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Observation: Big Cottonwood Canyon

Observation Date
4/2/2020
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon
Location Name or Route
Upper BCC
Weather
Sky
Few
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Early morning mostly clear skies gave way to OVC by 1200 hours. Patches of solar with sucker holes occurred periodically in the early afternoon. Unseasonably cold temperatures persisted into the early afternoon hours upon exiting. S-1 snowfall began around 1400 with little to no accumulations. Light WNW Winds were blowing in the morning hours, and at 1200 hours they appeared to veer more out of the West and gained significant strength. These winds were initially observed only on the ridgelines, and then they became more apparent down to at least 9700. Scouring and subsequent Moderate transport was observed with isolated one finger Wind Slabs being created. Minor cracking was observed in the more protected areas traveled.
Snow Characteristics
New Snow Depth
5"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Damp
Snow Characteristics Comments
Lack of any significant overnight winds below the upper elevations ridgelines had the snow surface covered with an even blanket of undisturbed stellars in the morning hours. Yet, by 1200 the winds began to damage much of the snow in the all Upper Elevation exposed areas down to 9700. No solar damage was observed in the Upper Bowls as late as 1400 hours. Once below 9300 feet the intense April sun dampened the snow on all aspects. Fortunately the frigid overnight temperatures froze the pre-storm snow surface, so there was excellent supportable riding all the way down to 8700 feet.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Red Flags Comments
Minimal/manageable Loose Dry was observed on any terrain ridden that was steeper than 35 degrees. A Natural Loose Dry Cycle was observed around 1245 hours (see avalanche report). Moderate to Strong Wind Blown and or Transport was observed from 1200 and on. Small isolated pockets of one finger Wind Slab were observed with some cracking noted.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
See above and this issue was obviously more of a likely problem in the Upper Elevation exposed terrain; and it's trend was increasing throughout the day. Combining this issue with the slick/firm bed surfaces out there. and last nights light density snow may allow for small Wind Slabs to entrain significant amounts of snow when descending confined terrain features like narrow steep chutes.
Avalanche Problem #2
Problem
Wet Snow
Trend
Increasing Danger
Problem #2 Comments
In areas traveled at and above 9500 feet this issue was minimal, yet roller balls were observed on steep ESE, S and SE aspects even in these higher elevations. It was likely that any travel in the mid elevations saw this problem be more of an issue. And, in any areas where the solar was more of a presence, this issue most likely would have become active during the mid to late afternoon hours despite the cold temperatures. Fridays forecast for rising temperatures and sunny skies will likely increase the possibility of this problem.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate