Avalanche Forecast

Archived

Jan 1st, 2019–Jan 2nd, 2019

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Jasper.

Snowpack depths and avalanche problems vary significantly through out the forecast region. Re-assessment is essential if you are venturing into new areas.

Weather Forecast

A ridge of high pressure to our south gets pushed out by a frontal system later in the week. Wednesday: mostly cloudy with isolated flurries. Alpine temps high -8C, low -10C. Winds will be L-M SW.Snowfall Wed. night through Friday with total accumulations of up to 50cm.A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

35cm of low density snow that fell in the southern half of the region on Saturday. Strong to extreme SW winds during the storm produced widespread wind effect in any open terrain. The Dec. 11th interface is still easily identified down 50-110cm and continues to produce hard but sudden test results, and was reactive to large triggers recently.

Avalanche Summary

Little natural activity noted on Monday's field trip to E facing slopes across from Mt. Coleman and visibility was good. One recent large avalanche in the Boundary area likely failed on the Dec. 11th interface, and scrubbed to ground in places. Sunday's avalanche control produced loose dry avalanches to size 1.5 on the immediate roadside targets.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

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.

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.