Observation: Public
Observation Details
Name:
TrippObservation Date:
March 11, 2023Submitted:
March 12, 2023Zone or Region:
Snoqualmie PassActivity:
Skiing/SnowboardingLocation:
"Vortex" aka "Circus" couloir, Snoqualmie Mtn.Triggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
NoAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
5000'Aspect:
NWComments:
Wind slab at D2, R3, crown ~6" deep, propagated ~100' in length on 38ish° slope at bottom edge of rock band, ran ~1000' entraining dry snow, deposit ~2' deep and 50' wide, several hundred feet long.Signs of Unstable Snow
Did you see shooting cracks?
Yes, IsolatedDid you experience collapsing or whumpfing?
NoObservations
Nearing the top of a NW aspect couloir at 5000' we had been feeling a soft, non-cohesive slab structure around 5" deep on a 40ish° slope with obvious signs of wind effect. We had only seen isolated shooting cracks of a few feet at the corners of our skintrack turns. We felt it was safe to cautiously continue upwards booting rather than skinning, as the slab did not seem likely to cohere and release all at once. The first skier down tested for cracking on a lower-angle slope near the top, observed none, then ski cut the rollover before the start zone with no results. The first turn made onto the steeper slop triggered the D2 slab. We had ensured all nearby parties were in safe areas and the triggering skier was not caught. No burials or injuries.