Avalanche Forecast

Issued: Feb 13th, 2017 8:10AM

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

Parks Canada dean flick, Parks Canada

Warm temperatures and strong solar radiation may destabilize the snow today. Weak layers in the snowpack are more likely to fail as slab avalanches on slopes that are exposed to a lot of sunshine. Avoid exposure below cornices receiving direct sun.

Summary

Weather Forecast

A high pressure ridge moving up from Washington State, will bring warm temperatures and lots of sun with some cloudy periods today and tomorrow. The freezing level will be around 2000m today and 2700m tomorrow. Ridge winds southwest 10-25km/h and no snow forecast.

Snowpack Summary

Storm snow is settling, but snowpack tests still show weak layers down 20 and 50cm. Yesterday, a field team had sudden planar test results and a RB4 (Whole Block) down 80cm. On Friday whumphing was observed at tree line on a higher density layer over lighter snow. Cornices could fail from strong solar input and loose moist avalanches are likely.

Avalanche Summary

Most recent storm slab avalanches in the hwy corridor were 4 size 1.5 to 2.5 on S and N aspects. Yesterday, on steep southerly aspects, a few size 1.0, loose moist slides were observed. On Avalanche Crest yesterday, some ski touring public reported, shooting cracks, whumphing and hollow drum like sounds - OBVIOUS signs of instability!

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs
Widespread reactive storm slabs have formed from previous heavy snowfall and strong winds overnight! If triggered they have potential to run full path. Reports came in of whumphing & low elevation slabs releasing below treeline yesterday.
New snow will require several days to settle and stabilize.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
The Jan 25th sun crust is buried down approx 60cm. Previous to the storm it was whumphing, showing easy sudden results and reactive to human triggering. If the storm slab is triggered it has the potential to step down and trigger this layer.
Watch for whumpfing, hollow sounds, and shooting cracks.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Feb 14th, 2017 8:00AM