Observation Date
2/5/2021
Observer Name
Trenbeath, Groves
Region
Salt Lake » Little Cottonwood Canyon » Alta Periphery
Location Name or Route
Point Supreme - Rocky Point
Weather
Sky
Obscured
Precipitation
Heavy Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Moderate snowfall, at times heavy, and at times difficult to discern whether or not it was actually snowing or just blowing. Most of the snow fell between 1100 and 1600 hrs. Westerly winds were mostly moderate but with stronger gusts and were actively transporting snow.
Snow Characteristics
New Snow Depth
10"
New Snow Density
Low
Snow Surface Conditions
Powder
Dense Loose
Snow Characteristics Comments
Dense drifts up to 2' deep were forming along leeward ridge crests along with fresh, semi-sensitive cornices. Slabby conditions were developing on top of the low-density snow that fell yesterday.
Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Cracking
Red Flags Comments
Active wind loading was resulting in slab formation but cracking was isolated and things were not overly sensitive on the surface. We dropped a few cornices with no results, and we ski cut across the top of a few chutes that we felt we could safely manage without result, the main point being "that we felt we could safely manage." With so much wind loading going on, and with a known persistent weak layer problem, we weren't willing to venture off of ridge crests and I feel that the slightly stubborn nature of fresh wind slabs would only serve to lure one further on to the slope before they released.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
This is a known problem and the additional snow load is only stressing it more. I and anyone I know will continue to avoid slopes steeper than 30 degrees on slopes facing W-N-SE, additional snow load notwithstanding.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
Active wind loading was forming fresh drifts up to 2' deep on top of low-density snow that fell the day before. Previous comments describe the condition and behavior of these wind slabs but deep and dangerous drifts have formed on all leeward slopes.
Comments
New and wind drifted snow has exacerbated already dangerous avalanche conditions and this should not be understated. Human triggered avalanches up to 2' deep involving fresh deposits of wind drifted snow are likely. Additionally, the new snow load has increased the likelihood of triggering deeper and more dangerous avalanches on buried persistent weak layers of faceted snow.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates
