Observation Date
12/14/2014
Observer Name
Bruce Tremper
Region
Salt Lake » Little Cottonwood Canyon » White Pine
Location Name or Route
White Pine to Spire and into upper bowls
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Speed
Light
Weather Comments
Winter wonderland weather with snowy, frosted trees and light, fluffy snow falling all day. Quite cold in the mid teens but without any wind.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments

Wow, today was one of those days.... Goldilocks powder on a supportable base. About 4 inches at the trailhead with 8 or more inches up high. Very light, stellar clumps falling all day.

Red Flags
Red Flags Comments
No red flags that I could see. New snow does not weight enough to overload any faceted layers. I looked for pockets of wind slab that formed at the beginning of the storm but could not find any on the west side of the canyon.
Avalanche Problem #1
Problem
New Snow
Trend
Same
Problem #1 Comments

I'm still suspicious that there may be other lingering wind slabs on faceted snow hiding beneath the fooffy powder on the surface. The wind blew hard as the storm approached and we've had some both human triggered and explosive triggered slabs involving wind slabs on persistent weak layers. I looked for them quite a bit where I was but could not find any of the Wiley wind slabs. Todd said he found some on the west side of the canyon on Red Baldy and Birthday Chutes. So it's kind of hit and miss with the pre-frontal wind. I'm guessing that these areas are confined mostly to the upper elevation, shady aspects.

Lots of spatial variability with the pre-existing snowpack as is usually the case when it doesn't snow in awhile. The thinner spots are almost all faceted snow where you are sinking to the rocks. In places deeper than about 50 cm there is a stout midpack slab. In thicker areas, the basal depth hoar has gained a lot of strength and is often moist.

Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #2 Comments

The winds were very calm today so with so much very low density powder to blow around, it won't take much wind to create wind slabs in a hurry. The wind is forecast to pick up later on Monday and blow stronger on Monday night and Tuesday with another weak impulse. So watch for building wind slabs later in the day on Monday and especially on Tuesday.

Snow Profile
Aspect
North
Elevation
9,800'
Slope Angle
30°
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate