Quick report
- Red Flags
- Heavy Snowfall, Poor Snowpack Structure
- Red Flags Comment
- <p>Any time you get this amount of snow on a weak pre-existing snowpack, it is a red flag.</p>
Route today was in Beartrap. Ordinarily not likely to submit an observation from this drainage on most days, but given the amount of storm snow that fell on a weak pre-existing pack, hopefully this will be useful. (No photos or videos.)
Knowing that higher snow totals were favoring lower to mid elevations, as well as less than stellar reports from mid-BCC yesterday, was not expecting ideal conditions. But even though Beartrap trailhead had only modest snow amounts, we were finding about 45-60 cms (18-24") new storm snow above about 9000'.
Did LOTS of pole plants and hand pits down to the ground to look at buried weak layers. On north aspects above 9000' the bottom 30-45 cms (12-18") was weak faceted snow and depth hoar. However despite jumping on all sorts of slopes where this was buried, we could not get a single collapse, nor any cracking in the new snow. There are also some small test slopes in Beartrap that are great for safely evaluating snow stability, and we could only get sluffing in the top 30 cms of snow that fell overnight.
Very poor visibility, so hard to tell how things look in alpine areas, but we did look into Dutch Draw and noticed what may have been a small natural sluff due to a cornice fall, but it did not appear to step down to deeper layers. Some cornice development was going on from NW winds, so we also chose to stay well back from the ridgeline.
This is only a single data point, but I am guessing the very light density snow totaling about an inch of water weight with minimal wind (at least so far) may not have been enough for the hinges to come off of our snowpack. My hunch is there hasn't been enough of a load for a natural avalanche cycle, but that the snowpack may not tolerate triggers very well.
Mark said it well in today's forecast: we don't have any history with our snowpack so far this season and this is the first test, so it is worthwhile giving a wide berth in avalanche terrain.
Am eager to hear what others are seeing out there.
Fortunately the light density snow is very easy to move through on lower angled terrain, and the skiing today was easily the best of the year, and better than any day I remember last year. Classic Wasatch powder day.
Snowpack
- Instability Comment
- <p>Lots of buried weak layers underneath all this beautiful new load of snow.</p> <p>This super-light density new snow is great for getting sluffs moving. A few ski cuts on steep test slopes could easily get the 30 cms that fell overnight to sluff.</p>
HS on NW aspects between 9K and 10K in mid BCC are totaling about 1.0 meter (~36-40"). Storm snow is about 60 cms (2').
New snow is super, super light density.