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 8th, 2021–Mar 9th, 2021

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

Regions

Banff Yoho Kootenay.

Two large avalanches on opposite ends of  the region over the past 24 hours likely involved the persistent slab problem. Events such as these may be  low likelihood  but would yield consequence and should be carefully weighed in decision making .

Weather Forecast

With mainly clear skies, a strong freeze is expected Monday night. As west winds pick up to the moderate range in the alpine Tuesday, minimal heating is expected despite clear skies. Clouds will develop overnight Tuesday leading to milder morning temperatures and the potential for flurries through the day Wednesday. Clearing overnight into Thursday

Snowpack Summary

Since Friday, up to 30 cm of recent snow sits over solar crusts and wind effect in open areas. New solar crusts on isolated steep slopes formed on Monday. Two persistent facet layers (Feb 19 & Jan 27) are down 30-80cm and still producing sudden shears in some locations. In thin areas the basal depth hoar/crust from Nov is still quite prominent

Avalanche Summary

Two large events were observed in the past 24 hrs. A size 3 cornice triggered slab ran between the 4rth and 5th buttresses of Rundle Sunday, and a large powder cloud was observed off of Mt. Lefroy into the Death Trap from Lake Louise Monday. Both of these events seem to have involved the persistent layers.

Confidence

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.