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Observation: Willows

Observation Date
3/24/2018
Observer Name
Evelyn
Region
Salt Lake » Big Cottonwood Canyon » Willows
Location Name or Route
Willow Knob ridge to Park City ridgeline
Weather
Sky
Scattered
Wind Direction
South
Wind Speed
Light
Weather Comments
Increasing clouds through out the tour. Winds gusty along exposed ridgelines, but finding very little snow to transport.
Snow Characteristics
Snow Surface Conditions
Dense Loose
Faceted Loose
Melt-Freeze Crust
Damp
Snow Characteristics Comments

Spring conditions, with an excellent overnight refreeze. Was surprised to find a rock hard, supportable snow surface a 7,400' with a late-ish start. While it later nicely softened, it was still fully supportable at the lower elevations. All aspects and elevations I traveled were supportable, and slow to soften today due to clouds and wind. West facing slopes were the iciest, and probably never softened due to the incoming clouds. It was basically a spring corn day, with some softening on sunny aspects and a shallow layer of soft powder/graupel on mid and upper elevation northerly.

Snow on northerly facing slopes seemed loose and slightly faceted.

Could have used ski crampons, so ended up booting one section. With cooling temperatures for the next 3 days, expect widespread hard snow surfaces, and ski crampons, whippets, ice axes and crampons may be important depending on your project.

Red Flags
Red Flags
Recent Avalanches
Wind Loading
Poor Snowpack Structure
Red Flags Comments
The large avalanche in Two Dog, upper Days Fork, could be seen. No other similar avalanches seen, though resorts have gotten similar slides with avalanche reduction work. Wind loading was minor where I was, but could be more significant at higher elevations.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments

My greatest concern would be upper elevation north through easterly, shallow snow pack areas, and those that are steep and rocky, heavily wind loaded or have slide one or more times this year. The faceted weak layers are more deeply buried, but still a concern in isolated places.

Avalanche Problem #2
Problem
Wet Snow
Trend
Decreasing Danger
Problem #2 Comments

Seems like it's over for now. I'm surprised, but a single overnight refreeze, and the wet snow froze into a 2 to 5" thick very hard ice crust. Very supportable, and very strong. Some moist to possibly wet snow layers deeper in the snowpack, but I would think those layers would be very hard to trigger now. And with another 3 days of cold, below freezing temperatures in the forecast, any moist layers will continue to cool and strengthen.

Snow Profile
Aspect
Northwest
Elevation
9,400'
Comments

I had to use a snow saw to get through the upper layer ice layer. General feeling of a cooling and strengthening snow pack between this pit and other quick pits.

Below - the supportable ice layer, 9400'.

1st photo: westerly facing slope, scoured to icy rain crust

2nd photo: ice on tree, 9800', indicative of the high rain/snow line Thursday into Friday am.

3rd photo: super smooth surfaces - it will be really nice to have the smooth surface under our next shot of snow.

Great cloud day.

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