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 3rd, 2023–Feb 4th, 2023

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

Kootenay Boundary, Bonnington, Grohman, Kootenay Pass, Norns, Rossland, South Okanagan, Ymir, Moyie, St. Mary.

Use extra caution on wind-loaded slopes and near ridgetops. Continued snowfall and southwest wind is building reactive wind slabs. Deeper weak layers have not produced recent avalanches, but encourage adding an extra layer of caution to your decision making.

Confidence

Moderate

Avalanche Summary

Riders and explosives continue to trigger small (size 1 to 1.5) loose dry and wind slabs within the recent storm snow. Wind slabs may remain active in steep lee and cross-loaded terrain at higher elevations.

Continue to avoid shallow, rocky areas where the snowpack transitions from thick to thin, as these are the most likely areas to trigger deep weak layers.

Snowpack Summary

10 to 15 cm of recent soft snow has been blown into wind slabs in cross-loaded and lee terrain features from sustained southwest wind. This snow rests on small surface hoar crystals in wind-sheltered terrain. The surface hoar rests on previously wind-affected snow at higher elevations, faceted soft snow in wind-sheltered terrain, and a melt-freeze crust on sun-exposed slopes and below approximately 1800 m.

A surface hoar layer buried in early January is 40 to 80 cm deep. Its distribution is spotty, but it can still be found in wind-sheltered and shaded terrain features.

The lower snowpack contains weak and faceted grains.

Weather Summary

Friday Night

Cloudy. 2-5 cm of snow expected. Moderate southwest ridgetop wind. Treeline temperature around -7 °C.

Saturday

Cloudy. 0-3 cm of snow expected. Moderate southwest ridgetop wind, becoming light south by the afternoon. Freezing level rising to between 1250 m and 1500 m.

Sunday

Mostly cloudy. 2-10 cm of snow expected, on the higher end in the west side of the forecast region. moderate west and northwest ridgetop wind. Freezing level around 1500 m.

Monday

Mostly cloudy. Possible trace of snow expected. Moderate to strong west and southwest ridgetop wind. Freezing level around 1250 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Approach lee and cross-loaded slopes with caution.
  • Wind slabs are most reactive during their formation.
  • Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.