Avalanche Forecast

Archived

Mar 4th, 2026–Mar 5th, 2026

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Regions

Coquihalla, Harrison-Fraser, Manning, Skagit.

Stick to small slopes with limited consequences and no overhead hazard.

We have some uncertainty in the reactivity of persistent slabs, conservative terrain choices are the answer .

Confidence

Moderate

We are uncertain about forecast precipitation amounts.
We are uncertain about how quickly persistent slabs are gaining strength.

Avalanche Summary

On Sunday numerous natural avalanches were observed on east through south aspects. These avalanches were generally at treeline and failed on the late January crust. A size 2 remotely triggered, persistent slab avalanche was also reported in Allison Pass. Details here.
On Saturday, an accident occurred on Thor Peak. 3 skiers were boot packing up a couloir when they triggered a size 3 persistent slab. Another size 2 persistent slab was also remotely triggered nearby.

Snowpack Summary

20 to 40 cm of new snow is expected at upper elevations by Thursday morning, accompanied by strong west or southwest winds. Rain has saturated the top 10 to 20 cm below treeline.

This new snow overlies a melt-freeze crust on solar aspects and lower elevations, and wind-affected surfaces at higher elevations.

A persistent weak layer consisting of a crust/ facet layer from late January is currently buried 40 to 80 cm deep across the region. This layer has been reactive in recent days.

The snowpack below is strong and well-bonded.

Weather Summary

Wednesday Night
Cloudy. 1 to 15 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level 1300 m.

Thursday
Mostly cloudy. 1 to 2 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -6 °C.

Friday
Cloudy. 10 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -4 °C.

Saturday
Mostly cloudy. 5 to 15 cm of snow at treeline, rain below. 70 km/h west ridgetop wind. Treeline temperature -1 °C. Freezing level 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for large avalanches due to buried weak layers.
Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.
Use conservative route selection and resist venturing into complex terrain.
Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.