Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1.5–2.5
Weak layers of small persistent facets are buried 2-3 feet deep by soft slabs. Many D1-2.5 human triggered avalanches have been reported almost everyday primarily on N-NE-E-SE aspects above 7500’. Terrain where these weak layers are most reactive are being actively loaded by south/southwest wind. Any fresh formed wind or storm slabs could break on buried weak layers producing large propagation cross-slope or upslope. Wind loaded terrain will be the most dangerous today due to the consequences of not only triggering a wind slab, but also a persistent slab. Use careful route-finding to steer clear of wind loaded slopes. Keep in mind that steep, sheltered terrain also has the capability of producing larger avalanches on buried weak layers. Signs of instability such as cracking or collapsing may not be present before triggering a large avalanche.
Numerous large avalanches with significant propagation were reported yesterday in Jensen Canyon (See Recent Observations for more details).
(2/14/2025)
Persistent slab avalanche triggered yesterday showing the large propagation potential. Notice the cornice above the crown. Wind slab and persistent slab avalanches will overlap in their location today.