Archived

Avalanche Forecast

Apr 12th, 2018–Apr 13th, 2018

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

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

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

Regions: Northwest Inland.

New snow and wind have formed small wind slabs on lee features below ridgetops.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

FRIDAY: Cloudy with flurries. Strong southerly ridgetop winds. Freezing level around 1000 m.SATURDAY: Mix of sun and cloud. Moderate southwesterly ridgetop winds. Freezing level around 1100 m.SUNDAY: Mostly cloudy. Light northeasterly ridgetop winds. Freezing level rising to around 1300 m.

Avalanche Summary

On Wednesday, a size 2 wind slab and a 2.5 deep persistent slab both on west aspects between 1000-1300 m were triggered by explosives near Ningunsaw.

Snowpack Summary

5-10 cm of new snow and strong southeasterly winds have formed fresh wind slabs on lee features at treeline and above.Weak layers buried around March 19th are roughly 40 cm below the surface (up to 100 cm in deeper snowpack areas). These weak layers include surface hoar on shaded aspects at high elevations and hard crust layers on solar aspects and below treeline.Near the bottom of the snowpack, weak and sugary facets are found in shallow, rocky snowpack areas. Storm slabs have stepped down to these facets and producing very large avalanches in northern parts of the region.

Avalanche Problems

Wind Slabs

New snow and strong winds will form thin slabs in leeward areas near ridge crests and convex features. These slabs may be touchy were they sit on a recent crust.

Avoid shallow, rocky areas where the snowpack transition from thin to thick.Avoid areas that look freshly loaded with snow; especially convex features below ridgetops.Use caution when transitioning into wind effected terrain.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5

Loose Wet

Sun and daytime warming are factors to keep in mind. Watch for wet snow on sunny aspects and lower elevation slopes.

Avoid steep terrain that is in the sunshine.Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2