This is an archived advisory related to a fatality near Lake Louise Mar 14, 2025

Date Issued: Friday, March 14, 2025 at 03:00
Valid Until: Saturday, March 15, 2025 at 03:00
Prepared by: Parks Canada

Since March 9th, 30-90 cm of snow has fallen, nearly doubling the snowpack in areas like Bow Summit. Recent reports of whumps, remote triggers, and natural avalanches mean human triggering remains very likely. Stick to low-angle terrain and avoid overhead exposure until conditions improve.

Danger Ratings
Friday
Alpine: 4 - High
Treeline: 3 - Considerable
Below Treeline: 3 - Considerable

Terrain and Travel Advice

- Make conservative terrain choices and avoid overhead hazard.
- Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.

Problems

Avalanche Problem 1: Persistent slab
All Elevations, All Aspects
Chances of Avalanches: Very likely
Expected Size: Large - Very large

In many areas, the storm snow has overloaded the persistent layers (see snowpack summary) in the mid and lower pack, resulting in very large avalanches.

Avalanche Problem 2: Storm slab
All Elevations, All Aspects
Chances of Avalanches: Very likely
Expected Size: Small - Large

Since Saturday, 30-90 cm of storm snow and strong southerly winds have created storm and wind slabs at all elevations. More snow fell in the northern forecast area (Bow Summit). Settlement of the surface snow means a stiffer slab is forming, potentially allowing wider propagations.

Avalanche Summary

There was limitied visibility in many areas today. Sunshine was a ski-cutting size 1-1.5 storm slabs (30-60cm deep) in the Delerium dive today; all reloads that had formed since the AM.

Since Saturday, there have been many natural avalanches up to size 3 and human-triggered avalanches. Most of the activity appears to be happening East of the divide, but there have been fewer observations in deeper snowpack areas to the West.

Snowpack Summary

10-15cm in the past 24 hours and 30-90cm since March 9th, with the most snow in the Bow Summit region, along the Wapta, and in Little Yoho. Strong S winds have formed slabs over sun crusts on steep S aspects or firm wind-affected snow elsewhere.

A persistent weak layer (Feb 22/Jan 30 facets) is buried 50-100 cm deep. In shallower eastern areas, the mid/lower snowpack is very weak with facets and depth hoar, while deeper western areas are more consolidated.

Weather Summary

Thursday night: 5-15cm
Friday: Trace snow, light-mod winds and cooler temperatures (-9 to -12C.)

Confidence
High. The number, quality, or consistency of field observations is good, and supports our confidence.