Archived

Avalanche Forecast

Mar 20th, 2018–Mar 21st, 2018

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Lizard-Flathead.

Wind slabs at upper elevations may be reactive to human triggers, especially on leeward slopes or behind terrain features. Avoid solar slopes if the sun comes out.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Wednesday: Mix of sun and cloud. Alpine high near plus 3 and freezing levels rising to 1900m. Ridgetop winds light from the South. Snow expected overnight 10-20 cm. Thursday: Periods of snow 10-20 cm with heavier amounts expected later in the day above 1300 m. Alpine high near plus 2. Ridgetop winds strong from the East. Friday: Cloudy with possible sunny breaks. Alpine temperatures near -1. Light-moderate precipitation amounts. Ridgetop winds moderate to gusty from the southwest.

Avalanche Summary

On Monday we received reports of several natural size 1.5 dry loose avalanches, and confined to the recent storm snow. No new avalanche reports submitted on Tuesday.

Snowpack Summary

Up to 12 cm of new snow fell on Monday. This new may have a poor bond to a wide variety of old snow surfaces including a melt-freeze crust on sunny aspects, or surface hoar (up to 30mm in size) and/or dry snow on north aspects above 1500-1800m.Deeper in the snowpack, the mid-December and late-November weak layers are composed of crusts and sugary facets, which are down 150-300 cm. These layers have been dormant but may be awoken by a large trigger, such as a cornice fall, or by humans traveling in thin-to-thick snowpack areas.

Avalanche Problems

Wind Slabs

The recent snow may not bond well to underlying surfaces, especially on leeward slopes that are loaded. Dry loose sluffs may run fast and far, especially if the new snow sits on a slippery melt-freeze crust.

Use caution in lee areas in the alpine and tree line.Keep an eye out for localized areas of deeper snow accumulation, and pockets of wind slab.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

If the sun comes out on Wednesday, expect the new snow to become reactive and slide naturally.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2