Quick report
- Aspect
- North
- Red Flags
- Recent Avalanches, Wind Loading, Rapid Warming, Poor Snowpack Structure
- Elevation
- 2865 m
- Slope Angle
- 25°
- Red Flags Comment
- <p>Recent Avalacnches- Kicked one small corncie and let loose a 40' by 20' by 10" slab on a 35 degree rollover. Not enough to bury someone but definitely would have raked someone into the trees below Wind Loading- Observed loading today on north facing slopes. New cornices/ Alta Mt Baldy data from MESOWEST leads me to believe north facing slopes have recieved consistent loading the past few days. Rapid Warming- Periods of "greenhousing" defiitely warmed the top layers of the snowpack. With tmrws bit of warm clear air, I dont think this problem is going away Poor snowpack Structure- Last weeks upside down snow was reactive with clean planar shears on the density change</p>
One often overlooked and misunderstood characteristic of the snowpack is how test results are extremely temperature dependent. Biggest snowpilot complaint for me is that the temperature function displays only .5 degree increments. Many layers that appear to have no temperature gradient, did in fact have one present.
While instructing a course of the U, I dug this full depth pit to get a feel what snow depths are like in upper Big Cottonwood. Down low, the layers were extremely stout. No results below the K+ layer ~65cm up. Most alarming was the Q1 shears at 69cm. Although these took a lot of force to get, If a trigger is large enough to get this failure the results could be large and dangerous. Potential for smaller avalanches to step down to this layer as well.
Snowpack
- Instability Comment
- <p>Pockets of loaded zones were reactive today, don't see it going away with more winds tonight. </p> <p>Last weeks storm snow doesn't seem to be propagating and creating a good slab anymore. ECTs did not propagate across any columns today.</p>
New snow roughly 8-10cm with a small layer of heavily rimed precip particles below it (likely from yesterdays period of high convection). Storm snow from last week is well into decomposing/destructive metamorphism phase. I wouldn't call it "new snow" anymore.
Low cloud cover and warm temps are definitely making a damp top 20cm of snow. Still not a lot of free water in the snowpack, just high densities. Today I would divide the elevations throughout the range as those who received liquid rain and have free water in the upper snowpack and elevations above the snow line with no free water. Below the line, lack of cohesion (decreased strength) in the upper snowpack was creating lots of rollerballs and some point releases along the road.