Wind Slabs
- Alta montaña
- Límite del bosque
- Bajo el límite del bosque
- Probabilidad
- Likely
- Tamaño
- 1–2
New snow on Thursday will likely form wind slabs along ridgelines.
The snowpack is untrustworthy after going through dramatic weather fluctuations. Conservative low-angle routes are recommended.
New snow on Thursday will likely form wind slabs along ridgelines.
Cornices may fail and trigger slabs on the slopes below.
Persistent weak layers in the snowpack have the potential to produce very large avalanches. We have limited information about the problem in this region, but enough to recommend choosing low-angle terrain at this time.
Large storm and persistent slab avalanches (size 2 to 3) were reported on Monday on Tuesday, along with some large cornice failures. Most activity was on north-facing slopes. Wet loose avalanches were also observed on Tuesday and likely continued during the warm weather on Wednesday.
Up to 15 cm of new snow may accumulate by Thursday afternoon. Recent warming and rain have likely soaked the upper snowpack at treeline elevations, while some dry snow may exist on shaded alpine slopes.
There is a significant concern that small avalanches willl step down to deeper persistent weak layers. These consist of surface hoar, facets, or a crust:
The early March layer down 50 to 100 cm. This is the primary weak layer of concern.
Mid-Feb & Late-Jan layers down 80 to 180 cm. These layers could be triggered with heavy loads like a cornice fall or a smaller avalanche in motion.
Wednesday Night
Cloudy with 1 to 5 cm of snow above 1600 m. 20 km/h southeast ridgetop wind. Treeline temperature 0 °C. Freezing level 2000 m.
Thursday
Cloudy with 10 to 15 cm of snow. 30 km/h east ridgetop wind. Treeline temperature -3 °C. Freezing level drops from 2000 m to 1000 m.
Friday
Mostly cloudy with 5 cm of snow. 10 km/h south ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.
Saturday
Cloudy with 10 to 20 cm of snow. 20 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.
More details can be found in the Mountain Weather Forecast.