Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible - Likely
- Size
- 1.5–2.5
Wind slabs have formed from recent snow and strong southerly wind. Expect to find them in steep, lee terrain features near ridges.
Freezing level rising and temperature warming will increase the avalanche danger thoughout the day. Large cornices may become weak and easy to trigger.
Wind slabs have formed from recent snow and strong southerly wind. Expect to find them in steep, lee terrain features near ridges.
With rising freezing level and temperature warming during the day, large cornices developed with recent snow and wind may become weak and easy to trigger. Also, keep in mind that cornice failure may trigger large avalanches.
The freezing levels will rise significantly to over 2000 metres on Sunday but with no precipitation forecast.
SATURDAY NIGHT: Cloudy with flurries, accumulation 5 to 10 cm, 40-50 km/h southwest wind, treeline temperature -2 C with freezing level rising to 900 m.
SUNDAY: A mix of sun and cloud, no precipitation, 50-70 km/h south wind, treeline temperature 0 C with freezing level rising to 2400 m.
MONDAY: Cloudy with snow and rain, accumulation 10 to 20 cm above 1500 m and rain below, 70-90 km/h southwest wind, treeline temperature +2 C.
TUESDAY: Cloudy with snow and rain, accumulation 35 to 60 cm above 1500 m and rain below, 60-80 km/h southwest wind, treeline temperature +3 C.
Several wind slab avalanches were triggered naturally, by riders, and explosives in the last few days. They were generally 30 to 40 cm deep, on north aspects, and at treeline elevations. These slabs may still be triggerable naturally or by riders on Sunday. Below 1200 m, small pinwheels were observed out of steep terrain from Thursday night's rain.
We'd appreciate any observations while you are out travelling on the Mountain Information Network.
Wind slabs may still be found in steep, lee terrain features, which formed from recent 40 to 60 cm of snow and strong southeast to southwest wind. The snow surface below about 1200 m consists of a hard melt-freeze crust from recent rain. This overlies 100+ cm of snow that accumulated since January 1, which reports suggest is bonding well to the snowpack.
The middle and base of the snowpack are strong, consisting of well-bonded snow and various hard melt-freeze crusts.