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

Apr 27th, 2019–Apr 28th, 2019

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.
Below Treeline
Natural avalanches unlikely.

Regions

Little Yoho.

With 30-40 cm of new snow expected in the high alpine by Sunday, this is a good time to step back in your terrain choices. Stick to moderate angled terrain with minimal overhead hazard until the storm snow begins to bond with the underlying layers.

Weather Forecast

Back to winter with alpine temperatures in the -10 to -15'C range and valley bottoms just above freezing expected for tomorrow. The snow is supposed to finish Saturday night with a mix of sun and cloud expected on Sunday. Winds will remain strong overnight but drop into the light range by late in the day on Sunday as they switch from NE back to NW.

Snowpack Summary

15-20 cm of new snow fell at treeline on Saturday with up to 30-40 cm expected in high alpine areas. Wind loading is present on alpine lee alpine areas from moderate to strong W through NE winds. Supportive crusts exist below this new snow on solar aspects and at lower elevations. Isolated pockets of deep facets still exist on cold north exposures.

Avalanche Summary

Some small storm slabs observed on Saturday. Skier controlled small storm slabs in alpine lee areas reported by the local ski areas during control work on Saturday. One cornice failure on Thursday resulting in injuries to the party skiing below so keep those in mind as well. We expect increased avalanche activity Sunday as the storm slab develops.

Confidence

Due to the number of field observations

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

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.