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Observation: Weber Canyon

Observation Date
1/21/2013
Observer Name
Bruce Tremper
Region
Uintas
Location Name or Route
Area 51
Weather
Sky
Clear
Wind Direction
West
Wind Speed
Light
Weather Comments
I went out on my day off skiing with friends. Stunning weather with clear skies and warm temperatures.
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments
There were the usual snow conditions you would find after a couple weeks of no snow and clear skies. Sun crusts on all the sun exposed slopes, hard wind crusts along the ridges and 2-2.5' of nearly bottomless faceted snow on all the shady aspects with surface hoar on top. The near-surface faceted snow rides fast and fun.
Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
The only red flag is poor snow structure but there is presently no slab on top of it, so it's a future concern, not a present concern. If it ever snows or blows, all the shady slopes will come unglued.
Avalanche Problem #1
Problem
New Snow
Trend
Decreasing Danger
Problem #1 Comments

The steep temperature gradients caused by two weeks of clear skies has rotted the entire snowpack on the shady slopes (northwest, north, northeast and east facing slopes). There are very few layers left in the snowpack because the faceting process is chewing them up. In some of the shallower spots, you easily sink through to the ground in faceted snow but most places have enough buried layers that are strong enough to hold you up but they are actively rotting away. What a mess. It's not a hazard now because there is no slab on top but if the wind blows or it snows or both, there is going to be lots of trouble.

Most of the shady slopes have lots of tracks on them. People have jumped into many slopes that are prime avalanche terrain with zero tolerance for error (with trees and terrain traps below that would be close to zero chance for survival). No one is triggering avalanches and the snowpack is quite stable in that area, so this is the time to enjoy those slopes.

Avalanche Problem #2
Problem
Persistent Weak Layer
Problem #2 Comments

There are old, hard wind slabs on many of the wind-exposed slopes but they seem dormant and unreactive. Even though they have faceted snow beneath them, It's been too many days since they were deposited and they lack any energy to crack or slide, at least the ones we crossed today. I'm always a bit suspicious about lingering, hard, wind slabs so I habitually avoid them on steep slopes anyway, but for now, these dragons seem content to snooze.

There are deep layers of surface hoar (sparkly frost) and deep layers of near-surface faceted snow on all the low elevation terrain especially around streams, so these areas will be especially dangerous if the wind creates a slab on top of them or with the next storm.

Comments

I did not record a snow profile because it would only show faceted snow top to bottom with one or two, subtle stronger layers buried about a foot deep. Plus the snow varies dramatically from place to place to graphing a snow profile is quite misleading in this kind of snow with so much "spatial variability.", which is typical in these times of extended periods without any weather.