Observation: Alta Periphery

Observation Date
3/24/2013
Observer Name
Greg Gagne
Region
Salt Lake
Location Name or Route
Upper LCC Perimeter
Weather
Sky
Broken
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Mostly calm conditions with some occasional light gusts of wind out of the NW. No wind loading observed. Few shaded temperature measurements I made today never got above -7C (~17F).
Snow Characteristics
New Snow Depth
2"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments

Another 5 cms overnight in upper LCC to make an already beautiful landscape somehow even more beautiful. (Excuse the embellishments.)

Comments

Toured the upper LCC periphery with my family today covering a fair amount of territory > 10000'. Predictably, snow was even less sensitive today than Saturday. No cracking and cornice kicks could only produce very minor sluffing in the snow surface which would only run short distances. Whatever wind deposited snow I could find was not sensitive (you often have to dig down to your forearm or elbow to even find wind deposits from late in the week.) Several ski cuts on steeper rollovers only produced minor sluffing at best. Settled storm totals from Wednesday range from 40-50 cms (16-20") with even some higher amounts where drifting has occurred. The only thing of interest is with quick hand pits you are still able to get moderate to hard shears at the interface of the Wed/Thursday storm snow with the Friday/Saturday storm snow. However, the slab on top is not sensitive and any fracturing at this weak layer is not leading to a propagation.

The key to stability today was the combination of continued stabilization of the storm snow plus the very cooperative weather. Temps remained rather cool, and there was just enough cloud cover to keep the solar aspects from becoming active. Light winds out of the NW also helped.

I read Drew's blog entry before submitting this obs, and my nowcast for today was a Low hazard:

  • All evidence indicates storm snow from past four days is stable.
  • Recent wind slabs were not reactive.
  • Apart from some minor dampening of the snow surface on solar aspects, very little sun and warming affecting the new snow.
  • Tracks everywhere. (Which gives me more confidence with new snow instabilities, not so much with deep slab instabilities.)

Lastly, saw lots of folks out today enjoying one of the better stretches of powder skiing in some time with all sorts of steep lines being skied. Yet, even though there was a mostly Low hazard, saw almost all parties ski one at a time and getting out of the way at the bottom. Good to see people not abandon protocol even with stable conditions.