Avalanche Forecast

Issued: Mar 19th, 2018 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

While conditions are generally good, there are still some terrain features that warrant caution or avoidance. Mainly steep southerly aspects in the alpine. Additionally, it is the time of year to start early and finish early to beat daytime heating.

Summary

Weather Forecast

Cool temps will remain tomorrow, -1 in the valley and -10 at ridge level. Cloud is expected to return with light accumulations of snow, up to 5cm. The wind is expected to increase to up to 50km an hour at ridge elevation, from the SW.

Snowpack Summary

20-30 cm of recent snow has formed a variable soft slab on some features that is slowly bonding to the underlying surfaces, such as melt freeze crust on solar aspects and older snow layers including facets on shady aspects. Below this the majority of the snowpack is stable and has recently shown no results in tests.

Avalanche Summary

A size 1 avalanche was observed in Unity Bowl near the Lake Louise Ski area today. It was located on a NE aspect at 2500m. Also, yesterday there was a skier accidental size 2.5 on Observation Sub Peak. A group of 3 were descending a steep rocky South aspect when 1 skier triggered the slide and went for a long ride. The party self evacuated.

Confidence

Freezing levels are uncertain on Thursday

Problems

Wind Slabs

This problem has transitioned from Storm Slabs. Recent wind from the NW has been redistributing the storm snow into immediate lee areas in the alpine. The slabs should be visible on the surface as well as being able to feel them with your skis.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

On steep solar terrain the recent storm snow (20-30cm) is sitting on a firm crust. The public has interacted with this 'problem' a couple of times in the last 24 hours. Avoid steep solar slopes in the alpine, especially late in the day.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Mar 20th, 2018 4:00PM