Avalanche Forecast

Issued: Mar 21st, 2018 4:22PM

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

swerner, Avalanche Canada

Northwest Inland.

Storm slabs will build throughout the day. A CONSIDERABLE hazard may be the story in the am. Bump the hazard to HIGH in the alpine if you receive more than 25 cm of new snow by the afternoon.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Overnight Wednesday: 5-10 cm of new snow with strong easterly winds. Freezing level valley bottom.Thursday: Snow amounts 10-25 cm with strong northeast-east winds. Freezing level valley bottom. Friday: Cloudy with isolated flurries. Ridgetop winds moderate from the East. Alpine temperatures near -8 and freezing level at valley bottom.Saturday: Mostly cloudy with some sunny periods. Ridgetop winds light/ gusting strong from the southwest. Freezing levels near 900 m.

Avalanche Summary

No recent avalanches have been reported. With forecast snow and wind you can expect the avalanche hazard to rise.

Snowpack Summary

Variable snow surfaces exist including dry snow, surface hoar, crusts and moist snow at lower elevations. High elevation, north aspects may have lingering wind slabs in immediate lee features which sit on surface hoar and/ or a sugary facet layer found down 10-30 cm. The forecast storm snow over the next 2 days will likely have a poor bond to these older snow surfaces. A surface hoar and crust layer from January is buried around 80 to 140 cm in the southwest of the region. This layer still has the potential to be triggered from a thin snowpack spot, or with a large trigger like a cornice fall.Sugary facets exist at the bottom of the snowpack in steep, rocky, and shallow snowpack areas.

Problems

Storm Slabs

The forecast storm snow will bond poorly to the plethora of old snow surfaces. It will likely step down deeper to the surface hoar layer buried March 9th. Uncertainty remains around the distribution of this layer.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.Stick to simple terrain and be aware of what is above you at all times.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Mar 22nd, 2018 2:00PM