The weather is kicking off the year with a wild storm! You could kick off the year by chilling out for a day or two. I bet that a ski resort or safe-access meadow braapping would be great fun:) Large to very large natural avalanches are likely.
A weak layer of facets above a crust that formed in early December is likely now 100-225 cm deep.
While this layer has been less active recently, rapid loading from the new storm could wake it up, and the consequences would be large.
The most suspect terrain would be shallow rocky start zones at elevations between 1800-2100 m.
With heavy snowfall, high wind, and warming temperatures, we expect many large to very large natural avalanches. Human triggered avalanches will be very likely in these conditions.
A stormy few days to start 2022! Weather forecast models are not agreeing on the exact timing or intensity of the storm, so keep a constant eye on weather and snowpack conditions if you are in the backcountry.
Saturday Night: Overcast. 20- 45 cm of snow expected. Moderate to strong south winds trending to extreme at higher elevations, possibly over 100km/h. Freezing level rising as high as 400 m.
Sunday: A stormy day. Another 20-40cm of new snow accompanied by moderate to strong south winds, trending to extreme at higher elevations. Freezing levels rising to 700m by mid afternoon, but due to heavy snowfall, the rain/snow line could be a few hundred meters lower.
Monday: Another 20-40 cm of snow overnight before the storm eases to lighter snowfall. 5-10 cm through the day. Light southeast wind trending to strong southwest at higher elevations. Freezing levels falling to around 250 m.
Tuesday: Mostly cloudy. 5-15 cm of snow expected. Light southeast winds trending to strong southwest at higher elevations. Freezing level falls back to valley bottom.
With heavy snowfall, high wind, and warming temperatures, we expect many large to very large natural avalanches. Human triggered avalanches will be very likely in these conditions.
On Friday, professional operations reported natural and explosive triggered cornice failures up to size 2 that triggered small slab avalanches on the slopes below.
On Thursday, size 1 wind slabs were reactive to human triggering in the Whistler area.
We have been paying close attention to the early December crust, which has formed a persistent weak layer in the region. The last reported avalanche on this layer was on Dec 24, but it produced several notable avalanches around Dec 16 at elevations between 1800-2100 m. This size 2.5 skier-triggered avalanche occurred on a northwest facing slope around 2100 m in the Blackcomb backcountry, and propagated between some shallowly buried rocks.
Learn more about how this persistent weak layer is developing in our latest forecaster blog!
50-70 cm of new snow is forecast to fall as temperatures rise and strong to extreme southwest winds blow. This is a recipe for unstable avalanche conditions.
This new snow falls on top of a variety of cold, low density, wind affected, or facetted snow surfaces, and it is not expected to bond well.
Other potential weak layers could now be buried up to 100 cm deep. This includes a layer of near-surface facets and in isolated areas surface hoar, formed by the persistent cold temperatures earlier in the week. In sheltered areas, a layer of low density, facetted snow may be preserved.
A weak layer of facets (sugary snow) can be found over a widespread crust that formed in early December (now probably down 100-225 cm). This layer has been most reactive at treeline and low alpine elevations, between 1800-2100 m.
Although we have seen a decreasing trend in avalanche activity on this layer, it has still produced some notable human triggered avalanches over the past week. This problem is particularly hard to predict and poses a tricky low-probability high-consequence scenario.
The lower snowpack is well settled. Snowpack depth at treeline ranges from 200-300cm.
