Wind Slabs
- Alpin
- Limite forestière
- Sous la limite forestière
- Probabilité
- Likely
- Taille
- 1–2
Intense wind from the southwest has left touchy slabs in leeward terrain. In some isolated sheltered areas recent snow may be settling above surface hoar.
Navigate around wind loaded slopes and keep in mind the potential for surprisingly large avalanches due to isolated weak layers.
Intense wind from the southwest has left touchy slabs in leeward terrain. In some isolated sheltered areas recent snow may be settling above surface hoar.
Triggering large avalanches on weaknesses in the lower snowpack remains a possibility. In some areas the concern is weak snow around crusts 60 to 90 cm deep, while in others it is weak snow near the bottom of the snowpack. This problem is best managed by avoiding steep rocky slopes and approaching challenging and complex avalanche terrain with extra caution.
The windy storm continues until Wednesday afternoon.
TUESDAY NIGHT: Scattered flurries with localized accumulations of 5-10 cm, strong southwest wind, temperatures around -4 C.
WEDNESDAY: Flurries continue with another 5-10 cm of snow throughout the day, moderate to strong southwest wind, temperatures around -6 C.
THURSDAY: Partly cloudy, strong south wind, temperatures around -4 C.
FRIDAY: Partly cloudy, moderate south wind, temperatures around -6 C.
Over the weekend there were several reports of natural size 1-2 slab avalanches in east-facing alpine terrain (see some photos here, here, and here). Most of the activity was on wind loaded slopes. Some large whumpfs were reported in the Babines. No persistent or deep persistent slab avalanches have been reported since Dec 22, however there is still potential to trigger large avalanches in steep rocky terrain.
Strong to extreme wind is moving around 30-50 cm of snow that has fallen since New Year's Day. Thick wind slabs can be found in exposed open terrain, sheltered terrain should have mostly low density snow. However, isolated storm slabs could be forming on steep rolls in sheltered areas where recent snow may be settling above surface hoar.
The lower snowpack has two crusts with potentially weak snow around them. One is 60-90 cm below the surface and the other is near the ground. These layers produced avalanches on Dec 21 and 22, but since then have been trending towards dormancy. We are uncertain about how likely it is to trigger avalanches on these deeper layers, but would be most suspect of shallow rocky slopes in the alpine.