Avalanche Forecast

Archived

Mar 28th, 2023–Mar 29th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Jasper, Brazeau, Churchill, Cirrus-Wilson, Fryatt, Icefields, Maligne, Marmot, Miette Lake, Pyramid.

Solar warming should primarily factor into your trip planning - avoid exposure to southerly slopes and cornices.

Elevated hazard rating at tree line reflects increasing freezing level and solar influence during peak warming- take advantage of the good overnight freeze by starting and finishing early.

Confidence

Moderate

Avalanche Summary

Cornice failures and loose wet avalanches may increase in the late afternoons (~14:00) with clear skies, direct sun, and rising daytime freezing levels.

Don't forget to post avalanche observations to the MIN.

Snowpack Summary

2-10cm of new snow through the region over a thin sun crust at all elevations on solar aspects. 20-50cm down is a persistent slab, within a variable strength mid-pack which bridges the basal facets and depth hoar at the base. The strength of the mid-pack is varied by aspect and elevation. Snow depth varies from 60-170cm.

Weather Summary

Forecasts call for high freezing levels (up to 2000m) and increasing clouds beginning in the late morning, Wednesday. This should be the warmest day of the week. A mix of sun and cloud on Thursday with a continued diurnal temperature pattern.

Terrain and Travel Advice

Cornices become weak with daytime heating or solar exposure.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

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.

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.