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 2nd, 2020–Feb 3rd, 2020

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, human triggered possible.

Regions

Little Yoho.

Natural avalanche cycle up to size 3.5 throughout the region. Conservative decision making is essential.

Though triggering an avalanche below tree line is unlikely, avalanches from the alpine have been running full path, some reaching valley bottom.

Weather Forecast

Mainly sunny with a chance of isolated flurries on Monday. Temps ranging from -5 to -15 while the winds remain light from the West. Much of the same for Tuesday. Slight warming on Wednesday with 5-10cm of snow forecasted with increasing winds.

Snowpack Summary

30 to 70 cm of recent storm snow at higher elevations, with a rain crust up to 2000m. Wind slabs exist in the alpine and exposed areas at tree line. The Dec 31 layer of facets, surface hoar and sun crust is currently down 50-100cm. The deep persistent basal layer sits 20 to 40cm above the ground and is more developed in shallow snowpack areas.

Avalanche Summary

A widespread natural avalanche cycle occurred on Saturday up to sz 3.5, some of which gouged to ground. Explosive avalanche control throughout the region on Sunday produced results up to sz 3.5, the most notable being Mt. Field which heavily dusted the TCH while the powder cloud rolled up onto Mt. Stephan across the valley.

Confidence

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.