Avalanche Forecast

Issued: Apr 8th, 2019 4:54PM

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

ghelgeson, Avalanche Canada

Lizard-Flathead.

We're entering a bit of a stormy period for the next few days. The precipitation amounts are pretty modest, but the series of weak disturbances may build shallow storm slabs in high elevation terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

We're entering a bit of a stormy period for the next few days. The precipitation amounts are pretty modest, but the series of weak disturbances could offer a nice refresh at upper elevations.MONDAY NIGHT: Freezing level around 2000 m, light variable wind, 1 to 5 cm of snow possible at upper elevations.TUESDAY: Overcast, freezing level around 1800 m, light southerly wind, 5 to 10 cm of snow possible at upper elevations, an additional 4 to 8 cm of snow possible Tuesday night.WEDNESDAY: Broken cloud cover, freezing level around 2000 m, light southerly wind, 1 to 5 cm of snow possible at upper elevations.THURSDAY: Scattered cloud cover, freezing level around 1800 m, light to moderate southwest wind, trace of snow possible at upper elevations.

Avalanche Summary

On Monday there was a natural loose wet avalanche cycle to size 1.5 on solar aspects as the new snow ran on the crust. On Sunday storm slabs to size 1.5 were susceptible to explosive control work to size 1.5 on north and northeast facing terrain between 1900 and 2000 m. Numerous loose avalanches to size 1.5 were reported from terrain that generally faces north around 2000 m on Saturday. A natural cornice failure also produced a size 2 slab on a northeast facing slope at 2200 m on Saturday.

Snowpack Summary

Sunday night the region picked up 10 cm of moist snow. This snow rests on a supportive crust above about 1400 m. Below 1400 m the snowpack is becoming isothermal. During the heat of the day, especially under direct sun, the snow surface becomes moist or wet almost everywhere. The exception being high elevation north facing features. With spring conditions, the avalanche hazard will fluctuate greatly depending on the strength of the overnight re-freeze and how quickly the snowpack is warmed up.Steep, north facing, alpine terrain may still hold a cold, dry, snowpack where a well settled slab rests on weak facets (sugary snow). Although unlikely, human triggering of persistent slabs on this layer may still be possible, especially in rocky alpine terrain with a shallow or highly variable depth snowpack.

Problems

Loose Wet

The likelihood of loose avalanches increases as temperatures warm through the day and/or if the sun comes out for a prolonged period of time. Loose wet avalanches are more likely in areas with fresh snow.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.Loose avalanches may start small but they can grow and push you into dangerous terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Storm Slabs

Watch for shallow storm slabs to form in alpine terrain if the region receives more than 10 cm Tuesday.

Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.Be alert to conditions that change throughout the day.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 9th, 2019 2:00PM