Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 27th, 2022–Feb 28th, 2022

Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

Kootenay Boundary.

Avalanche danger will increase throughout the day with heavy snowfall, southwest wind and rising freezing levels. 

Avoid avalanche terrain during periods of heavy loading from new snow and wind.

Confidence

Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather. Uncertainty is due to the timing, track, & intensity of the incoming weather system.

Weather Forecast

There is some model disagreement around the timing and intensity of the next system. 

Sunday night: Snowfall 10-15 cm, moderate to strong southwest wind, treeline low around -5 °C.

Monday: Snowfall 20-35 cm, moderate to strong southwest wind, treeline high around 0 °C, freezing levels climbing rapidly and could reach over 2000 m by late Monday night.

Monday night: Heavy precipitation continues overnight with 20-40 mm possible with strong southwest wind. Freezing levels around 2000 m.

Tuesday: Snowfall easing during the day, moderate to strong SW wind, freezing levels dropping slightly to 1800 m.

Wednesday: Light snowfall, light to moderate southwest wind, treeline high hovering around zero.

Avalanche Summary

On Saturday a skier remotely triggered a large (size 2) wind slab over a crust just north of the region. Last week riders triggered wind slabs, as well as at least two size 2 persistent slabs involving the mid-January surface hoar layers in the east of the region.

Snowpack Summary

By the end of the day on Monday new storm slabs will have buried highly variable snow surfaces which include wind-affected surfaces in exposed terrain, a thin sun crust on solar aspects which may be faceting, surface hoar in sheltered areas, and/or old storm snow on shaded slopes which may be faceting. 

A weak interface from mid-February was down around 20-30 cm prior to the storm. It consists of a sun crust on solar aspects, facets, and/or surface hoar. This layer was previously only reactive in wind-loaded terrain where a slab had formed but it is expected to become a more widespread problem as the storm progresses and creates a more widespread slab.

Two layers of buried surface hoar from January were down around 40-70 cm prior to the storm. Most recently, this surface hoar was most reactive in sheltered areas around treeline in the east of the region, and appeared to be dormant through the rest of the region. As the storm progresses and more load is added to the snowpack, this surface hoar will get tested and avalanches have the potential to step down to these deeper layers. 

Terrain and Travel

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Avoid all avalanche terrain during periods of heavy snowfall.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.