Archived

Avalanche Forecast

Feb 20th, 2019–Feb 21st, 2019

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

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

Regions: Northwest Inland.

Wind slabs exist at higher elevations from recent snow and strong wind. The next storm will approach Thursday afternoon.

Confidence

High -

Weather Forecast

WEDNESDAY NIGHT: Mostly cloudy, light northwest wind, alpine temperature -9 C.THURSDAY: Cloudy with light snowfall, accumulation 1 to 3 cm, light to moderate west wind, alpine temperature -8 C.FRIDAY: Cloudy with snowfall, accumulation 5 to 10 cm, moderate to strong southwest wind, alpine temperature -7 C.SATURDAY: Early-morning snowfall and clearing over the day, accumulation 1 to 3 cm, light east wind, alpine temperature -16 C.

Avalanche Summary

Small wind slab avalanches were triggered naturally and by skiers on Tuesday. They were on all aspects and at treeline and alpine elevations. The slabs ranged from 20 to 60 cm deep.

Snowpack Summary

Thursday and Friday's storm may 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

Wind slabs have formed in exposed terrain from recent snow and strong wind. The slabs may not bond well to underlying faceted snow. The slabs may grow as the next storm approaches on Thursday.

Be careful around wind loaded pockets near ridge crests and roll-overs.New snow may require several days to settle and stabilize, as it overlies weak faceted snow.Fresh wind slabs may form in the afternoon as the next storm rolls in.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2