UDOT PLANNED AVALANCHE CLOSURES!!

Observation: Neffs

Observation Date
1/15/2014
Observer Name
Bruce Tremper and Cody Hughes
Region
Salt Lake » Neffs
Location Name or Route
Neff's Canyon - main canyon to Neff's Pass
Weather
Sky
Clear
Wind Speed
Light
Snow Characteristics
New Snow Density
Low
Snow Surface Conditions
Faceted Loose
Snow Characteristics Comments

Quite good turning conditions in dense, supportable, near-surface faceted snow and surface hoar. Southerly facing slopes are bare or damp.

Red Flags
Red Flags Comments
No real red flags in that area.
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments

I was curious about the snowpack in Neff's Canyon because it's often thinner and weaker than other areas in the SLC area mountains. But I found that it was relatively deep and stable. In shaded slopes a couple hundred vertical below Neff's Pass (about 9,300') the snowpack was 130 cm deep and my snowpit showed quite stable snow with any faceted layers buried deep enough that they are probably gaining strength fairly quickly. There was also a thicker, stouter slab of new snow on top, which appeared to be lots of rimed snow with some wind drifting.

In another snowpit around 8,500' on a northerly facing slope in a wind-sheltered area, the total snowpack depth was 100 cm, thinner and weaker and on compression tests, it was mushing down on a graupel layer about 40 cm deep with CT13 and then it would occasionally break on a thin layer of mature depth hoar near the ground with hard taps articulating from the shoulder. In other words, the snowpack seemed fairly stable.

No other signs of instability in that canyon. I did not look at any of the more extreme terrain and, as always, the snow is usually weaker and more unstable on the steep, rocky terrain. But in general, I would call the danger in that part of Neff's where we were Moderate danger.

It seems to me that the main problem areas are where the strong wind has loaded a significant load of snow onto a faceted snowpack that can barely support the weight. I have a feeling we are at that stage in the winter, which happens most every year, where the snowpack in the central Wasatch is thicker and more stable than places with a traditionally thinner snowpack in the early season, such as Logan, Uintas and Manti Skyline. At least they have certainly had more avalanche activity than the central Wasatch.

I'm still thinking an overall Level 3 (Orange, Considerable) danger for the Wasatch Range because of those thinner areas with recent wind deposits in these last few days. But in most other areas the danger may be lower. I have not been able to do many field days lately, so I'm just going mainly on other observations and my gut feel from lots of experience.

I may add a profile and video later if time allows. It's getting late...

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