Gunnison

Avalanche

CBAC Staff · Nov 21, 2023 · Gunnison

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Weather

CLOUD COVER Clear TEMPERATURE (F) Notable warming NEW OR RECENT SNOWFALL (CM) Sunday's storm: 8 to 20 cm RAIN/SNOW LINE Not Observed SNOW AVAILABLE FOR TRANSPORT Small Amounts WIND LOADING Previous WEATHER SUMMARY Clear, light northerly winds.

Snowpack

Audible collapses and shooting cracks became frequent above 10,800' under slabs of drifted or just subtly wind-stiffened snow. Signs of instability were common on east and northeast aspects, especially on drifted features. The failure layer was consistently the 11/16 facets or faceted crust typically just over a foot deep. No signs of instability traveling on slopes that were bare last week apart from some minor, stubborn cracking in drifted features. 3" of settled storm snow at valley floor increased to about 10" by treeline. Northerly winds have redistributed the storm snow at higher elevations into thicker or thinner areas, some drifts up to 2' thick. At lower elevations, the recent storm snow is starting to facet on colder aspects and melt back to ground sunny aspects, with 1-2mm surface hoar growth on the shady side. Snow surfaces are more wind-affected and rounded higher up.

Avalanche

Numerous recent soft slab avalanches on north to east facing terrain likely failed in the weak, faceted snow leftover from October snowfall (Nov16 facet/crust layer) sometime in the past few days, about 12" to 18" deep on average. A couple of small slabs ATL on a southeast-facing slope appeared to be shallow wind slabs.