Archived

Avalanche Forecast

Feb 21st, 2019–Feb 22nd, 2019

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

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

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Inland.

New slabs will likely form during Thursday night's storm. Expect to find the deepest and touchiest deposits in cross-loaded and lee terrain features.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

THURSDAY NIGHT: Cloudy with snowfall, accumulation 5 to 10 cm, strong southwest wind, alpine temperature -8 C.FRIDAY: Cloudy with snowfall, accumulation 1 to 5 cm, light to moderate southwest wind, alpine temperature -8 C.SATURDAY: Early-morning snowfall and clearing over the day, accumulation 1 to 3 cm, light east wind, alpine temperature -16 C.SUNDAY: Clear skies, light to moderate east wind, alpine temperature -16 C.

Avalanche Summary

A few small wind slab avalanches were triggered by skiers and naturally on Wednesday. They were on all aspects, in steep terrain, and at treeline and alpine elevations. The slabs were generally 10 to 20 cm deep.

Snowpack Summary

Thursday night into Friday's storm is expected to deliver another 10 to 15 cm of snow, which will add to the 5 to 10 cm received on Tuesday. Strong southwest wind during both of these storms will form wind slabs in cross-loaded and lee terrain features in exposed areas. In sheltered areas at and below treeline, this new snow fell onto pockets of feathery surface hoar crystals and soft, faceted snow.In the south of the region, the remainder of the snowpack is well-settled. In the north of the region, around 50 cm of snow may overly a weak layer of surface hoar or faceted grains.

Avalanche Problems

Wind Slabs

More snow Thursday night will produce fresh wind slabs in exposed areas. The touchiest deposits will likely be in lee and cross-loaded terrain, as the snow will fall with strong southwest wind. The slabs may not bond well to underlying faceted snow.

New snow may require several days to settle and stabilize, as it overlies weak faceted snow.Be careful around wind loaded pockets near ridge crests and roll-overs.Watch for patterns of wind loading as you venture into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2