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

Mar 28th, 2024–Mar 29th, 2024

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

Regions

Banff, East Side 93N, Kootenay, LLSA, Sunshine.

Triggering the Feb 3 persistent weak layer remains the greatest concern. Use caution in areas with a snowpack depth lower than 200cm on shaded slopes above 2000m where several recent events have been triggered.

Expect to find developing new slabs with the incoming snow and winds.

Confidence

Moderate

Avalanche Summary

In the last week, there has been four size 2-3 avalanches that have all been remotely or accidentally triggered by skiers. All occurred on northerly aspects between 2000 - 2600m in thin snowpack areas.

These have all initiated on the Feb. 3rd crust/ facet interface and stepped down to basal facets / ground.

Be cautious on north slopes if there is no March 20 crust underfoot and the snowpack is less than 200cm. Infact: run away if the snowpack is less than 150cm!

Snowpack Summary

Up to 15cm of storm snow covers sun crusts on solar aspects and up to 30 cm of dry snow on shaded slopes. Below this, the March 20th crust exists everywhere except north aspects above 1800.

Our main concern is thin snowpack areas (read: 200cm or less) on northerly aspects where there is no March 20 crust. Here the mid-pack Feb 3 facet / crust layer and the basal facets / depth hoar remain sensitive to triggering.

Deeper snowpack areas have fewer concerns.

Weather Summary

Thursday evening: light snowfall will linger with freezing levels to valley bottom. Light to moderate SW winds at ridgetop.

The same light snowfall will continue Friday with freezing levels near 1500m and winds shifting NW.

Scattered flurries Saturday.

Skies clear and freezing levels rise to 2000m Sunday as winds increase: moderate to strong.

Click here for more weather info.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.

Problems

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.

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.