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 5th, 2023–Mar 5th, 2023

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

Regions

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

7 am update: Strong overnight winds from the northeast have likely reverse-loaded fresh wind slabs into atypical terrain features at upper elevations. Keep an eye out for signs of instability like "whumfing", shooting cracks and avalanche activity. There is some uncertainty in reactivity and distribution of buried weak layers.

Confidence

Moderate

Avalanche Summary

Over the past few days several skier triggered avalanches up to size 2.5 have been reported. many of these avalanches failed on weak layers from February and January and occurred at treeline. a few skier triggered wind slabs have also been reported , these avalanches have been near ridge crests on north and east aspects.

Snowpack Summary

Storm totals from the past week average 40 to 60 cm. Expect to find wind slabs on all aspects due to shifting wind direction. This storm snow sits over heavily wind affected surfaces at all elevations.

A layer of surface hoar can be found on shaded slopes, and a sun crust on sun affected slopes buried 40 to 70 cm deep. Another layer from January is buried up to 50 cm below this. These layers has been noted as a failure plane for some avalanche activity.

Otherwise, the snowpack is generally well consolidated and bonding. The lower snowpack includes a layer of weak sugary crystals near the ground. These facets are slowly gaining strength and have not produced recent avalanche activity. We continue to track the layer and watch for any signs that it could wake up and produce very large avalanches.

Weather Summary

Saturday Night

Mostly cloudy with the possibility of light flurries bringing a few centimeters of new snow. Moderate southeast winds and a low of -11°C at 1800 m.

Sunday

Mostly cloudy with the possibility of light flurries bringing a few centimeters of new snow. Light southeast winds and a high of -6°C at 1800 m.

Monday

A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Light southerly winds and a high of -6°C at 1800 m.

Tuesday

Mostly sunny with no new snow expected. Light southwest winds and a high of -6°C at 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Persistent slabs have potential to pull back to lower angle terrain.
  • Surface hoar distribution is highly variable. Avoid generalizing your observations.

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.