Avalanche Forecast

Issued: Mar 5th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Loose Wet.

Avalanche Canada bchristie, Avalanche Canada

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The snowpack varies across the region, so start with conservative terrain choices, and watch for signs of instability like recent avalanches, shooting cracks or whumpfs.

Don't let the sun lure you into big features if it's not appropriate for your local conditions.

Summary

Confidence

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

Weather Forecast

Saturday Night: Mostly clear. No new snow expected. Light north ridgetop winds, trending to moderate in the higher alpine. Freezing level falling to valley bottom, alpine low around -10 °C. 

Sunday: Sunny. No new snow expected. Light north ridgetop winds, trending to moderate in the higher alpine. Freezing level at valley bottom overnight, rising to 1500 m through the day. Alpine high around -5 °C.

Monday: Partly cloudy. 0-5 cm of snow expected. Light west ridgetop wind trending to strong northwest in the higher alpine. Freezing level at valley bottom overnight, rising to 1500 m through the day. 

Tuesday: Partly cloudy. 0-5 cm of snow expected overnight, and another 0-5 through the day. Light east wind. Freezing level falling to valley bottom. Alpine temperatures around -15 °C.

Avalanche Summary

On Saturday, near Golden, a naturally triggered size 2 slab avalanche was reported in an open feature around treeline on an east aspect. More details here. West of Invermere, several dry loose avalanches to size 1.5 were reported out of steep, alpine terrain.

On Friday, west of Invermere, a few small, rider triggered storm slab avalanches were reported. A couple failed on a crust on a southwest aspect in the alpine, and the larger two were below treeline on a northwest aspect. Also, near Golden, numerous, small, natural and rider triggered loose dry avalanches were reported, and a size 1.5 avalanche was remotely triggered by a rider in the backcountry near Kicking Horse. More details here.

South of Golden, evidence of a widespread. loose dry and storm slab avalanche cycle during the recent storm up to size 2 was reported. Additionally, avalanche control using large explosives produced several large to very large avalanches, mostly on northerly aspects in the alpine, including one size 3.5 with a crown 60-200 cm deep that is suspected to have failed on a persistent weak layer.  

Snowpack Summary

Watch for the sun heating up the surface snow on steep solar aspects, and increasing the reactivity of settling storm slabs. 

Snowfall amounts have varied substantially throughout the region the last few days, with Panorama and Fairmont being the benefactors of 15 cm of bonus snow on Thursday night. The end of storm totals have ended up fairly similar for most of the region. Winds have been light the last few days, leaving 35-50 cm of unconsolidated snow that is starting to settle, overlying a variety of old surfaces such as firm wind-pressed snow, sun crust on solar aspects, surface hoar, and potential cold weak crystals on shaded aspects. A melt freeze crust may exist within this storm snow, up to 1700 m on all aspects. 

An interface from mid-February is likely now down 40-60 cm. This layer was previously only reactive in wind-loaded terrain where a slab had formed but may become more problematic if covered with a more widespread cohesive slab.

Below that on sheltered north aspects, there is still a surface hoar layer being tracked that was formed in late January. Though there haven't been reports of recent avalanches on this layer in this region, it is still on the radar of many operations.

Terrain and Travel

  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
  • Use small low consequence slopes to test the bond of the new snow.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
  • Loose avalanches may start small but they can grow and push you into dangerous terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

Human triggering of storm slabs should remain on your radar. As the storm snow settles with time, and with the sun warming southerly slopes, slab avalanches could become more likely. 

35-50 cm of recent snow is sitting on generally firm surfaces from the dry period in February. So far, very little avalanche activity has been seen on this layer, possibly due to mostly light winds, and a general lack of slab properties in the upper snowpack. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Loose Wet

An icon showing Loose Wet

With clearer skies forecasted across the region for the weekend, watch for recent, loose snow to become more reactive as the sun warms the surface. 

The recent snow came with very little wind, and the sun is starting to pack a bigger punch at this time of year. Small natural and rider triggered loose snow avalanches are likely.

Aspects: South East, South, South West, West.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 1.5

Valid until: Mar 6th, 2022 4:00PM

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