Observation: Maybird Chute 1/28/2012

Observer Name:

Cawley

Region:

Salt Lake
Little Cottonwood Canyon
Maybird Chute

Observation Date:

01/28/2012

Location or Route:

Maybird Couloir, SW Face O'Sullivan Peak, out Maybird Couloir

Weather

Sky:

Clear

Wind Direction:

Northwest

Wind Speed:

Calm

Weather Comments:

Ridge-top NW winds were gusting into the moderate range, increasing in frequency by late in the day and creating small but sensitive soft and hard wind slabs. Otherwise, a calm day, with high clouds moderating the sun's influence through noon-time. ESE-S-W slopes have been damaged by the sun.

Snow Characteristics

Snow Surface Conditions:

Powder

Wind Crust

Melt-Freeze Crust

Primary Concern

Primary Concern:

Wet Avalanches

Probability:

Moderate

Aspect:

Southeast

South

Southwest

Elevation:

Mid

Low

Trend:

More Dangerous

Primary Concern Comments:

S-SW-W facing terrain is getting pretty strong sun these days, and has felt ripe for push-alanches by early afternoon when winds are calm. With a warmer day on tap for tomorrow Id expect wet snow avalanches to be easier to trigger on the right terrain feature, and that these will most certainly step down into old snow where it is present.

Secondary Concern

Secondary Concern:

Persistent Slabs

Probability:

Considerable

Aspect:

North

Northeast

East

West

Northwest

Elevation:

High

Mid

Trend:

Less Dangerous

Secondary Concern Comments:

Though we avoided travel on slopes likely to feature persistent weakness today, the views of W-N-E facing slopes in Broads Fork and across hwy 210 in lower LCC was eerie, with last weekend's massive crown-lines and full-track debris piles becoming nearly concealed by recent snow and wind. Today provided unfortunate evidence that large, human triggered avalanches are still likely in many places, though I suspect they'll get a little trickier to tickle as the days pass.

snow_profile_location:

Comments - Photos - Videos (group 1)

Seeking south facing terrain with evidence of obvious recent activity, Fabby and I ascended from highway 210 on supportable, melt-freeze crust, shaped by debris from recent activity but smoothed over by our graupel+stellars from thursday, 1/26. Climbing into the narrows of the chute below the upper face, we found occasional drifts of graupel and a long section of cold, settled powder, but otherwise the entire ascent through the upper, south-facing chute and along the south shoulder of O'Sullivan to the summit was on nearly supportable melt-freeze crust and obvious avalanche debris. We had our hands in the snow extensively and were pleased to find a consistent depth of 30-50 inches, composed entirely of last weeks' storm snow and sitting in a 1F slab above bare ground or, in a few locations, a few inches of coarse melt-freeze grains. Poking onto the S-SW face of O-Sullivan revealed very similar, if thinner and even more homogenous snow, although the surface snow was not uniformly sun-crusted and featured actual powder skiing in some places on our descent into the Lisa Falls drainage. Dropping back into Maybird on S facing at 11 AM yielded slightly softened breakable crust and actual corn snow in the lower gully.

Comments - Photos - Videos (group 2)

Following the news of today's incident on Kessler Peak, I had reservations about posting observations from more complex terrain, as I don't think anyone needs encouragement to go further afield in these conditions. I want to emphasize that our decision to go into this terrain was based on dilligent, daily observation of the south-facing slopes in LCC all season, and an impression of how avalanche activity and snowpack development had transpired in this area in recent weeks, which was confirmed by our observations as we made our initial ascent.

Forecaster Comments - Thanks for posting the observation. You've clearly done your homework in choosing the terrain and snowpack for the day. Hardesty

Observed Danger Rating:

Considerable

Forecast Danger Rating:

Considerable