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Observation: Big Cottonwood Canyon

Observation Date
2/21/2023
Observer Name
Hardesty
Region
Salt Lake » Big Cottonwood Canyon
Location Name or Route
Lower Days Fork > West Ridge of 10420
Weather
Sky
Overcast
Precipitation
Moderate Snowfall
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
Prefrontal environment. Rain/snow line roughly 6000'.
Snow Characteristics
New Snow Depth
4"
New Snow Density
Low
Snow Surface Conditions
Powder
Red Flags
Red Flags Comments
None currently. Minor sluffing in the new snow; I left the canyon mid-afternoon prior to frontal passage.
Avalanche Problem #1
Problem
New Snow
Trend
Increasing Danger
Problem #1 Comments
If forecast snow totals verify, we'll see both natural and human triggered avalanches on many aspects AND elevations Tuesday night into Wednesday.
I went looking for the surface facets that formed last week during the cold and clear. On polar aspects, they are buried a couple inches deep beneath the weekend snow and today's snow. The last day or two of warmth and - in some areas - greenhousing has allowed these facets to gain some strength and they do not look as loose as they did. The weakest snow I found today was within the new snow and it was sluffing easily - running fast and far - on steeper slopes.
My greatest uncertainty is with the low elevation structure that similarly holds these faceted grains and I worry that some low elevation avalanche hazard will surprise people unaccustomed to seeing it. The video probably overplays the situation, but it should be on people's radars to view as guilty until innocent.
Photo shows clean layer of faceted grains that are not all that weak on a north facing slope at 9650'. My best guess is that avalanching will occur with the heavy snowfall and wind and may step a few inches into this layering in some areas.
Video
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
None
Coordinates