Avalanche Forecast

Issued: Feb 13th, 2019 8:06AM

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

ross campbell, Parks Canada

Glacier.

The best skiing and riding conditions exist at and below tree line in sheltered locations. This is also where the January 17th Surface Hoar layer loiters.

Summary

Weather Forecast

Today starts with some clouds and light flurries; proceeded by sunshine as the high-pressure returns, pushing any precipitation south of Rogers Pass. The alpine may reach -14 and winds will be light. The clearing trend continues tonight; and the sun will be back tomorrow, before some snow begins to fall on Friday.

Snowpack Summary

A dusting of new snow covers old hard slabs, and wind scoured surfaces in the ALP and exposed areas of TL. These hard slabs are from Saturday's wind event; strong N-NE winds reverse loaded any available snow onto solar aspects, over a thin sun crust. The Jan 17th PWL is buried approximately 50-70cm at TL and below.

Avalanche Summary

On Saturday there was a natural cycle triggered by strong N-NE winds. Since the weekend we have only seen sporadic small wind slabs triggered by skiers up to size 1.5 in the alpine. There have been no reports of new avalanches on the Jan17th PWL in over a week.

Confidence

Problems

Wind Slabs

Recent strong to extreme NE winds have redistributed storm snow into hard wind slabs and loaded pockets on lee features. On southerly aspects, wind slabs are poorly bonded to a buried crust.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious in shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Jan 17 Surface Hoar layer is buried 50 to 70cm at and below tree line. This interface exists on all aspects and most reactive between 1400-1900m; especially on steep solar aspects where it overlies a crust.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 14th, 2019 8:00AM