Avalanche Forecast

Issued: Jan 12th, 2019 8:00AM

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

Parks Canada andrew jones, Parks Canada

Watch for slab development and increased avalanche hazard as the forecasted above freezing temperatures arrive today.

Summary

Weather Forecast

Warm southern air rides a wave of high pressure into the Rogers Pass area for the weekend. We will likely see a temperature inversion establish with above freezing temps in the alpine. For today, a mix of sun and cloud, no precipitation and ridge winds south 15km/h.  Freezing levels climb to 1900m with an alpine temperature of 1.0.

Snowpack Summary

Recent storm snow has begun to settle out into soft slabs at all elevations. Isolated wind slabs exist in the alpine in exposed areas and near ridge lines. The Jan 2 freezing rain crust is down ~90cm. The Nov 21st interface is now 1-2m in deep. The expected arrival of above freezing temperatures will accelerate slab development.

Avalanche Summary

No new avalanches were observed yesterday.

Confidence

Freezing levels are uncertain

Problems

Storm Slabs

An icon showing Storm Slabs
Recent snowfall combined with winds and mild temps has create storm slabs. Warm temperatures will increase slab properties and destabilize the surface snow, thereby increasing the likelihood of triggering this widespread problem.
Daytime warming will weaken surface layers.Watch for signs of slab formation, such as whumpfing and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 2.5

Persistent Slabs

An icon showing Persistent Slabs
A recent size 3.5 skier triggered avalanche in Camp West path ran on this layer. The likelihood of triggering deeper layers increases with warming air temperatures. Cornices, which are also temperature sensitive, can certainly trigger this problem.
Avoid steep convexities or areas with a thin or variable snowpack.Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2.5 - 3.5

Valid until: Jan 13th, 2019 8:00AM