Observation Date
12/15/2013
Observer Name
Bruce Tremper
Region
Salt Lake » Little Cottonwood Canyon » White Pine
Location Name or Route
White Pine to upper cirque
Weather
Sky
Clear
Wind Speed
Light
Weather Comments
Clear, warm day with light wind.
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Snow Characteristics Comments
Extremely variable snow conditions, which are typical after a long period of not much precipitation. Some nice, soft, dry faceted snow on the shady aspects below tree line, sun crusts on southerly facing slopes, lots of wind damage above tree line. Total snowpack depth remains shallow with most snow profiles 70 cm or less.
Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Red Flags Comments
Snow strucure remains poor but the overlying snow is rapidly loosing strength and stored energy because of a continued strong temperature gradient metamorphism near the snow surface from the long string of days with clear skies. This continues to rot the overlying slab and the entire snowpack is now composed of faceted snow with the exception of some wind slabs in above-tree-line terrain.
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments
Lots of wind damage in above tree line terrain from both old and more recent winds. There may be some slabs with human triggered potential.
Avalanche Problem #2
Problem
New Snow
Problem #2 Comments
There are likely some places where you can still trigger an avalanche on the deeper persistent weak layers buried about 1-2 feet deep. Most of this activity seems to have died down because enough time has passed and enough TG metamorphism has occurred in the overlying slab to make the whole snowpack much more relaxed and dead. The snowpack seems to be in a dormant state just waiting for the next significant load of weight. Some of the recent wind may be enough to overload faceted snow in the upper elevation, wind exposed terrain.
There's no field for problem #3 but that would be wet avalanche activity on the sun exposed slopes. This problem will just get worse through the week as temperatures warm significantly before our little cold front on Thursday.
Comments
You can see pretty bony conditions on east facing slopes in upper White Pine.
Skiers seemed to put lots of tracks in both Birthday Chutes and Tri Chutes, which are west-northwest facing and they did not seem to trigger anything. People seem to be creeping in to progressively more dangerous terrain--so far without incident.
You can see lots of wind damage in upper elevation, wind exposed terrain, such as here on Red Baldy.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
