Observation: Public
Observation Details
Name:
Hough-Snee/SwainObservation Date:
January 1, 2021Submitted:
January 1, 2021Zone or Region:
Stevens PassActivity:
Skiing/SnowboardingLocation:
Jim HillTriggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
NoAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
4400'Aspect:
WComments:
Soft slab 28" deep to 12/21 crust. Localized feature, short running with crown to < 6 meters wide. SS-ASu-R1-D1, but might end your ski season/ACL given the weight of wet new snow.Photo:
Observed Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
5500', 5600', 6000',Aspect:
EComments:
The ridgeline between Henry's and Lanham ran naturally in many places during the storm (late 12/31 estimated). Avalanches originated at density changes and stepped down to the 12/21 crust in some cases. Ran on steep and rocky slopes slopes >40 degrees in some cases and cornice failures above 40+ degree slopes. Both released sympathetic patches in adjacent 32-38-degree terrain creating impressive crown networks.A small point release dropped into the bowl on NE proper near 6000' and caused a soft slab with a crown 40-50 meters wide. It ran far (70-meters) and relatively wide in the recent storm snow before the slope mellowed. Start zone was 38-degrees and slope it ran through was +/-34 degrees. Crowns around 40-50cm deep.
These are the same layers that NWAC forecasters identified in the field today (1/1/21) in the adjacent Lanham lake area.
Photo:
Signs of Unstable Snow
Did you see shooting cracks?
NoDid you experience collapsing or whumpfing?
Yes, IsolatedObservations
HS is getting to be more than a 325 cm probe on windy ridges as low as 5500'. Storm slabs had enough new storm snow to entrain that they stepped down to 12/21 crust. At one crown, it appeared the slab broke 8-10cm above the 12/21 rain crust on an unknown weak layer before stepping down to the 12/21 rain crust. No evidence of persistent slab activity below the 12/21 crust. Remaining snowpack will be tested by incoming 2" of water anticipated 1/1-1/2.
Media
