Avalanche

Granite and Grass Mtn Lakes

George HalcomSalmon River Mountains
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Quick report

Stubborn persistent slab avalanche, difficult to trigger, but could still propagate.

Small, natural wind, slab, avalanches, failing naturally and building thick areas that were not failing so it's likely that you could trigger a small to medium sized wind slab avalanche near ridge lines and cornices.

The sun was nice, but it really started making the surface mushy on aspects that were tilted towards it... later in the afternoon we did observe, pinwheels and roller balls all small D1 wet loose.

We observed recent wind slab avalanches on the north side of Granite Mountain, as well as just across the road to the East on some other north Northwest terrain. At Grass Mtn Lake West, we observed a small snowmobile triggered, persistent slab avalanche that did not run far only about 50 feet. The sun heated the snow surface enough that it was mushy, and we started to see roller balls and pinwheels form on the surface Sunday afternoon...Riding got more difficult in the heavier snow in the sun.

Weather

Cloud Cover
clear
Wind Loading
moderate
Recent Snowfall
59
Snow Avail For Transport
small smounts

Winds out of the south and cool clear skies with moderate south winds eventually warm in the afternoon noticeably.

Snowpack

Saturday and Sunday, many D2 natural wind slab avalanches were observed on east through northwest aspects widespread throughout the area that we covered from Gordon Titus to Fisher Creek to Hard Creek...test pits showed 2/15 layer of   buried surface hoar about 59 cm below the surface,  stubborn yet still has the ability to propagate: extended column tests were fully propagating after about 25 taps on the shovel. ECTP 25, CTHSC.

The surface hoar that is buried is laid down, which which has likely given it a little bit of strength pushing scores into the hard range.

Avalanche

Size
D1
Type
SS
Count
2
Aspect
SE
Trigger
AM
Elevation
7500 ft

Natural Wind slab avalanches on North aspects from recent loading which was observed, and one small snowmobile triggered avalanche from the day before.