Observation: Pole Line Pass

Observation Date
12/22/2020
Observer Name
Staples & Meisenheimer
Region
Provo » Snake Creek » Pole Line Pass
Location Name or Route
Pole Line Pass (Midway to AF)
Weather
Weather Comments
Front passing today and very high westerly winds moving lots of snow. 11,000 foot winds nearby on Baldy were gusting to 60 mph at the same time.
Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Collapsing
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
Very weak and faceted snow is on nearly every slope except due south. Areas with slightly thinner snow - sometimes at mid elevations or thinner for other reasons - have the weakest facets which have become striated depth hoar crystals. There is a soft slab about 8-10 inches thick on top of these facets.
Strong winds tonight (Dec 22) and snow fall will increase the danger.
Comments
We rode from Snake Creek up to Pole Line Pass at the divide with American Fork Canyon. Along the road, every steep slope had LONG shooting cracks and had collapsed this weekend when people rode by. See photo below of one of these slopes with cracks that were over 100 feet long. Then we found this avalanche.
It's no mystery what's going on with the snowpack. With all the avalanche activity and collapsing/cracking, it is telling us it is unstable. This is remarkable since it only has about 8-10 inches of snow on top of the facets. It's hardly a slab, but the facets are so weak, we're getting avalnches. Unfortunately the situation is getting worse. Very strong winds today and tonight as well as snowfall will stress these facets and depth hoar even more.
The faceting and weakening will continue - despite snowfall tonight, very cold temperatures are expected through Christmas which will keep the faceting process going.
The snowpit and snow profile of that pit below are very typical of this area.
Video
What about lower elevations? They either have almost no snow or they have VERY VERY weak snow. Because the snowpack at these lower elevations has been so thin, it has faceted even more than higher elevations (thinner snow has stronger temperature gradients).
Below is a snowpit and profile from 8000 feet on a NNW facing slope.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High
Coordinates