Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Storm totals on Togwotee were 10-12” with roughly 1” of SWE. This snow has fallen on weak, sugary snow and has bonded poorly. This sugary snow has created a persistent weak layer that we are seeing widespread collapsing and cracking on. Combined with old crusts on southerly aspects that are also not bonding well, we have a widely distributed problem. Look for buried stiff slabs built by strong winds before the storm. These will be found on W-NW-N-NE aspects around ridges and exposed terrain and could be up to 3 feet thick and buried by the recent storm.
Jumping off the sled and digging a quick hand pit can identify these layers. If you're skinning, probing down with your pole is a great way to feel weak facets or stiff slabs below the recent storm snow. As you travel, watch for shooting cracks and whumpfing, sure signs of an unstable snowpack. Avoid steep rocky terrain and areas where the snowpack is thin and more easily triggered. As you approach large, connected slopes, remember that these avalanches can be triggered remotely or from below. Watch out for terrain traps (small, tight gullies, creek beds or other corridors below connected slopes) where even small avalanches can very quickly bury you.
(12/4/2023)
Widespread Shooting Cracks on Angle Mountain (Togwotee)
Photo: Travis Baldwin