Avalanche: Little Pine

Observer Name
Andy Rich
Observation Date
Saturday, March 9, 2013
Avalanche Date
Saturday, March 9, 2013
Region
Salt Lake » Little Cottonwood Canyon » Little Pine
Location Name or Route
Little Pine, LCC
Elevation
9,800'
Aspect
South
Slope Angle
40°
Trigger
Skier
Trigger: additional info
Intentionally Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Wind Drifted Snow
Weak Layer
Density Change
Depth
5"
Width
40'
Vertical
400'
Comments

Several wind deposited pockets in Little Pine today that became more sensitive as the day went on. We started up the couloir ~9 and skied down it, off by 2 or so (before any clearing or direct sun). Very little deposition below 8800', more as we gained elevation. Deepest pockets of new snow ~15cm. Old snow surface very firm sun crust, below that a variety of melt freeze grains, facets and crusts. We got a few shooting cracks in the new snow as we went up, but nothing that went more than a few feet and nothing that went any deeper than the new snow. Kept looking for signs of any instability in the old snow but seemed to be limited to the new snow. At the top of the couloir, ~30 feet below the ridge we got a collapse in the new snow that propagated all the way across the couloir (~40') and despite ample steepness didn't overcome friction and cause an avalanche. As we spun and headed down we pulled a few very small pockets and had some shooting cracks from ridge height (10,700') down about 1000'. At one of the steeper pinches (~9800") I ski cut the top of a rollover that did propagate all the way across the couloir and ran several hundred feet vertical. Crown was ~15cm. All the cracking, collapsing and avalanching we saw was in fist hardness new snow wind slab with grain size and density change. Weak layer seemed to be in the new snow and a few cm of the new snow remained on the old snow surface after it slid. Not really enough snow mass to be very scary, although the firm old snow surface and steepness of the terrain did make it heads up. A nice outing, but not what I would call good skiing.

Coordinates