Avalanche Forecast

Archived

Apr 8th, 2023–Apr 9th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

A weak overnight freeze tonight followed by 10-15mm of precipitation will rapidly increase the avalanche hazard throughout the day on Sunday.

Maligne Lake Rd will be closed tomorrow due to wet loose avalanche conditions. The Icefields Parkway will be closed from 15:00-20:00h for avalanche control. Check AB 511 for road status updates and be sure to confirm the Icefields Parkways is open before planning any travel Sunday PM- Monday.

Confidence

Moderate

Avalanche Summary

A few natural wet loose avalanches up to size 2 were observed yesterday in the Stutfield glacier drainage and in the Fryatt area. Limited visibility near Parkers Ridge today.

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

Snowpack Summary

Sunday's precipitation will continue to build wind slabs in the alpine but will transition to rain at lower elevations. On Saturday, the surface snow was moist up to 2000m. Under this, a sun crust exists at all elevations on solar aspects. The mid-pack consists of multiple layers of dense wind effected snow, sun crusts, and facets. Depth hoar and basal facets make up the base of the snowpack.

Weather Summary

Sunday

Periods of snow.

Accumulation: 15 cm.

Ridge wind southwest: 25 km/h gusting to 65 km/h.

Freezing level: 2200 metres.

Monday

Flurries.

Accumulation: 10 cm.

Ridge wind southwest: 15 km/h gusting to 70 km/h.

Freezing level: 1800 metres.

Tuesday

Flurries.

Accumulation: 8 cm.

Alpine temperature: Low -9 °C, High -3 °C.

Ridge wind west: 10-30 km/h.

Freezing level: 1700 metres.

Terrain and Travel Advice

Minimize exposure during periods of heavy loading from new snow, wind or rain.
If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.

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.

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.

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.