Observation: 10420

Observation Date
12/28/2017
Observer Name
Evelyn

Region:

Location Name or Route
10,420'
Weather
Sky
Clear
Weather Comments
Winds were light...none low down, only a slight breeze at the top. Temperatures were warm, especially in the sun, into the low 30s.
Snow Characteristics
Snow Surface Conditions
Powder
Wind Crust
Damp
Snow Characteristics Comments

Still very nice, settled powder on shady, sheltered slopes.  Wind damage seemed minimal.  The snow is more supportable now, and coverage is enough you can get around and avoid most fallen trees and stumps.  Sunny slopes were damp, and will be crusted tomorrow.  Surface snow is starting to facet and weaken, with only a little surface hoar.

Red Flags
Red Flags
Collapsing
Poor Snowpack Structure
Red Flags Comments
Small to medium collapses were felt, but you really had to get away from the old trails and tracks. And they definately weren't every slope. Snow pits on northelry facing slopes had all the well documented weak layres. No change there.
Avalanche Problem #1
Type
Persistent Slab
Problem #1 Comments

I have to say I was quite surprised - no evidence of natural avalanche activity that I could see, on either 10,420' or Clayton Peak.  Parts of the northeast face of 10,420' were tracked by skiers/borders without triggering slides.  Snowmobilers had traveled under and part way up some of the steep, northeasterly facing sides of both peaks with no issues.  This is the same aspect and elevation of the recent slide on Jim Klem.

Perhaps there were some slides that occurred during the first blast of snow on December 23rd, and the evidence is covered.  An ECT on a north facing slope at 9,200' fractured, but did not prorogate across the column.  

My bottom line:  while the facet layers in the snowpack seems to be gaining strength, I still would avoid steep northerly through easterly facing slopes - the chance of triggering a slide is still too great, and if you do trigger a slide, it won't be any smaller.

 

 

Avalanche Problem #2
Type
Wind Slab
Problem #2 Comments

Wind slabs (shallow, 1 Finger) seem to have settled out in this area, and I couldn't get any of them to crack or collapse.  The winds while I was out weren't strong enough to transport any new snow.  

Comments

Quite a difference in snow coverage between December 19th and today, December 28th.  Snow that fell between the 21st and 25th has covered a lot more terrain.  Also, with the current dry weather forecast, more faceting will occure in the newest snow. 

The photos below show how difficult it may to determine now where the older snow is, and where it's not, and how that can change over such a short distance.  

Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Snow Profile Coordinates