Archived

Avalanche Forecast

Apr 22nd, 2023–Apr 23rd, 2023

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

Below Threshold

The avalanche danger rating below treeline will be below threshold

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

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Little Yoho.

A low pressure system will affect the region Sunday and Monday and may lead to an uptick in the avalanche hazard.

Watch for instabilities in the recent snow, particularly as it sits over buried crusts.

Confidence

Moderate

Avalanche Summary

A skier triggered a sz 2 slab on a steep N aspect in the alpine near Emerald Lake on Saturday and others reported touchy moist snow above the temperature crusts on Friday.

Snowpack Summary

Almost daily accumulations of new snow are competing with new sun crust formation on solar aspects with multiple buried crusts present in the upper snowpack. On northerly aspects, up to 40cm of recent snow remains preserved with buried temperature crusts as high 2200m. The basal snowpack remains weak in shallow locations with facets and depth hoar.

Weather Summary

A cold front approaches the region Sunday afternoon. 2-5mm of rain below 1900mm with freezing levels rising to 2000- 2200m. Winds will increase to 30 to 40km/hr SW.

Overnight freezing levels only drop to around 1700m with overcast skies as winds will decrease to 20-30km/h. This will lead to less crust recovery than has been seen for several days.

Terrain and Travel Advice

Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
Cornice failures could trigger very large and destructive avalanches.
Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Avalanche Problems

Storm Slabs

5cm can be expected to fall as snow in the alpine and upper treeline into Monday with SW winds. Pay attention to recent accumulations that overlie crusts. Local slab formation will vary greatly with temperature and wind effects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 1.5

Loose Wet

With freezing levels rising and small amounts of rain forecast, expect heating to create moist snow at lower elevations. As this affects snow that has accumulated over crusts it may fail naturally in very steep terrain and with skier traffic in steep terrain.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2