on E shoulder of Yost Creek with soft, rotting snow beneath

Skinning conditions on Hemlock Mountain were challenging, varying from completely locked up icy surfaces to a thin crust depending on how you wrapped around the ridge.

Fern Grotto at sunset after a quick sketching stop

Advanced Information

Cloud Cover:

Mostly Cloudy

Temperature:

0°C

Wind:

Calm

Toured out of the 4 Seasons parking lot up Yost Creek at 1340 for a sunset tour. On the flats leading up to the canyon, sky cover was BKN though temps were well above freezing as I was down to my base layer almost immediately. The surface was icy but supportive, with past wind effect evident (see photo 1). HS 112cm in flats at 7495′ elevation along Yost Creek. Traveling up along the creek until peeling to E side, evidence of both our past extreme wind event and warm temps could be observed in the debris in the canyon on the snow surface and the lack of remaining snow on most trees (see photo 2).

Traveling along the E side of the creek on a W aspect, the snow surface was extremely variable for skinning: almost warranting ski crampons down low in the shade, and wet/warm with the afternoon sun exposure higher up, providing low coverage in certain areas and a definite solar crust over rotting snow in other areas (see photo 3). At 1414, at 8340′ along this slope, HS was 72cm, and temps were still well above freezing in the sun. Topping out the bench that brings you towards Hemlock Mountain and Yost Lake, at 1444 at 8826′, HS was 98cm, with wind effected snow becoming evident and temps dropping below freezing cresting over the ridge.

The final part of the tour from the bench up Hemlock Mountain provided very consolidated snow with surfaces that warranted ski crampons for the remaining skin to the top of the couloir. Winds remained calm throughout the tour and cloud coverage remained BKN though thin.

Surface conditions were variable throughout the tour, with modestly surprisingly soft snow throughout the forest of the lower toe of Hemlock. The upper reaches of Hemlock Mountain though provided the most challenge: varying between a very thin crust over soft snow and completely lock up surfaces. Skinning was character building, and I was happy to have ski crampons for the remaining uphill. Once reaching the rocky ridgeline past the trees for the final stretch, I switched to booting & scrambling on the rocks, which luckily the snow provided an excellent surface for kicking steps. Conditions in Fern Grotto were moderately better than expected (with extremely low expectations), though threading the needle on the middle roll of the couloir through rocks is not for the faint of heart right now (or those with new skis). While the sunset sketching was much more enjoyable than the skiing, still a worth outing with the right equipment.