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Observation Date
12/29/2013
Observer Name
Bruce Tremper
Region
Salt Lake » Park City Ridgeline » Monitors
Location Name or Route
Monitors - Willows
Weather
Sky
Clear
Wind Direction
Northwest
Wind Speed
Moderate
Weather Comments
Cool to almost cold day with a moderate wind from the northwest. Much different than the very warm days we've had lately
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Snow Characteristics Comments

Extremely variable conditions, as is often the case when we have not had much snow in awhile. Icy, refrozen sun crusts on all the sun exposed slopes, wind damage along the upper elevation ridges, lots of soft, recrystalized snow on the shady aspects--northwest, north, northeast and east facing slopes. There's about 70 cm of settled snow 2 - 2.5 feet. It's rotting away from top to bottom and in areas out of the wind you sometimes sink through to the rocks or ground. Sometimes you just sandbox on the steeper terrain, mushing down to the ground.

Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
Not many red flags left. Yes, the snowpack structure is very weak but not necessarily unstable because the overlying slab is rotting away through temperature gradient metamorphism. I am getting much fewer, energetic collapses and propagations on my snowpit tests.
Avalanche Problem #1
Problem
New Snow
Problem #1 Comments

With persistent slabs they SLOWLY--sometimes over many days--become safer and safer when they go without new loading. We're at that stage where most of the overlying slabs have rotted to the point that the snowpack has lost its energy. It is starting to remind me of thumping on an over ripe watermelon--that kind of dead feeling. In most of the wind and sun sheltered slopes, there's just deep, rotten snow with little overlying slab so you most likely won't trigger a slide there. But up along the ridges where there are stiffer wind slabs on top of the house of cards, you may be able to pop something out. So it's a very tricky situation and it changes sometimes dramatically from one spot to the next. Most of the cagy, old avalanche pros still don't trust it and they continue to avoid gambling with their life. It's been days now and I still just don't like it.

What is the danger rating? Tell you the truth, we really don't know. The danger rating depends on both the likelihood of triggering a slide and the consequences of the slide. The consequences remain high because most of these slab avalanches are not only 2-3 feet deep but with such a thin snowpack you get raked over the rocks and logs. The only factor that SLOWLY changes with time is the likelihood of triggering a slide. In other words, we are stuck in that low probability - high consequence never-land. I'm thinking most slopes are Moderate danger but still Considerable above 9,500' on the shady aspects. Plus, they winds have picked up tonight and that may exacerbate the problem again.

The Moderate danger ratings I listed below are for the terrain I was in today. I am guessing that above 9,500' especially on wind loaded slopes, the danger is more like Considerable.

Comments

Sorry, even though I shot lots of video today, and dug lots of snow profiles, I did not include any graphics because the snow is so variable from place to place it just does not seem worth it to include data points with such wide variability. Plus, I just ran out of time. Gotta get up at 3:00 am to forecast.

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