Observation: Public

Observation Details

Observed Avalanches

Signs of Unstable Snow

Observations

We had a few reactive pit tests on various facet/crust layers today on an East Slope at 5600' in the east central Cascade zone:

1) ECTP11 on 1mm near surface facets 35cm down and 10cm below the 12/21 crust (12/18?).
2) ECTP13 on now rounding 1mm+ facets above the 12/9 crust.
3) The same facet layer above the 12/9 crust went PST 40 End and rolled out with high energy.

Both of these tests involved isolated columns where the 12/21 crust was cut. We experienced very limited under foot collapsing and saw no cracking, which leads us to believe that there is reasonable bridging across the 2-3 cm solstice rain crust.

The takeaway here: if you somehow manage to break the thick rain crust that is bridging the pre-solstice and post-solstice snowpack, these persistent weak layers (12/9 and 12/18 facets) are still reactive and may result in relatively deep (12/9 facets) persistent slab avalanches on some terrain features.

Wx notes: nearby wind station reported W-WSW winds all day, but moderate mid-slope east and northeast winds occurred mid-day. -2C at 5600' at noon.
Pit notes: Temperature gradient from air (-2C) to 40cm into pit (-5C).