Archived

Avalanche Forecast

Mar 14th, 2019–Mar 15th, 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

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

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: South Columbia.

The recent storm snow has been most reactive to human triggers on solar aspects where the new snow is sitting on crust and/or in wind effected terrain.

Confidence

High -

Weather Forecast

THURSDAY NIGHT: Cloudy with isolated flurries; trace of new snow / Light to moderate, westerly winds / Alpine low -8 / Freezing level below valley bottom.FRIDAY: Mix of sun and cloud / Light, westerly winds / Alpine high 2 / Freezing level 1500 m.SATURDAY: Sunny / Light, westerly winds / Alpine high 4 / Freezing level 1800 m.SUNDAY: Sunny / Light, westerly winds / Alpine high 6 / Freezing level 2200 m.

Avalanche Summary

On Wednesday, numerous natural storm slab avalanches up to size 3 and rider triggered up to size 2 were reported on primarily solar aspects at treeline and above. Some of the avalanches were triggered remotely from lower angle terrain by skiers 50 m. away from the slope that avalanched. This suggests that recent storm snow is still very sensitive to human triggers in specific locations.

Snowpack Summary

30-60 cm of recent storm snow is sitting mainly on facets (sugary snow), as well as surface hoar (feathery crystals) in sheltered areas and a crust on sun exposed slopes. There are two weak layers of surface hoar in the upper snowpack that were buried in late January and early February. They can be found between 60-120 cm below the surface. These layers consist primarily of surface hoar, though they may be associated with crusts on steeper, south facing slopes. These weak layers are most prominent on south facing slopes and all aspects below treeline. Avalanche activity on these layers has declined in recent days, however it may still be possible to trigger an avalanche in isolated areas such as steep cutblocks, large open glades, and steep south facing terrain.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where the cold temperatures continue to facet (weaken) the snowpack.

Avalanche Problems

Storm Slabs

The recent storm snow has been most reactive on solar aspects where the new snow sits on crust and/ or in wind effected terrain.

Avoid steep terrain where the snow feels stiff or slabby.Use extra caution on solar aspects where the new snow is sitting on a crust.Reduce exposure to over-head hazards such a large cornices during periods of strong solar radiation.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2