Observation Date
1/24/2017
Region
Salt Lake » Big Cottonwood Canyon » Brighton Perimeter
Location Name or Route
Brighton Periphery
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Overcast Skies the majority of the day with periodic times when it was Obscurred. Winds on the exposed ridgelines were out of the West and sustained in the Low End of the Moderate Range. Wind Blown and Transport was in Moderate Range, and Loading Leeward Slopes below ridgelines as well as building Cornices. Temperatures remained cold and in the mid teens at Upper elevations. Light Snowfall was intermittent throughout the day at Sminus1.
Snow Characteristics
New Snow Depth
7"
New Snow Density
Low
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments
Storm Totals in mid BCC since Wednesday the 18th: 48 inches. Last part of this event saw 30 inches fall from Sunday early evening through Monday early evening. Incredible powder riding today. The last wave of the storm overnight dropped another 7 inches of Light Density Snow with very little wind. As a result the Intense snowfall that occurred throughout the day on Monday served as a supportable base that was bottomless. Wind Scuplting and Sastrugi was observed on the the Windward/West/Southwest exposed upper elevation ridgelines.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Poor Snowpack Structure
Red Flags Comments
The remotely triggered slab that was reported from the Park City ridgeline indicates that there is still a propencity for Propagation within the multiple layers accumulated over the past week. Obviously, Heavy Snowfall and significant Water Weight has possibly overburdened buried weak layers in the upper meter of the snowpack. Despite this possible potential, no Avalanche Activity was observed in the Brighton Periphery, and many steep lines were ridden on various aspects.
Avalanche Problem #1
Problem
New Snow
Trend
Same
Problem #1 Comments
Cornices were easily triggered and dropped on steep slopes on Claytons and the 10420 ridgeline with only Loose Dry Snow Avalanches/Sluffs running from these interventions. On the 10420 ridgeline in the Lane's Leap area Cornices the size of mini vans were released and these gouged Loose Snow Avalanches running within the New Snow up to 12 inches deep. Steep riding also was initiating Loose Snow Avalanches, and these were only in the upper 8 to 12 inches of New Snow.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Same
Problem #2 Comments
Wind Slabs appeared to be non-reactive today. The Avalanche on the Park City Ridgeline indicates that the Persistent Slab Problem is not dormant.
In areas traveled today the Danger appeared to be in the Moderate Range; and with no significant additional water weight and or wind to increase the Danger for Wednesday it appears it will be Moderate.
First picture Cornice Release on 10420 ridgeline with resulting Loose Snow Dry Avalanche. Second photo Lane's Leap Natural that appeared to have occurred during the Intense PI on Monday. Third picture, the only Natural observed on Tuesday: Roof Avalanche that occurred around 1300 hours. Of Note: there was no warming and or sun, and this appeared to be a result of buried weak layers at the interface as there was no wet component to the triggering.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
