24-25

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

Persistant slab avalanche on Fisher that broke near the ground. Photo: GNFAC

We rode out to Lulu Pass to look at the few avalanches that were reported yesterday on Henderson and Fisher Mtn. Today we did not see any avalanches that weren't previously reported, other than one small, but thick wind slab on south facing slope of Scotch Bonnet (photo). At least the avalanche on Fisher and one on Henderson broke near the ground (pics attached). Some slides were heavily refilled by drifted snow, so it was hard to tell how deep they broke.

Yesterday I saw a wide slab avalanche up on west Woody Ridge from town (photo attached). It happened late on Wednesday or overnight during or after the strong winds and snowfall.

We dug a pit on a north-northeast facing slope below Fisher Mtn. (on Rob's Knob). Snowpack was just over 3 feet deep with a stripe of surface hoar in the middle. Generally 1F to Pencil hard slab above the SH. Facets near the ground were 2-3mm and rounding. We had ECTP22 on the surface hoar and ECTN22 and PST 25/100arr.

Despite the generally hard and rounded facets near the ground, recent avalanches are a sign that those are a problem in addition to the surface hoar.

Clear and mostly calm today. A few rollerballs on southwest aspects.

Overall, the recent avalanche activity is a sign that the early season weak layers are a problem to watch going forward. Danger and likelihood of avalanches may decrease in the immediate future with a break from loading, but we need to be thinking about these layers when future storms add up.

Dug a pit at 7600 ft on a NE facing slope. Full propagation on isolation of the column on the layer of concern about 16 inches down in this zone. Photo: Anonymous

Went out to have a look in the northern Bridgers today, hopeful that the moderate rating for the Bridgers today would lead to some fun lowish angle action. 
Dug a pit at 7600 ft on a NE facing slope. Full propagation on isolation of the column on the layer of concern about 16 inches down in this zone. Went a little higher up and got a big whumpf and that was all I needed to bail on even the lower slopes. 
 

Light winds and a sunny morning were quickly having an effect on the snowpack at history rock. Around 40f temps all day, with a moist, gloppy, snow surface. A quick dig in the top meadow showed the storm/windblown snow was moist down to the crust formed during our last high pressure, and the basal facets were also moist up to around 30cm from the ground. We saw no signs of instability in the less skied areas of the top meadow, including those that had been recently wind loaded.