Avalanche Forecast
Issued: Apr 18th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
dsaly,
Avalanche Canada
Be mindful of reactive slabs forming with new snow, the deepest deposits will be in areas loaded by wind. Bump the hazard to Considerable if you find more than 20 cm fresh snow in your riding area.
Summary
Confidence
High - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.
Weather Forecast
MONDAY NIGHT: Cloudy with flurries, 5-10 cm. Treeline low -8 C. Increasing southeast wind, 25-40 km/h.
TUESDAY: Cloudy with snow and wet flurries above 1600 m, 5-10 cm. Treeline temperatures rising to -3 C. 25-50 km/h wind from the northwest.Â
WEDNESDAY: Partially cloudy. Treeline temperatures rising to -2 C. Light wind from the southeast.Â
THURSDAY: Partially cloudy, isolated flurries. Treeline temperatures rising to -1 C. Light winds from the southeast.Â
Avalanche Summary
Reports over the last week documented large cornice falls in alpine terrain, some of which have triggered large slab avalanches (size 2-2.5) on the slopes below. The most avalanche activity has been noted around Valemont and Blue River.Â
Snowpack Summary
At treeline and higher, fresh snow will cover old wind slab and wind press, and 20-50 cm of old snow. This sits on a melt-freeze crust all aspects to 2000 m and mountain tops on solar aspects. Another prominent crust layer is found 40-70 cm deep.Â
Cornices are very large and exposure to slopes beneath them should be minimized, especially if the weather is sunny, warm, or windy. The snowpack deteriorates rapidly at lower elevations.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs may be poorly bonded to the underlying crust.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
Upwards of 15 cm flurries is forecast to accumulate by the end of Tuesday, with localized areas getting up to 25 cm. New snow is not expected to bond well with the old surfaces, particularly on the old crust. Expect slab reactivity to increase through the day, especially in wind-loaded terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices may be weak and reactive to human triggers. Give them a wide berth when travelling on ridges. They are a significant hazard alone and may produce large slab avalanches as they fall onto the slope below. Cornice falls are more likely when the weather is sunny, warm, or windy.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 19th, 2022 4:00PM
