Quick report
- Red Flags
- Heavy Snowfall, Wind Loading, Poor Snowpack Structure
- Red Flags Comment
- <p>As I noted several days ago in White Pine, the low density surface snow on the northerly aspects concerned me because a warm, wet windy storm was about to be deposited on top of it. And today, everything on upper elevation shady slopes had an obvious, slabby feel. In several quick column tests it was shearing off on the snow surface from before this latest round of snow from light to medium taps about 30-40 cm deep. The slabs were stubborn, though, and I jumped on several wind loaded test slopes on the way up the northwest ridge and did not get any collapsing, cracking or slabs breaking out. Obviously I did not jump on any of the steeper, higher consequence slopes and gave the monster cornices a wide berth. The new snow is so dense and warm that it's probably healing up quite fast. When we skied down on the northwest graded trees, we stayed on gentler terrain because I didn't quite trust the slabby snow. I was surprised not to see any avalanches or be able to get any test slopes to respond, but from reading the other obs from today, it looks like several others found them. With the colder temperatures and lower density snow forecast for Friday-Saturday, I'm guessing that most avalanche activity will be within the new snow but I also wouldn't be surprised to see isolated slides breaking down deeper to the layer that was active recently. </p>
A couple of photos:
1) The obligatory cabin wind loading shot from Alta a couple days ago.
2) From today, heading up the ridge staying well back from the edge of cornices with high consequence slopes below.
Snowpack
New snow was quite dense--mostly graupel--like most of the storms this past month or so and it was slabby, meaning that you would punch through the dense surface snow into the lower density snow from before the storm. Below about 9,000' the snow was damp because of the high freezing levels from the past storm.