Archived

Avalanche Forecast

Jan 28th, 2019–Jan 29th, 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

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

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: Lizard-Flathead.

Storm snow from last week has been redistributed into pockets of wind slab at treeline and in the alpine. These are likely becoming less reactive, but will still need careful management in wind loaded terrain.

Confidence

Moderate - The weather pattern is stable

Weather Forecast

MONDAY NIGHT - Clear periods / light southwest winds / alpine low temperature near -10TUESDAY - Mainly sunny with cloudy periods / southwest winds 10-30 km/h / alpine high temperature near -7WEDNESDAY - A mix of sun and cloud / southwest winds 10-30 km/h / alpine high temperature near -7 THURSDAY - Cloudy with sunny periods / southwest winds, 20-30 km/h / alpine high temperature near -4

Avalanche Summary

No new avalanches were reported on Sunday.On Saturday, a size 1 human triggered avalanche was reported on a northeast aspect around treeline. On Friday, a human triggered size 1 avalanche was reported on a northeast aspect at 1900 m. This avalanche reportedly occurred on the surface hoar layer that is buried 10-30 cm.

Snowpack Summary

About 5 cm of new snow likely sits on a a crust below 1500 m, and on sun-exposed slopes at all elevations. Sun-exposed slopes may become moist during the day.15-35 cm of snow is sitting on a weak layer of surface hoar (feathery crystals), which is most prominent around treeline. On sun-exposed slopes, the surface hoar may be sitting on a sun crust, and below treeline it may be sitting on a melt-freeze crust on all aspects.In shallow snowpack areas, the base of the snowpack is composed of facets (sugary snow). In deeper snowpack areas, the middle and lower portions of the snowpack appear to be generally strong.

Avalanche Problems

Persistent Slabs

A weak layer of surface hoar (feathery crystals) and sun crust (on solar aspects) is buried under 15-35 cm recent snow. Deposits are likely deeper and more reactive in wind-loaded areas.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Watch for signs of instability such as whumpfing, or cracking.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2