Wind slabs may be found behind terrain breaks such as ridges and ribs. It may be possible for a wind slab to step down to deeper instabilities.
Persistent Slabs
N
NE
E
SE
S
SW
W
NW
Alpine
Treeline
Below treeline
Likelihood
Possible
Size
1–5
Persistent weaknesses are buried at a prime depth for human triggering. Triggering persistent slabs is most likely on south-facing slopes and in sheltered terrain below treeline.
Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
Thursday: Moderate to strong W winds. Alpine temperature near -2. Trace of snow.Friday: Light to moderate NW winds. Alpine temperature near -11. No snow.Saturday: Light SW winds. Alpine temperature near -3. No snow.
Avalanche Summary
Several naturally-triggered size 1 wind slabs were observed on Tuesday. A skier also triggered a size 1.5 slab on a north aspect at 1300 m, which failed on buried surface hoar.
Snowpack Summary
Strong north to north-westerly winds have left wind slabs in many areas, even at treeline. Settled storm snow sits above surface hoar (found especially at and below treeline in sheltered areas), a sun crust (on steep S to SW -facing slopes) and facets. The distribution of these weaknesses is patchy, but where they exist, it may still be possible to trigger a large avalanche with the weight of a person or snowmobile. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.