Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2.5
Storm and wind slab formation is expected throughout the day on Wednesday. Slabs will be the largest and most reactive in wind-loaded terrain.
Dangerous avalanche conditions persist at all elevations!
The current snowpack is unusually complex and may show little or no warning signs before producing very large avalanches.
Storm and wind slab formation is expected throughout the day on Wednesday. Slabs will be the largest and most reactive in wind-loaded terrain.
Three problematic persistent weak layers exist in the upper 170 cm of the snowpack. Large, destructive avalanches are possible, even on low-angle slopes.
Large natural or rider-triggered persistent slab avalanches have been reported daily over the past week, ranging in size from 1 to 4 and occurring throughout the region at all elevations. A few have occurred in low-angle terrain that typically wouldn’t avalanche.
Although natural avalanche activity has slowed since the weekend, it remains uncertain whether the small amounts of snow and light wind expected on Wednesday will be enough to trigger new natural avalanches.
Up to 100 cm of recent storm snow continues to settle atop an unusually complex snowpack.
Three persistent weak layers of concern are found in the upper 180 cm of the snowpack:
60 to 70 cm down is a layer of surface hoar in sheltered areas, or a melt-freeze crust on sun-exposed slopes from mid-February.
90 to 120 cm down is the early-February layer of surface hoar in wind-sheltered terrain and a crust on sun-exposed slopes.
110 to 140 cm down is the late-January layer of surface hoar and facets over a melt-freeze crust.
All of these persistent layers have continued to produce large avalanches.
Below this, the remainder of the snowpack is well consolidated and strong.
Tuesday Night
Cloudy. 10 to 15 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1600 m.
Wednesday
Cloudy. 4 to 10 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -3 °C. Freezing level 1700 m.
Thursday
Mostly cloudy. 2 to 5 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -5 °C.
Friday
Mostly cloudy. 1 to 10 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.