Sat, Mar 6, 2021 - 4:57 PM
Three Sisters Area / 7790'
Snow Conditions No Avalanche Activity
Broken (5/8 - 7/8)
Graupel and Hail / S1 Light snow
Height of Snow (HS):
W / Moderate: 17-25 mph
Ball butte has a pretty widespread rain crust, supportable to skis, but boots will go through it. I dug a pit on the SE ridge at 7790', the crust was 6-10cm thick. The crust appears to be well bonded to the snowpack below. On top of that crust last night we received about 2-5cm of new snow. This can be deeper, up to 15cm, in the gut of the bowls and gives good skiing, with only the occasional scrape.
Where I dug, below the ridge, the new snow was fist hardness and appeared very low density. On top of this new wind transported snow was forming a thin denser layer. While not a hazard at this stage, it is interesting to note the mechanism of formation of wind slabs. See Pic.
At 7790' on Ball Butte at 10:45am winds where light to moderate from the west. Visibility was good with broken cumulus clouds. Air temp was -7c (20f). I saw light blowing snow from the ridges. While ski cutting I saw no cracking or sighs of instability. I saw no signs of previous avalanches.
At 11:42 we had a 20min period of small grauple to add to the surface of the snowpack. See pic.