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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Use extra caution on sunny slopes, and consider the consequences of small avalanches in steep or exposed terrain. Avalanche activity is tapering off after a stormy period, but it's probably not time to center-punch that big feature you've been looking at all year. 

Summary

Confidence

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

Weather Forecast

General cooling and clearing trend with cold northern air providing good refreezes overnight, but upslope flow will continue to bring spotty cloud cover and bits of snowfall through the forecast period.

Saturday Night: Partly cloudy. 2-5 cm of snow expected. Light northwest ridgetop wind, trending to moderate north at higher elevations. Freezing level falling to valley bottom. Treeline low around -10 °C.

Sunday: Localized cloud in the early morning, sunny the rest of the day. No new snow expected. Light variable ridgetop wind, trending to moderate north at higher elevations. Freezing level rising to 1500 m. Treeline high around -5 °C.

Monday: Partly cloudy. Possible trace of snow expected. Light to moderate west ridgetop wind, trending to strong northwest at higher elevations. Freezing level rising to around 1500 m. Treeline high around -3 °C.

Tuesday: Partly cloudy. Around 7 cm of snow expected overnight, and another 0-4 cm through the day. Light east ridgetop winds. Freezing level dropping to valley bottom. Alpine temperatures around -13 °C.

Avalanche Summary

On Saturday, south of Crowsnest Pass, a few small, rider triggered loose dry avalanches were reported on sunny slopes.

On Friday, numerous natural, rider triggered, and explosive triggered dry loose avalanches up to size 1.5 were reported in the new storm snow.

On Thursday, small, loose dry avalanches were reported in the recent storm snow. Also, south of Crowsnest Pass, one size 2 explosive controlled avalanche was reported, starting as a storm slab, and getting larger as it entrained loose new snow lower on the slope.

Snowpack Summary

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

20-35 cm of new snow fell with light winds overnight on Thursday and into Friday morning. A melt freeze crust may be present underneath this new snow, on all aspects, and reported as high as 2100 m.  

Snowfall amounts have varied substantially since the start of the week with south of highway 3 receiving 30-50 cm and the north getting 10-20 cm. This fell as rain at lower elevations, so expect moist snow underneath the melt freeze crust. 

The recent storm snow still needs time to bond to a variety of old surfaces such as firm wind-pressed snow, sun crust on solar aspects, and potentially weak, sugary crystals buried in late February.

The middle and lower snowpack are generally well consolidated, with a crust/facet layer from early December found near the ground. It is currently considered dormant but could become active later this season. 

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Start with simple terrain and gather information before thinking about more committing features.
  • Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.
  • Loose avalanches may start small but they can grow and push you into dangerous terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slab avalanches are becoming less likely, but they have recently been more reactive where slabs sit on top of crusts or cold sugary crystals.

Continue to make conservative choices and give the storm snow time to settle and stabilize.

The first punch of sun after the storm could make storm slab avalanches more likely, use extra caution on slopes facing the sun. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

With clearer skies forecasted across the region on the weekend, watch for the 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