Avalanche Forecast

Archived

Feb 21st, 2021–Feb 22nd, 2021

Alpine

Natural and human triggered avalanches likely.

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 unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Jasper.

Icefields Parkway is now closed for Avalanche Control. Anticipated opening on Monday, Feb. 22 at 1800.

Check Alberta 511 for latest updates.

Weather Forecast

Most regions will continue to see westerly ridgetop winds of 70-90km/h. A cold front will push the heavier snow from north to south across the Rockies Sunday. Heavier snowfall will start in the evening with 5-10cm expected during the day, and up to 15cm on Highway 93. Freezing levels will remain near 1800m overnight throughout the Rockies.

Snowpack Summary

Moderate to strong ridge top winds from the SW have created wind slabs or hard surface conditions in alpine and tree line features. In sheltered areas the top 30-60cm is faceted snow over a supportive mid-pack where the snowpack is deeper. Thin snowpack areas are weak, un-supportive, and facetted.

Avalanche Summary

Field teams working in the Icefields and the Tonquin Valley today reporting severe winds, blowing snow, drifting and, poor visibility

Confidence

Wind effect is extremely variable on Monday

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.