| Recent Avalanches? | No |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | No |
Observation: Summit
Location: North Gilpatrick
Toured up through most of the trees and alders to 2660′ on the E-SE face. Dug a pit and enjoyed the sun for a while. Skied back to the east and eventually found our way out of the alders back to the track.
Obvious signs of instability
Observer Comments
None observed at or above treeline. I did experience a large whumph in a protected meadow that was well below treeline. I speculate that this was from a layer of buried surface hoar that was preserved to a greater extent down low in the trees out of the wind.
Weather
Sky: Clear, with occasional low, thin clouds from the north at ~1500'.
Wind: Light from the north.
Temperature: ~ +2C.
Precipitation: None.
Snow surface
Settled powder with sun crust developing on the steeper southerly aspects (see attached photo).
Snowpack
We dug a pit to the ground at 2660', expecting to find a similar snow structure to that recently observed on Fresno and Tenderfoot ridges (buried surface hoar and melt-freeze crusts with faceting beneath). We found those weak layers, plus some well developed basal facets (see attached pit profile). We did not see propagation or clean collapsing in these weak layers during our instability tests. The best description is 'progressive compression' of the facets on the ground and under the melt-freeze crust.
While cleaning up and filling in our pit, we found that the snow depth in the immediate vicinity was more variable than we had thought, and there was a mix of grass, moss and rock surface. The data reported here could very well be a poor representation of the area.
Sun crust on new snow.
Pit profile. 02.19.2018