Public Observation #2023-1105
Submitted:March 25, 2023 10:09 PM
Observation Date:March 25, 2023
Zone or Region:Central Cascades
Did you trigger any avalanches?Yes
Was it intentional?No
Avalanche Type:Hard Slab
Size:D1: Relatively harmless to people
Comments:25-30cm. 20m wide. 30m long. Started on a convexity. Most of the snow on similar slopes was completely unconsolited storm snow. This slightly more open area must’ve been more wind affected and caused the new snow to setup as a slab.
Signs of Unstable Snow
Did you see shooting cracks?Yes
Did you experience collapsing or whumpfing?No
ObservationsThe new snow was very deep and very unconsolidated in hand pits. However, while touring in Black Crater, we triggered a decent sized slab, that fortunately only ran about half the length of the remaining slope. The start zone was an open convexity below a small cliff and before entering into old growth trees. We didn’t measure the slope, but my guess was at or just over 35 degrees. I was about 3 turns in when my partner yelled avalanche repeatedly and then a point positive direction. The slab was broken up as it hit trees, and then entrained unconsolidated snow slid another 40m past them.
Every other similar slope that we tested was unreactive and we were fairly confident in the snow pack. One slight change in terrain and trees was all it took. The area was more open to wind, with less trees. We could’ve taken more time to reevaluate this deviation, but we didn’t, and got lucky.