Avalanche Forecast
Issued: Jan 9th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
zryan,
Avalanche Canada
Continue making conservative terrain choices as the storm snow settles with warm temperatures.
If rain or warm temperatures make the upper storm snow heavy and moist treat the avalanche danger as HIGH and avoid steep slopes and overhead hazard.
Summary
Confidence
Moderate - Uncertainty is due to rapidly fluctuating freezing levels.
Weather Forecast
A noticeable shift in the weather pattern, as warm temperatures embrace the region with continued snowfall throughout the week.
Overnight Sunday: Mainly cloudy with isolated flurries. Ridge wind south, 50 km/h gusting to 75 km/h. Freezing level 600 metres with a weak temperature inversion.
Monday: Flurries, 10-20 cm accumulation. A high of 0°C in the alpine. Ridge wind southwest 55-75 km/h. Freezing levels 600-1200 metres.
Tuesday: Snowing, 25 cm accumulation. Alpine high of 1 °C. Ridge wind south 45-65 km/h. Freezing levels around 1100 metres.
Wednesday: Snowing, 5-20 cm accumulation. Alpine high 0 °C. Ridge wind southwest 25 km/h gusting to 60 km/h. Freezing level around 1000 metres.
Avalanche Summary
On Saturday, numerous natural loose dry avalanches up to size 2 where reported across the region.
On Thursday, operators north of Terrace reported a size 1 skier triggered persistent slab avalanche on an east aspect in an open area at treeline. This avalanche failed on a layer of surface hoar buried at the end of December. There have been no other reports of reactivity on this layer and it seems like a fairly isolated event.Â
Snowpack Summary
Yesterday's storm brought 30-70 cm of new snow, with the highest amounts in coastal areas. Strong southwest winds redeposited this new snow into deep deposits of slab in lee, wind-loaded areas.Â
In sheltered areas, the new snow may have formed a cohesive storm slab or remains loose and unconsolidated.Â
Below the new snow, a previously wind-affected and facetted surface exists from last week's outflow winds and prolonged cold temperatures. This weak layer and hard bed surface may increase the reactivity of the storm snow.Â
The early December rain crust is up to 10 cm thick, down 100-200 cm in the snowpack, and exists to an average of 1400 m in elevation. While this layer has generally gone dormant in the region, it still has the possibility of waking up with new snow load or warming, and wind slab avalanches may still have the potential to step down to this deeper layer in isolated areas.Â
Terrain and Travel
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Avoid freshly wind loaded terrain features.
Problems
Storm Slabs
Saturday evening's 30-70 cm of new snow will continue to settle. In areas that received 30 cm or more of new snow, storm slabs may still be reactive to human triggering. Southwest winds and continued snowfall throughout the day may continue to create deep deposits of slab in wind-loaded areas.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Fluctuation freezing levels on Sunday night and Monday mean that mid-elevations (Low alpine, tree-line) may see periods of freezing rain or rain. Rain could cause the new storm snow to lose cohesion and create dense, wet loose avalanches. If you see warm temperatures or rain making the storm snow heavy and moist, consider the avalanche danger HIGH and avoid steep slopes and overhead hazard. This will mainly be a problem in coastal areas, but could extend as far inland as Terrace and Kitimat.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 10th, 2022 4:00PM
