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Observation: City Creek Peak

Observation Date
2/18/2019
Observer Name
Bombard, Pioli
Region
Southwest » Tushers » City Creek Peak
Location Name or Route
Tushars/City Creek Peak
Red Flags
Red Flags
Heavy Snowfall
Wind Loading
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
A foot of basal facets are buried beneath 5' (160cm) of solid slab in the area of City Creek Peak. They're so deep down in the HS185cm pack, and the slab on top of them is so thick and stable, they're unlikely to react to all but the heaviest triggers -- a big honkin' cornice? a sled on the just right soft spot? In the off chance that does give though, the snow would break to ground and the results would be catastrophic.
It's an entirely different story in the mid elevations, where the snowpack is precariously thin (HS100) and the basal facets are dangerously reactive. CTP13 on that basal facet layer. Didn't do an ECT, but suspect propagation on that collapsing layer. Although the snow keeps falling in the Southwest region -- we enjoyed nearly constant snow storms for three straight days, with more predicted this week -- it won't be enough soon enough to insulate the mid elevations from the consequences of that buried instabilty.
Calling this a considerable problem in the mid-elevations, especially on steep northeast through northwest slopes; moderate in the upper elevations at all aspects.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
Cross-loading and some moderate to strong wind transported snow in the most exposed upper elevations -- Mount Holly, Lake Peak, City Creek Peak. There wasn't much sign of wind disturbance across the Tushars, where most of the trees are still decorated with thick piles of white.
Grading this a moderate problem in the upper elevations above treeline on southern aspects.
Comments
All in all, conditions are pretty stable.
Good skiing in deep, dry powder below the wind-scoured alpine terrain.
We found more snow in better shape than we expected to -- at the upper elevations, that is. Up there, we might even go so far as to advise general caution, especially given the remoteness of much of Utah's southwestern ranges. The mid-elevations are concerning, but the skiing there is also really top-notch.
The new storm snow (12" since Friday evening) hasn't entirely bonded to the most recent melt-freeze layer, but it also didn't exhibit any concerning instability.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate