Archived

Avalanche Forecast

Feb 1st, 2018–Feb 2nd, 2018

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

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: South Coast.

Friday's forecast calls for steady precipitation and rising freezing levels. This is a great recipe for avalanche activity.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

Friday: 10-25cm of new snow on Thursday night with an additional 10-15mm of precipitation on Friday / Strong westerly winds / Freezing level at 900m, climbing to 1800m by Friday afternoonSaturday: 10mm of precipitation / Light and variable winds / Freezing level at 1400mSunday: 10-20mm of precipitation / Light southwest winds / Freezing level at 2300mNote: Confidence is low for forecast wind values and precipitation amounts for Saturday and Sunday.

Avalanche Summary

No new avalanches were reported on Thursday. New precipitation and wind on Wednesday night is expected to promote a new round of storm slab activity in high elevation lee terrain, and loose wet avalanche activity on steep, lower elevation slopes.

Snowpack Summary

As of Thursday morning, between 10 and 25cm of new snow had fallen. In areas where winds were strong, new wind slabs likely exist. At treeline and below, the new snow overlies either a crust or moist snow from Monday's rain event. In high alpine areas like Sky Pilot and the Chehalis Range the new snow overlies thick storm slabs which developed during the stormy weather at the end of January.A thick crust exists up to 180cm below the surface, although a strong bond is expected at this interface.

Avalanche Problems

Storm Slabs

Rising freezing levels and steady precipitation means mixed conditions on Friday. Dense storm slabs will likely be found in high alpine wind-exposed terrain while loose wet avalanches may occur in steep terrain at treeline and below.

Avoid all avalanche terrain during periods of heavy loading from new snow and wind.Be alert to conditions that change with elevation.Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2.5

Cornices

Recent heavy snowfall and high winds have created fragile new cornice growth. These monsters may surprise with nasty consequences. Use extra caution around ridge crests.

Falling cornices may trigger avalanches on slopes below.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1.5 - 2.5