Observation: Public

Name:

Manning-Hough-Snee

Observation Date:

January 5, 2021

Submitted:

January 5, 2021

Zone or Region:

East Central

Activity:

Skiing/Snowboarding

Location:

Tronsenhead

Did you observe any avalanches?

Yes

Avalanche Type:

Soft Slab

Size:

Size 3: Could bury and destroy a car, damage a truck, destroy a wood frame house, or break a few trees

Elevation:

5800'

Aspect:

N

Comments:

The northerly cornice on Tronsenhead broke sometime in the last 24-hours above a 40-degree slope, triggering a sympathetic release that broke widely across the slope. Initially we thought it was a wind slab, but given that it ran 300' wide and long, it's more likely to have failed on the 12/21 crust, and possibly facets below. A few mature trees transported to mid-slope in the debris. SS-N-R3-D3.

Photo:

Did you see shooting cracks?

No

Did you experience collapsing or whumpfing?

Yes, Isolated

HS 50cm-90cm. Bottom ~20cm were large facets. Collapses locally to 30' in flat terrain above 5600' on poor structure. Small wind slabs noted on steep slopes at elevations above 4800' (SS-N-R1-D1). We observed a large wind slab on Windy Knob, N, 5800' that ran 200' in a gully below the corniced ridge (SS-N-R2-D2). 12/21 notable in snowpack when poling, with distinct punch below to facets. Quick pre-work outing, so didn't dig formally.