Avalanche on Mono Jim NE Face

AVALANCHE OBSERVATION
Mono Jim

Drainage:

Submission Info
Geoff Unger
Member
Saturday, December 28, 2019 - 3:15pm
Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Avalanche Type: 
Dry
Slab
Slope: 
45degrees
Trigger type: 
Skier
Crown Height: 
Less than 1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
20ft.
Terrain: 
Near Treeline
Elevation: 
10 500ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
1 200ft.
Number of partial burials: 
0
Number of full burials: 
0
More detailed information about the avalanche: 

Today we toured up Old Man Bowl and crossed over the shoulder of Mono Jim.  Throughout the tour we were taking measurements of snow depth and the depth of the storm snow.  On the SE facing aspect of Old Man Bowl the HS was 45cm and the HST was 10cm.  On the NE Face of Mono Jim the HS was 65cm and the HST was 20cm.

The avalanche started on a narrower section of the slope where the terrain steepened slightly.  The skier cut through the crown and stood on the bed surface letting the soft slab run past and down almost to the bench below.  Given most of the entrained snow was below the skier it was relatively harmless, but you wouldn't have wanted to be in the path of this slide anywhere along the path if it was triggered from above.  A good reminder not to expose multiple skiers to the slope at once!

Avalanche observation video: 
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Below Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming
Accumulation rate: 
None
More detailed information about the weather: 

Relatively calm conditions today.  The forecast northerly winds did not impact the area where we were touring.  We saw some active wind transport on the summit of Morrisson this morning, but it seemed to slack off by noon or so.  No active loading was observed in Old Man Bowl or Mono Jim during our tour today.

Number of People Caught: 
0
NE Face Mono Jim 37° 34' 21.4968" N, 118° 51' 4.1436" W
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