Ad
The National Forest Service Logo
icon-add Observation
Forecasts
Logan Ogden Salt Lake Provo Uintas Skyline Moab Abajos Weather Archives How to read the forecast
Observations & Avalanches
Submit Observation Observations Explorer All Observations Avalanches Fatalities Weather Place Names Map Archives
Education
Avalanche Class List UAC Class List Online Classes Resources and Tutorials Avalanche Awareness Develop Skills
Events
Store
About
Contact Who we are Core Values Staff Board of Directors Past Forecasters Sponsors Annual Reports Sign In
Blog
icon-add Observation
Donate / Join

Observation: Park City Ridgeline

Observation Date
12/23/2014
Observer Name
Toddeo
Region
Salt Lake » Park City Ridgeline
Location Name or Route
Beartrap/West Willow/PC Ridge
Weather
Sky
Clear
Wind Speed
Light
Weather Comments
Cold in the shade.
Snow Characteristics
New Snow Depth
10"
New Snow Density
High
Snow Surface Conditions
Dense Loose
Rain-Rime Crust
Snow Characteristics Comments

4 to 10". 4" over a stout rain crust at the TH. Mostly graupel. Ridge tops are scoured to a rime crusts in place. Snow pack is generally supportable with minimal ski penetration. Underlaying crust generally disappears at 8500' on north aspects. Of note is that the whole snow pack fails with a ECTP11 in the basal facets (see profile). One other shear (Q2) was located at a graupel layer at the base of the most recent storm snow. This is stubborn but is of a concern (see profile)

South aspects contain up to 14" of soft snow overlying a stout sun crust. I was able to observe some preserved surface hoar about 3-4" above the crust in one location. The surface hoar is not very reactive, it took a good push to get a moderate to poor quality shear Q2/3. This might be worth keeping an eye on.

Rime crust is exposed at wind scoured ridge top locations.

I was not able to see the avalanche reported in Dutch's, it must have blown in.

Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Collapsing
Poor Snowpack Structure
Red Flags Comments
With the exception of a couple of minor collaspes and the West Willow Slide (photos) you had to look for red flags. It is possible to cover a lot of ground that appears stable. Tricky situation.
Avalanche Problem #1
Problem
New Snow
Problem #1 Comments

Based on snow pit results a deep failure of the whole snow pack is possible. I would say Moderate in terms of probability but Considerable in terms of consequences. The upper bridge could lead to a very large false sense of safety.

Avalanche Problem #2
Problem
New Snow
Problem #2 Comments

Failure plane at base of storm snow is stubborn but there. Moderate hazard based on resistance to shear and ECTN.

Snow Profile
Aspect
Northwest
Elevation
9,600'
Slope Angle
20°
Comments

Today was a good day not to take Bruce's advice to carry a rope. It would have been way too tempting to poke around in Dutch Draw!

Based on the solid bridge and observing the West Willow slide, The chance of a huge avalanche is an overriding concern in travel choices.

The supportable feel of the snow pack coupled with the lack of in your face red flags could make it be way too easy to get suckered into trouble...

2 photos of the West Willow slide. Not sure if all of the weak snow was cleaned out.

Moderate danger on the south 1/2 of the compass.

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