Avalanche Forecast

Issued: Mar 14th, 2024 4:00PM

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

Avalanche Canada SH, Avalanche Canada

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A significant warmup and an already unreliable snowpack provide the ingredients for an avalanche cycle. Friday may start cooler but the danger will rise quickly, especially on solar aspects.

Through these fluctuating conditions, we will list the highest expected rating of the day.

Summary

Confidence

High

Avalanche Summary

Many large natural avalanches (size 2.5 to 3.5) were observed today in the Lake Louise backcountry (Richardson Bowl, Redoubt), likely triggered by heat. They initiated on persistent layers and then stepped to the ground. Also, a remotely triggered avalanche was reported on the Observation sub-peak without incident today (photos below). It started on the Feb. 3 crust, stepped to the ground, and remotely triggered three size 3 avalanches spanning multiple features.

Snowpack Summary

Moist snow in the valley bottoms on steep solar slopes, and variable crusts are forming daily on solar aspects and lower elevations. On shady aspects up high, there is still dry snow. 50-90 cm of settled snow overlies weaker facets above the Feb 3 crust interface, up to at least 2500 m. The base of the snowpack consists of weak facets. Deeper snowpack areas (west of the divide) are more settled and stronger.

Weather Summary

Friday: Valley bottom freezing levels in the early AM rising to 2600m (high +3C at treeline), light NW winds and sunny.

Friday night: Valley bottom freezing levels except for an above-freezing layer from 2300m to the alpine (aka no freeze!).

Saturday: 3000m+ freezing levels (high +6C at treeline), with light winds and sunny skies.

Sunday: Much the same, maybe warmer.

For more details on the weather, click here.

Terrain and Travel Advice

  • Be alert to conditions that change with aspect and elevation.

Problems

Persistent Slabs

An icon showing Persistent Slabs

50-90 cm of settled snow overlies weak facets above the Feb 3 interface, which is a crust in most areas. Many natural, human, and explosive-triggered avalanches have occurred on this layer in the past week, and the likelihood of avalanches will increase with high freezing levels and sun.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Some recent avalanches have stepped down to the weak facet and depth hoar layers near the base of the snowpack resulting in large avalanches. This seems to be most common in thin, steep, rocky terrain in the alpine, and will likely increase in frequency.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3.5

Loose Wet

An icon showing Loose Wet

The sun's effect and overall higher freezing levels will be more pronounced on Friday, and the likelihood of these avalanches will increase as the day goes on, especially on solar aspects.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Valid until: Mar 15th, 2024 4:00PM

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