Sensitive Wind slabs in the Mammoth Lakes basin

Red Cone
Submission Info
Monday, March 23, 2020 - 1:30pm
Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Snowpit Observations
More detailed information about the snowpack: 

I went for a tour to the Red Cone area today to assess surface instabilities and to get an idea of how the new snow has been settling. Mostly cloudy skies and intermittent snow showers this morning were broken by periods of blue skies. We measured approximately 4” of new snow from the last 24 hrs.  Winds were generally light while below treeline with ridgetop winds in the moderate to strong realm. We witnessed blowing snow throughout our tour and fresh drifting was evident at all elevations. 

Looking around the Red Cone bowl, areas of recent wind deposits were made evident by fresh cornice growth, smooth fat looking slopes and freshly covered tracks. West winds were actively moving snow and loading leeward slopes on easterly aspects. I was able to kick a small chunk of recent cornice loose which resulted in a D1 Wind slab avalanche. About 40’ wide and running approximately 500’ this shallow (6”) wind slab entrained quite a bit of loose snow and we measured the debris pile to be about 4’ deep. 

Temperatures felt warm today and humidity felt high. (1330, @10,300’, 28°F, BRK skies, mod W wind). As a result, surface snow saw a lot of settlement as we were out in the field. Ski penetration was only about 20 cm as we made our way back to the car and the snow had a slightly upside-down, sticky feel to it.  Ski cuts on steep convex rolls produced small loose dry activity below treeline today. I believe the dense surface snow made these areas more reactive then they may have been yesterday. 

Natural Loose-dry activity was apparent in very steep cliffy terrain both below and near treeline however this all looked to have occurred prior to last night's storm. We also observed a couple of small fans of rollerball activity below the Hollywood cliffs during one extended window of blue sky.


Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
-- placeholder --

ESAC receives significant financial support from ...