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Observation: Big Cottonwood Canyon

Observation Date
11/12/2020
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon
Location Name or Route
Upper Big Cottonwood Canyon
Weather
Sky
Clear
Wind Speed
Calm
Weather Comments
Below normal temperatures overnight and into the late morning. Winds reduced to Calm after over 36 hours of Strong to Intense Winds at the Upper Elevations. Intense sunshine created an appearance of unusual warming from noon on.
Snow Characteristics
New Snow Depth
11"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
HS at and above 8500 feet ranged from 45 cm to 60 cm. Moist layer noted at interface to ground, with a right side up layering in the entire snowpack. Density breaks appeared to have settled out significantly in the past 12 hours.
Trailbreaking was deep and thick in many places, but the challenges with the bottomless unsupportable turning conditions appeared to have improved significantly with the latest snow event. This basing up allowed for excellent riding on slopes with angles greater than 30 degrees, but still a bit slow in the low angle terrain. This issue should improve significantly by Friday with more settlement.
Red Flags
Red Flags
Recent Avalanches
Red Flags Comments
Overall snowpack Structure appears to be unusually strong and rightside up for our region at this time of the season. With over 2 feet of snow falling since last Saturday evening, things appear to be stacking up well. Upper elevation Winds in the past 24 hours have contributed to reports of isolated Slab potential with some activity, but once down in the lower Upper Elevation terrain and lower these issues did not appear to be a factor. The trees were laden with abundant snowfall at and up to usually windy areas from 10,000 feet and down.
Avalanche Problem #1
Problem
Wet Snow
Trend
Decreasing Danger
Problem #1 Comments
Exited in the mid morning hours, yet the Intense Solar observed at 8000 feet in mid BCC from 1100 hours and on indicated that any steep Southerly facing terrain most likely could have had Loose Wet activity in the afternoon hours.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #2 Comments
Reports from the BC indicated that there were Isolated Pockets of Wind Slab activity during the later part of the latest event; and it is Likely that there were areas with lingering Wind Slab Potential from the W to NW Strong Winds at the highest elevations.
Overall the Danger yesterday was Low besides these Isolated issues.
With the forecast for the Winds to increase on Friday (and they have already ramped up overnight on Thursday into Friday morning), the Wind Slab issues will be increasing with the abundant amounts of snow available for transport. This avalanche problem will help elevate the danger on Friday to Moderate.
This combined with significant amounts of precip forecast for Friday evening most likely will escalate the danger to Considerable on Saturday, and possibly High in locations receiving new snow amounts greater than 30 cm or more.
Today's Observed Danger Rating
Low
Tomorrows Estimated Danger Rating
Moderate