The Valentine's Day weak layer has become reactive in stability tests after last week's snow and strong wind events. Myself and other observers have also found more recent faceted weak layers higher up in the pack. This more recent weak layer was likely buried by the 13" that fell on 2/22. The distribution of both of these layers is spotty - they are showing up in some places and not others. Both layers have produced propagation in Extended Column Tests. You can look back through old observations and previous forecasts starting on 2/14 to see the history of these layers. Here's a summary of recent findings:
- Saturday 3/4: Corkscrew Glades ECTP 21 down about 40cm on the 2/22 facets. 28 degree slope, 10,130 ft, NW (321 degrees).
- Saturday 3/4: Corkscrew Glades ECTP 26 down 57 cm on 2/14 facets. 28 degree slope. 10,188 ft, NW (307 degrees).
- Monday 3/6: While ascending the Moraines in lower Miner's Basin we dug at 8,830 ft on a 24 degree slope with a NW aspect (319 degrees). We did not find any weak layers in the pit. We continued climbing and got to a steeper slope (NW) at 9,400 ft. that was more protected from the wind and in partial shade. We could easily feel the 2/22 weak layer about 18 inches down with pole probing.
- Tuesday 3/7: Pit 1: Middle Cirque Glades 31 degree slope at 10,760 with a N (9 degrees) aspect. No weak layers. Pit 2: GB Moraines 24 degree slope 10,380 ft with a NE aspect (55 degrees). No weak layers. Pit 3: Below Exxon's 19 degree slope at 9,930 ft with a NE (60 degrees) aspect. I found a very thin, hard to detect layer of 0.5mm facets down 37 cm. This is most likely the 2/22 layer. This layer did not react to stability tests today.
A trend I am noticing is that these faceted layers seem to be at lower elevations in sheltered terrain. I think the take home right now is if you are skiing Northerly aspects dig occasional pits as you ascend and look for facets. These layers are found in the top meter of the snowpack and you can locate them pretty quickly. For what's it's worth, I skied a short, but steep (40ish degree) slope below Middle Cirque today adjacent to Pit 1 where I didn't find any weak layers.
