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 Loose Wet, Persistent Slabs and Storm Slabs.

MM, Avalanche Canada

Glacier.

The strong spring sunshine and rapidly warming temperatures will increase the the avalanche danger throughout the day. Natural avalanches are likely and these have the potential to step down to the Feb 3rd crust/facet combo.

Summary

Confidence

Moderate

Avalanche Summary

A field team in the Bonney area Wednesday observed several loose snow avalanches up to size 2.5, from the steep solar slopes of Ross Peak and Mt. Green.

Early this week, wind spikes triggered numerous avalanches up to sz 3.

On Monday, just north of the park, a group of skiers remotely triggered a size 3 on the Feb 3 crust.

Last Thursday, we observed multiple naturally-triggered size 3 slab avalanches, likely failing on the Feb 3rd crust.

Snowpack Summary

A surface crust caps 30-40cm of recent storm snow that has been transported by strong Southwest winds. This new snow rests on a variety old surfaces, most importantly a thin sun crust on South & West aspects.

80-140cm of settled snow sits atop a sugary facet layer. These facets are not bonding well to the widespread, very firm crust from Feb 3rd. This crust is a significant persistent weak layer and will be a layer of concern for the foreseeable future.

Weather Summary

Today marks the beginning of a warm up across the interior with freezing levels forecasted to 3300m.

Tonight: Alpine low -5Â°C. Freezing level (FZL) 1400m. Light W ridgetop winds.

Fri: Mainly cloudy. Alpine high 3Â°C, FZL 2900m. Light W winds.

Sat: Sun/cloud. Low 3Â°C, High 7Â°C. Light S winds. FZL 3300m

Sun: Sun/cloud. Low 3Â°C, High 7Â°C. FZL 3300m. SW winds 10-20km/hr.

Terrain and Travel Advice

Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
Avoid exposure to steep sun exposed slopes.
A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Loose Wet

With sunshine and rising freezing levels in the forecast, avalanche activity is expected to increase on solar aspects. Minimize your exposure to Southerly slopes, especially during the warmest part of the day.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

This crust-facet combo (Feb 3rd) was created by a rain event followed by an extended cold, clear period without snow earlier this month. 80-140cm now sits on the persistent weak layer. Human-triggered avalanches on this layer remain possible, and resulting avalanches could be very large in size.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Storm Slabs

Storm snow was accompanied by gusty SW winds. This built reactive soft slabs in lee areas. If triggered, these slabs may provide enough mass to trigger the deeper Persistent Weak Layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

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