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Observation: Little Cottonwood Canyon

Observation Date
3/30/2017
Observer Name
Greg Gagne
Region
Salt Lake » Little Cottonwood Canyon
Location Name or Route
Upper LCC/BCC
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
South
Wind Speed
Light
Weather Comments
Rain/Snow line between 8500/9000' but dropped throughout the afternoon. Light southerly winds along ridgetops.
Snow Characteristics
New Snow Depth
1"
New Snow Density
High
Snow Surface Conditions
Melt-Freeze Crust
Damp
Snow Characteristics Comments

Snow surface damp up to 9500'. Above that a widespread breakable crust on most aspects with the exception of upper elevation due north.

About 2 cms (~1 new) with rain apparent up to at least 9000'. At 10,000' top 20 cms (8") of the snowpack moist, with dry snow underneath.

Comments

Low hazard this afternoon, although I wouldn't be surprised if there was some small wet, loose activity below 9000' due to rain-on-snow.

The trace-2 cms new has bonded well to old snow surface, and new snow is damp, so any snow that comes in overnight should continue to bond well. If we get the low end of forecasted amounts (3-5") some loose avalanches possible on Friday. If we exceed the high end, watch for drifting in the upper elevations and in unusual places, due to forecasted easterly winds.

Starting to think more about the north aspects as they will undergo warming as we enter April. Dug a pit at 10,000' on a NE aspect. 55 cms (22") storm snow since Wed 3/22. The snow that fell on 3/22 was a graupel layer, and it is sitting on top of a melt-freeze crust. Was able to get easy to moderate shears, at either Q1 or Q2 failing at this graupel layer. Not a concern for now, but am watching the structure of the snowpack on upper elevation (> 10000') aspects as we enter April and expect warming at the upper elevation shady aspects.

Ty Falk has a super nice observation from Tuesday where he is also noticing this graupel layer in upper elevations in Cardiff Fork.

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