Cooke City

We ski toured in Sheep Creek today, north of Cooke City.  Of note, a thin (4mm) rime crust was forming due to the high humidity/ quasi rain.  Remarkably the rime crust skied very well.  

No avalanche activity observed (low vis).  No collapsing nor cracking experienced.  Light winds and mild temps.

Snowpit attached from a 9000', due south aspect, 32 deg slope.  HS 70, ECTP24 at 26.   

Another snowpit 50' away, with the same elevation and aspect, and 33 deg steep, had a similar structure, but resulted in an ECTN28 on the same layer.

We experienced several collapses and had propagation in multiple ECTs performed.  HS varies between 85-105cm. Photo from 9940

Photo: BMG

Photo: BMG

Snow surface soft with ~3" of new, mod-strong SW winds at 11am 

Reactive tests in snowpits with low to moderate ECTP scores.  HS 105, NE aspects at 9480'.  

Experienced collapsing on the north end of Rob's, likely failing on buried surface hoar that was evident in pit.  

We toured above 9000' on a W to SW aspects on Henderson Mtn.  We experienced several collapses and had propagation in multiple ECTs performed.  HS varies between 85-105cm.  Snowpilot pit is from 9820' W aspect, photo from 9940': both with ECTP results.  

Snow surface variable with wind boards and radiation crusts, mixed with soft snow in shaded aspects.  

I saw a wide slab avalanche up on west Woody Ridge from town. It happened late on Wednesday or overnight during or after the strong winds and snowfall. Photo: GNFAC

Wind slab avalanche near Lulu Pass. Photo: GNFAC

Large persistant slab avalanche on Henderson. Photo: GNFAC