Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Possible
- Größe
- 1.5–2.5
Unfortunately this problem is not going away and we keep getting reports of people triggering avalanches...The possibility of triggering a 2-4' thick avalanche breaking on a layer of buried surface hoar from valentines day remains possible as test scores have showed propagation into the moderate to hard range (ECTP18-24). This layer of buried surface hoar produced 2 widespread natural avalanche cycles over the past week and has been found everywhere in our advisory area. On some slopes these slabs also rest on weak combinations of crusts and surface hoar.
The most recent human triggered avalanche involving this snow occurred Thursday North of Mccall, when riders triggered a slope remotely. Triggering an avalanche involving deeper layers of facets from January is less likely than the "2-4 foot thick" fresh slabs listed above, but the consequences are far greater and the low chance of stepping down to 2/8 layers are still possible as these weak layers are persistent which means the will linger for some time with an insulator of dense snow above them.
(2/26/2026)
Thursday, riders remotely triggered this avalanche near Frog Lake north of McCall.