Observation Date
12/14/2016
Observer Name
Greg Gagne
Region
Salt Lake » Little Cottonwood Canyon » Grizzly Gulch » Twin Lakes Pass
Location Name or Route
Twin Lakes Pass
Weather
Sky
Overcast
Precipitation
Moderate Snowfall
Wind Direction
West
Wind Speed
Moderate
Weather Comments
New snow is dense with rimed crystals.
Snow Characteristics
New Snow Depth
2"
New Snow Density
High
Snow Surface Conditions
Powder
Wind Crust
Red Flags
Red Flags
Recent Avalanches
Cracking
Poor Snowpack Structure
Red Flags Comments
Will comment below.
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments

Persistent slab weaknesses in the mid pack and near the surface. This morning I noticed the new snow was not bonding to the old snow surface which had become faceted. Not enough new snow as of yet to cause a concern, but with quite a bit of new snow and water weight expected late this week, this is a weak layer currently down 5-10 cms (2-4") that we will have to watch.

Comments

To quote Nobel laureate Bob Dylan, "I can't help it if I'm lucky." Got lucky and found a weak layer with touchy conditions this morning.

Went out for a quick lap up to Patsy Marley, and was interested in how the new snow was bonding to the old snow surface. Shovel tilt tests were getting clean shears at the old snow interface indicating a poor bond. Had my scope with me, but with new snow falling and some wind, hard to determine the type of weak layer. Likely small-grained near surface facets, or decomposing fragments turning to facets. With very little new snow (5 cms/2") currently not a concern, but with storm totals by Sunday expected between 1-2' with perhaps 2" of water weight, this is another persistent weak layer in our snow pack we will have to watch.

Moving along the ridgeline from Twin Lakes Pass to Patsy Marley was finding very sensitive conditions with fresh soft wind slabs easily cracking just as you tapped on a slope, or dropped a small cornice. These were shallow (5-15 cms/2-6") and soft (at most 4F), but they were failing at the old snow/new snow interface. The widest was about 120'. Most interesting was a tiny 30 cm (1') cornice drop that fractured a shallow wind slab which sympathetically pulled out another slab on an adjacent slope.

Poor quality, but photo and two videos from my short tour describing what I was seeing this morning.

Video
Video
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate