Avalanche Forecast

Issued: May 4th, 2023 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Deep Persistent Slabs, Cornices and Loose Wet.

Avalanche Canada TH, Avalanche Canada

The hot weather will persist for one more day before freezing levels show an appreciable drop as weather approaches. Dangerous avalanche conditions will persist at least until this change occurs.

Hikers and scramblers: expect poor travel and avoid all avalanche terrain.




Avalanche Summary

A widespread natural avalanche cycle to size 4 continues with avalanches failing on the ground on all aspects and elevations, many running to the valley bottom. This is the biggest avalanche cycle of the season. Click the link's for recent avalanche info on the Plain of Six Glaciers and Lake Louise area.

Snowpack Summary

The heat has penetrated the snowpack and destabilized it at all elevations. Warm temperatures overnight have prevented all but superficial refreezing.

Expect snow on all aspects at all elevation to be unsupportive isothermal (slush).

Weather Summary

The ridge of high pressure that has dominated for a week has started to break down with unstable air allowing for afternoon thundershowers and spotty rain over the last two evenings. High freezing levels will remain Thursday evening with overnight clearing bringing sunny skies in the AM for one more kick at 3500m freeze levels Friday.

Clouds will work their way in Friday afternoon and lead to light rain as freezing levels drop to 2500m overnight that will turn to snow at alpine elevations.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of intense solar radiation.
  • Avoid exposure to overhead avalanche terrain as temperatures increase.


Deep Persistent Slabs

An icon showing Deep Persistent Slabs

We are seeing lots of avalanche activity on the weak facets and depth hoar at the bottom of the snowpack as the upper snowpack heats up and looses cohesion. These avalanches are easily triggered, often large and running long distances.

Aspects: All aspects.

Elevations: Alpine, Treeline.


Very Likely - Certain

Expected Size

2 - 3.5


An icon showing Cornices

With the high freezing levels and direct sun exposure, the mountains will begin to shed. Do not expose yourself to any corniced features or steep slopes below cornices as the day heats up.

Aspects: All aspects.

Elevations: Alpine.



Expected Size

1.5 - 2.5

Loose Wet

An icon showing Loose Wet

We expect wet slabs and wet loose avalanches on all aspects and elevations, especially when the sun cooks the slopes. Slush and wet snow will run like water down gullies and through rock bands: the spring melt is on.

Aspects: All aspects.

Elevations: All elevations.



Expected Size

1 - 2.5

Valid until: May 5th, 2023 4:00PM