Avalanche Forecast

Issued: Apr 11th, 2018 4:42PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Loose Wet.

jsmith, Avalanche Canada

Northwest Inland.

Forecast new snow and wind Wednesday night are expected to create fresh wind slabs reactive to human triggers.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TONIGHT: 5-10 cm new snow. Light southwesterly ridgetop winds. Freezing level around 500 m.THURSDAY: Mix of sun and cloud with isolated flurries. Light southwesterly ridgetop winds. Freezing level around 1000 m.FRIDAY: Mostly cloudy with flurries. Strong southerly ridgetop winds. Freezing level around 1000 m.SATURDAY: Mostly cloudy with flurries. Moderate southwesterly ridgetop winds. Freezing level around 1200 m.

Avalanche Summary

Numerous natural loose wet avalanches up to size 2 were reported on Tuesday.

Snowpack Summary

Rising freezing levels and daytime warming have created moist or wet snow surfaces on all but alpine, northerly aspects where 20 cm up to 50 cm of recent storm snow has been redistributed by strong winds. 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.

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.

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

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.

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

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 12th, 2018 2:00PM