Avalanche Forecast

Issued: Apr 17th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Loose Wet and Cornices.

Avalanche Canada ahanna, Avalanche Canada

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Start (and finish) your day early and avoid exposure to sun-exposed avalanche terrain. Look for high elevation north facing objectives without cornices overhead, and plan your egress route carefully.

Check out the Forecaster's Blog for more on managing spring conditions.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

A ridge of high pressure, with sunny skies and high freezing levels continues to dominate the weather pattern on Saturday. Sunday may bring a cooler, cloudier day.

Saturday night - Clear / light wind / alpine low temperature near +5 / freezing level 3000 m 

Sunday - Sunny / moderate northeast wind / alpine high temperature near +5 / freezing level falling to 2500 m

Monday - Sunny / light wind / alpine high temperature near 0 / freezing level 2400 m

Tuesday - Sunny / light wind / alpine high temperature near 0 / freezing level 2400 m

Avalanche Summary

There have been several natural wet loose and glide slab avalanches up to size 2.5 reported in recent days, as well as several natural cornice failures up to size 3.

Looking forward, wet loose avalanches and cornice failures are expected to continue with sun and warm temperatures. The likelihood and potential size of these increases when temperatures do not dip below freezing overnight, and avalanche activity will likely begin earlier in the day with each subsequent warm day.

Wind slabs may still be possible to trigger on high elevation north aspects.

Snowpack Summary

High overnight freezing levels mean that the snow surface remains moist or wet in many areas. In places where the surface forms a crust overnight, it should quickly soften during they day with sunshine and warm temperatures. The highest elevation north aspects may still hold soft snow or wind slabs.

Cornices are large and looming along ridgelines. Sun and warm temperatures will increase the chances of cornice failures, especially when temperatures remain above zero overnight.

Terrain and Travel

  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
  • Avoid exposure to sunny slopes, especially in the afternoon.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Avoid areas with overhead hazard, especially solar aspects.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

Loose Wet

An icon showing Loose Wet

The snow will quickly lose cohesion and become unstable with sun and warm temperatures.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Cornices

An icon showing Cornices

Cornices are large and looming along many ridgelines. They grow increasingly unstable during periods of warming.

Aspects: North, North East, East, West, North West.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Apr 18th, 2021 4:00PM