Avalanche Forecast

Issued: Feb 18th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs.

dsaly, Avalanche Canada

South Coast.

New snow and wind are building slabs over a slippery crust. Expect avalanche size and sensitivity to increase as snowfall accumulates.

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system. We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.

Weather Forecast

THURSDAY NIGHT: Snow, 10-20 cm accumulating Friday morning / moderate south-southwesterly wind / ridgeline temperature low -2 / freezing level below 400 m

FRIDAY: Snow, another 5-15 cm though the day / moderate gusting to high southerly wind / ridgeline temperature high -2 / freezing level around 800 m

SATURDAY: Cloudy with flurries, 5 cm / moderate southwesterly wind / ridgeline temperature high -2 / freezing level around 700 m

SUNDAY: Heavy snow or rain, 30-50 cm / high southwesterly wind / ridgeline temperature high +3 / freezing level rising above 1500 m

Avalanche Summary

On Monday, riders found soft low density storm snow rapidly gaining strength and reactivity as temperatures warmed through the day. Slab avalanches size 1-1.5 and 15-30 cm deep released naturally and were triggered by skiers and explosives in the afternoon. There are some tremendous visuals in this MIN report.

Snowpack Summary

15-20 cm fresh snow is expected by Friday morning with more flurries and increasing winds through the day. Accumulating snowfall will cover a widespread crust on most slopes and wind affected surfaces on polar slopes at upper elevations.

An unusual mix of facets, thin breakable crust, and isolated pockets of surface hoar is found 15-30 cm below the surface. This overlies 30-40 cm of gradually faceting snow, over a wide spread and supportive crust underneath. The snowpack is well settled below.

Terrain and Travel

Minimize exposure during periods of heavy loading from new snow and wind.
Closely monitor how the new snow is bonding to the old surface.
Use increased caution at all elevations. Storm snow is forming touchy slabs.

Problems

Storm Slabs

Snowfall accumulating through the day is not expected to bond well to a slippery crust. Southwesterly winds will impact loose snow and build reactive slabs. Expect storm slab size and sensitivity to increase through Friday.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 19th, 2021 4:00PM