Sign Up for the Utah Snow and Avalanche Workshop (USAW) on December 7th!

Avalanche: Main Days

Observer Name
Grainger, Ward
Observation Date
Monday, March 7, 2022
Avalanche Date
Monday, March 7, 2022
Region
Salt Lake » Big Cottonwood Canyon » Days Fork » Main Days
Location Name or Route
Main Days
Elevation
10,100'
Aspect
Northeast
Slope Angle
38°
Trigger
Skier
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
15"
Comments
A fresh coat of paint but the same February facets problem persists in isolated areas.
At this point N through E facing slopes above ~9000' hold this faceted layer with the last 2 storms' snow on top. In multiple Days Fork subdrainages that looks 8-16" of soft snow on top of the weak interface. As the slopes get more solar-facing, last week's temperatures turned the surface into a M/F crust and the underlying facets are either not present or much less of a problem.
The reason more slab avalanches are not happening is a lack of slab cohesion. Saturday night's snow came in light density with little wind and many suspect places I dug had the weakness for failure but not the propagation propensity. Clean planar ECTN 7 and 8 (shovel-width) and PST 25/100 (Slab Fracture) all failed on the Feb facets on high NE faces. Easy failure, little connection. Wednesday snow could tip the scales in some of these areas.
In travel we had 2 localized collapses, saw 2 small D1 skier-triggered slabs (Pics 1&3) and intentionally triggered one small slab (Pic 2 crown, pole 14" down in developed facets interface).
Coordinates