Observation Date
12/1/2018
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter
Location Name or Route
Brighton/Mt. Millicent/Wolverine/Lake Martha
Weather
Sky
Overcast
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Winds appeared to have died down late in the evening on Friday and throughout the day on Saturday remained light with no wind blown and or transport observed. Skies were mostly clear/few in the morning with increasing cloud cover in the afternoon. By 1400 the skies were overcast. Temperatures were warm enough combining with the solar to cause south facing slopes (even at upper elevations) with angles greater than 20 degrees to get damp during the latter part of the morning hours, and subsequently there is a zipper crust now on these slopes.
Snow Characteristics
New Snow Depth
5"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments
13 cm overnight of moderate density snow due to the winds, and sustained storm totals from mid week are now at least 50 cm. Of note, in the mid elevation protected areas the upper 10 cm of new snow was very light. West facing slopes had a bit of wind damage, and some upper elevation north aspects did as well. Besides this, it was superb powder riding from the peaks down to the trailhead.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Poor snowpack structure appears to be an issue that will be with us for some time forward. Of note, one of the steep skiing Wasatch Legends was spotted riding only low angle terrain today and his comments when approaching a steep line were pronouncing it was too bold of a line for the conditions we are experiencing. See rest of the observation for details on the rest of the red flags.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
Of note, huge and booming collapse experienced on descent down the Wolverine Sneak Exit, and this occurred 15 feet above a preexisting skin track from the morning. Reports from the individual that made the ascending skin track up to Wolverine indicated they had not experienced any collapsing on their route. Collapsing was experienced on an ESE aspect with a slope angle of 35 degrees and an elevation of 10,000 feet. Collapse was heard from a significant distance and radiated out down slope and at least 100 feet from triggering point. Slab appears to be stiffening significantly with the additional load and wind distribution.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #2 Comments
Overnight activity noted in avalanche report from Millicent and Brighton Back Bowls, along with reports from Cardiac Ridge/Ivory, appear to validate the significant natural activity that occurred during the high PI and wind event on Friday evening. These wind slabs appeared more stubborn on Saturday, but with the underlying persistent weak layers in the snow pack, this problem may linger and noteworthy still on Sunday.
Comments
Due to the lack of natural activity out there today, the danger appeared to be a very high consequence Moderate, and Sunday's may remain the same if the winds and new snow totals do not ramp up much past their forecast values.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
