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Observation Date
1/12/2013
Observer Name
Greg Gagne
Region
Salt Lake
Location Name or Route
Millcreek Canyon
Weather
Sky
Broken
Weather Comments
-18C at 9000' late morning. The Wasatch doesn't get much colder. Fortunately no wind at our elevations. Overcast skies in the morning to clearing later in the afternoon.
Snow Characteristics
New Snow Depth
2'
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments
Impressive snow totals at mid-elevations in Millcreek Canyon. In some wind-drifted areas I was finding new snow depths up to a meter (3'), although for the most part new snow depths were 60-75 cms (24-30"). HS 1.5 - 2 meters. Snow felt quite a bit stiffer today than yesterday in Butler Trees in mid-BCC. Difficult trailbreaking and you needed to push slope angles to be able to make turns.
Red Flags
Red Flags
Heavy Snowfall
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
Widespread cracking and collapsing today with two issues - (1) collapsing on the facets buried underneath the rime crust, and (2) new snow remained sensitive. I think this is more of an issue at the mid-elevations where they received the bulk of the storm snow.
Comments

Where we were traveling it was clearly a day to watch slope angles as well as anything above you and play things conservatively. Several loud collapses and cracking, with one crack propagating easily 20 meters (60') I did not see any evidence of naturals or human-triggered avalanches, but I think things were right on the brink and safe travel decisions dominated the day. I was finding more evidence of the buried rime crust in Millcreek than in Butler Fork in BCC, yet it did seem spatially variable so I really don't trust decision making based upon absence of the rime crust ..... because it may be present further down the slope or on a slope if you change aspects slightly. New snow instabilities will heal rapidly and I suspect the biggest concern at the mid elevations will be the New Years facets preserved underneath the rime crust. The faceted layer underneath the rime crust is anywhere from 60-100 cms down from the snow surface with the faceted layer 5-15 cms thick. I don't think there is a pattern to where the rime crust is present, so I'm not sure any aspect is necessarily green light once new snow instabilities settle out. I do not have a handle on this issue yet and once things settle out it will require careful and thorough stability testing.

[For my old friend who I ran into on the skin track today - great seeing you.]

FORECASTER NOTE: Greg is someone who's observations you should pay attention to. His observations are spot on. Greg, we have a position for you at the UAC if you ever are not working at Westminister! Kobernik