Professional Observation
Basic Information
Observation Details
Observation Date:
December 18, 2022Submitted:
December 18, 2022Observer:
Everett Phillips | ESAC ForecasterZone or Region:
McGee CreekLocation:
McGee Mountain - Snowpack ObservationsSigns of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedKey Points
Tour on McGee to evaluate the distribution and sensitivity of the Persistent Slab problem.
- On McGee low snow prior to our latest storms means the the PWL is more likely to be found on higher elevation N facing and wind protected slopes.
- The cutoff elevation where there was a significant faceted layer was above 9,000′. Lower than that the layer is thin enough to be interrupted by ground anchors (sage brush).
- Above that elevation wind scouring makes the layer intermittent and the distribution difficult to pin down.
- Overall HS ranges from 40 to 100cm. Where the PWL has good continuity it is near enough to the surface to propagate in the ECT.
After a day devoted to pinning down the PWL in the McGee area significant uncertainty remains as to how likely human triggering is, but it is possible.
Media
Advanced Information
Weather Summary
Cloud Cover:
ClearTemperature:
26 FWind:
Calm
Sunny with light winds below treeline. Calm winds on the ridge. 5 F in the parking lot (6900′) at 9 AM – brrr. 26 F on the ridge (10500′) at 2 PM. Beautiful day with incredible visibility.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Comments | Photo |
|---|---|---|---|---|---|---|---|---|---|
| 2 | Within the past week |
Lower N slopes of McGee 9100 |
D1.5 | U | Newer crowns, not as filled in. Shallower than other crowns observed since storm. Wind Slabs from Sunday 12/12 or Monday 12/13? |
|
|||
| 1 | Older than a week |
Steep North Facing Panel on McGee NE Face N 10,000' |
D2 | HS | O-Old Snow | 3 ft | N-Natural |
|