Professional Observation
Basic Information
Observation Details
Observation Date:
December 4, 2022Submitted:
December 5, 2022Observer:
Everett Phillips | ESAC ForecasterZone or Region:
Convict CreekLocation:
Aggie McGee Col - Blowing Snow and Widespread CollapsesSigns of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
WidespreadCollapsing was widespread, but a large clearing on a N slope at 10400′ produced an exceptional whumpf when we stepped out of our skis to dig a snowpit.
Key Points
The goal of today’s tour was to get a feel for the snowpack post-storm outside the Mammoth Lakes Basin. Takeaways:
- Poor structure and signs of instability that have been seen in other areas are present in the Tobacco Flat area where there is enough snow to cover anchors.
- ATL start zones were loading throughout the day with SW Winds, intense blowing snow, and light snowfall.
- No crown lines observed despite a good view of start zones on a variety of aspects and elevations. Evidence of avalanche activity may have been covered by wind loading over the last 12 hours.
Media
Advanced Information
Weather Summary
Cloud Cover:
Mostly CloudyTemperature:
16 FWind:
Strong , SW
Skies clearing throughout the day. Scattered snow showers. Strong SW winds and intense blowing snow ATL. Cold.
Snowpack Observations
HS: 0-130
Wind-packed snow over facets.
Good ski quality in wind sheltered pockets above 9700′
Below 9700′ breakable wind crust and thin coverage require creative route finding.