Avalanche Forecast

Issued: Apr 11th, 2017 3:37PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Cornices.

mgrist, Avalanche Canada

Northwest Inland.

Strong easterly winds on Tuesday-Wednesday may result in unusual snow loading patterns. Cornices are large and remain a significant concern.

Summary

Confidence

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

Weather Forecast

Light precipitation and STRONG easterly winds on Tuesday-Wednesday. Unsettled weather and cool temperatures thereafter. WEDNESDAY: Mix of sun and cloud with occasional flurries (5-15cm possible). Strong easterly ridgetop winds. Freezing level around 1500 m.THURSDAY: Mainly cloudy with isolated flurries (2-5cm). Moderate southeasterly ridgetop winds. Freezing level around 1400 m.FRIDAY: Cloudy with scattered flurries (3-5cm). Light southerly ridgetop winds. Freezing level around 1300 m.

Avalanche Summary

On Monday, several loose wet avalanches to Size 2.5 were reported in the afternoon with solar input in the north of the region. Also in the north, a cornice failure on a northwest aspect resulted in a slab avalanche, Size 3.0.

Snowpack Summary

Small amounts of new snow (3-10cm) fell in the past three days. Winds were light to moderate (south through northeast) and may have created small wind slabs on lee features below alpine ridgetops. The new snow will likely be sitting on hard surfaces created by strong winds last week.Elevations below roughly 1300 m are experiencing a daily melt-freeze cycle and the snowpack is likely isothermal. The February crust and facet layer is 70-90 cm deep in the Houston Telkwas sled area and a deep persistent faceted weak layer is still lingering near the bottom of the snowpack in all areas.

Problems

Wind Slabs

Small amounts of new snow and moderate to strong east winds may result in unusual loading patterns in lee features below ridgetops.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.

Cornices become weak with daytime heating, so travel early on exposed slopes.Give cornices a wide berth when travelling on or below ridges.Minimize exposure to overhead hazard from cornices.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 12th, 2017 2:00PM