Avalanche Forecast

Issued: Feb 28th, 2018 4:48PM

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

Avalanche Canada istorm, Avalanche Canada

Storm slabs on steep slopes, wind slabs on lee slopes and a persistent slab that seems to be "waking up". Lots to manage but also lots of good snow to ride! WInd protected areas are your best bet.

Summary

Confidence

High -

Weather Forecast

Low pressure off the coast is drifting south, which sets the stage for colder drier Alberta air to slide into the forecast region.THURSDAY: Flurries or light snow. Light to Moderate east or southeast wind. Treeline temperatures around -5 to -10 CFRIDAY: Flurries. Northeast winds dropping to light during the day. Temperatures around -10 C.SATURDAY: Similar to Friday but more sun and a few degrees cooler.

Avalanche Summary

Most operations reported "no new avalanches". Recent avalanche activity has consisted of mainly loose dry in the size 1-1.5 range but also some wind slabs to size 2 in alpine terrain. These were either naturally occurring or intentionally triggered. Deep persistent avalanche activity has become less frequent over the past week.

Snowpack Summary

Around 60 cm of recent storm snow is being redistributed into slabs in wind-exposed terrain. Below this is a layer buried mid-February that presents as a sun crust on solar aspects, and spotty surface hoar on sheltered slopes. This layer looks most concerning on on solar aspects where it's associated with with small facets or surface hoar above.There are several deeper layers in the mid-pack that have shown signs of improving but remain on the radar as low probability - high consequence avalanche problems. I'm talking about surface hoar layer buried back in December and January. Near the base of the snowpack is a November crust combined with loose sugary snow. These layers may "wake-up" with strong inputs such as sustained warming, sustained snowfall, large triggers (e.g. cornice fall, smaller avalanches coming down from above); human triggering is also possible in shallow snowpack areas with variable snow depth and convoluted terrain.

Problems

Storm Slabs

An icon showing Storm Slabs
New snow and wind created slabs on lee slopes in wind exposed areas. Steep slopes and convex rolls in wind sheltered areas are a concern; still, wind protected areas are your best bet for good riding.
Be cautious as you transition into wind affected terrain.Use caution on steeper open slopes and convex rolls in wind sheltered areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs
Buried weak layers exist within the snowpack and may be reactive to large triggers such as a cornice fall. Human triggering may also be possible in shallow or thin, rocky, unsupported terrain.
Watch convoluted terrain with variable snowpack depth and multiple trigger points.Pay attention to overhead hazards like cornices which could trigger persistent slabs.Carefully assess and consider avoiding southerly facing slopes

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 1st, 2018 2:00PM