Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Unlikely
- Größe
- 2
Last week sometime, a party of riders triggered this avalanche on the North Slope near the Humpy Basin. Evidence is sparse, but some strong detective work from Professional Observer Trevor Katz helped piece things together, and we speculate a catch and carry that looks to be a close call. You can find more on their report here.
Upper elevation slopes facing the north half of the compass harbor early-season snow that grew weak and sugary during the November dryspell. Last week's storms combined with strong winds buried the weak layer 1-2 feet deep, creating our main avalanche hazard, persistent slab avalanches. Suspect terrain includes shady, upper-elevation, rocky slopes where, once triggered, today's avalanches could break wider than you expect and prove to be a nasty ride.
It has been over a week since the last persistent slab avalanche was reported. As time wears on and the snowpack finds comfort in its own skin, we are seeing fewer red flags, or obvious clues of instability like cracking and collapsing. But sometimes we need to take a deeper look under the hood to understand what is going on. A quick shovel excavation reveals a strong, dense slab over weak, sugary snow. That combo creates a trap-door feeling when we're trenching our sled or ski track.