Archived

Avalanche Forecast

Mar 22nd, 2025–Mar 23rd, 2025

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Little Yoho.

The persistent slab problem is less of a concern in this subregion but the amount of serious avalanche activity in adjacent areas has been alarming.

Field observations remain limited, particularly in the alpine. Do not make assumptions. Confirm the snowpack is favorable before committing to serious terrain.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed in Little Yoho Saturday.

On Wednesday, avalanche control on Mount Field and Dennis produced avalanches to size 2.5 on the persistent layer.

Over the past two weeks, many large avalanches have been seen in adjacent areas to the east of the divide. See the BYK bulletin for details.

Snowpack Summary

Expect surface crusts on solar aspects at treeline and below.

At treeline, 70-100 cm of snow overlies the Jan. 30 / Feb. 22 drought layers, which consist of 20-30 cm of weak faceted crystals. These layers have been reactive in tests and recent avalanches in adjacent areas.

In this thicker, western, snowpack region, the facet/depth hoar basal layer is less prominent than it is east of the divide but likely exists in thin areas.

Average snowpack depth at treeline is ~200 cm.

Weather Summary

Trace amounts of snow will accumulate overnight Saturday as west winds increase to moderate in the alpine. Treeline temperatures drop to near -10C.

Sunday, flurries continue as winds increase to the strong range and the freezing level approaches 1900m.

Watch for rising freezing levels into the week.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Be careful as you transition into wind-affected terrain.

Avalanche Problems

Persistent Slabs

A 60-100 cm slab overlies mid-pack facets. Caution is advised: avoid start zones and be very wary of overhead hazard.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3.5

Wind Slabs

South and west winds over the last few days have led to the development of wind effect and small thin slabs at treeline and above. If initiated, these slabs may be enough to activate the persistent slab.

Light snow and increased winds through Monday will contribute to these slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 1.5