Archived

Avalanche Forecast

Mar 21st, 2018–Mar 22nd, 2018

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

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: Lizard-Flathead.

Storm slabs will likely build throughout the day. A MODERATE hazard may be the story in the am, but strong easterly winds and new snow is driving the danger to CONSIDERABLE in the alpine for the afternoon.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

Thursday: 10-20 mm expected and accompanied by strong easterly winds. Alpine temperatures near plus 1 with freezing levels 1800 m. Friday: Mainly cloudy with up to 10 cm of new snow. Alpine temperatures near -2 and freezing levels dropping to 1300 m. Ridgetop winds light with strong gusts from the southwest.Saturday: Mainly cloudy with 5 cm of new snow. Alpine temperatures near -3 and freezing levels 1300 m. Ridgetop winds light from the southwest.

Avalanche Summary

On Wednesday, several natural loose wet releases from sunny aspects and loose dry from northerly aspects were reported up to size 1. The avalanche hazard will rise with forecast wind and precipitation.

Snowpack Summary

Forecast new snow will likely have a poor bond to the plethora of old snow surfaces including a melt-freeze crust on sunny aspects, or surface hoar on north aspects above 1500 m. Isolated wind slabs just below ridgetop exist on northeasterly aspects and moist snow surfaces are found below 1500 m. 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 are currently dormant.

Avalanche Problems

Storm Slabs

The new storm snow may not bond well to the plethora of underlying surfaces, especially where it sits on a slippery melt-freeze crust or surface hoar on northerly aspects in upper elevations.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.Avoid large slopes and convex features.Use caution in lee areas in the alpine and tree line, especially south / west facing slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 2

Loose Wet

Loose wet avalanches may occur at lower elevations due to rain and rising freezing levels. Watch for moist or wet snow and natural avalanches.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5