Avalanche Forecast

Issued: Mar 5th, 2018 4:47PM

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

Avalanche Canada mbender, Avalanche Canada

Recent new snow combined with wind has promoted wind slab development as well as cornice growth. As the clouds part in the coming days remember that the sun packs a punch this time of year.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

TUESDAY: Mix of sun, cloud and isolated flurries / Light to moderate west wind / Alpine temperature -13WEDNESDAY: Mix of sun, cloud and isolated flurries / Light southwest wind / Alpine temperature -12 THURSDAY: Mix of sun and cloud / Light to moderate southwest wind / Alpine temperature -9  

Avalanche Summary

There was a report from the western portion of the region of a natural size 3.5 deep persistent avalanche approximately 200cm deep on a west aspect starting in the alpine at 2300m running down to 1400m. This was reported on Saturday and occurred in the previous 24-36 hours.

Snowpack Summary

Recent storm snow is settling and has been 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 a low probability to trigger, yet would produce a high consequence avalanche if triggered. We are talking about surface hoar 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

Wind Slabs

An icon showing Wind Slabs
Recent new snow combined with wind has promoted slab development on lee slopes in wind exposed areas.
Give cornices a wide berth when travelling on or below ridges.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

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

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

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 6th, 2018 2:00PM