Archived

Avalanche Forecast

Mar 22nd, 2018–Mar 23rd, 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

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

Regions: Lizard-Flathead.

Storm slabs will likely be reactive to skier and rider triggers. Changing winds from the East to the Southwest will potentially form wind slabs on most aspects.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Overnight Thursday: New snow 5-10 cm accompanied by strong southwest winds and freezing level at valley bottom.Friday: Cloudy with sunny periods. Snow 2-10 cm possible, but low confidence with actuals. Ridgetop winds light gusting strong from the southwest. Alpine temperatures near -2 and freezing levels 1500 m.Saturday: Mix of sun and cloud. Snow amounts near 5 cm and ridgetop wind strong from the southwest. Alpine temperatures near -3 and freezing levels 1500 m.Sunday: Mix of sun and cloud. Freezing levels near 1300 m. Ridgetop winds mostly light with strong gusts from the southwest.

Avalanche Summary

No recent avalanches reported on Thursday. 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

Up to 10 cm of new snow will likely have a poor bond to the plethora of old snow surfaces including a melt-freeze crust on sunny aspects, surface hoar on north aspects above 1600 m and moist snow surfaces below 1600 m. Isolated wind slabs are building on most aspects due to the changing winds and overhanging cornices exist along ridgelines. 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 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.

Use caution in lee areas in the alpine and tree line, especially on NE-E facing slopes.Avoid large slopes and convex features.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Loose Wet

Loose wet avalanches may occur below treeline due to higher freezing levels and rain.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 1.5