Archived

Avalanche Forecast

Mar 7th, 2018–Mar 8th, 2018

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

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

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast.

Avalanche danger will increase as snow accumulates at higher elevations.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

THURSDAY: Precipitation starting Wednesday night with 5 mm by the morning and another 10-20 mm possible by Thursday afternoon. Freezing level will be steady around 1300 m so expect a mix of rain and snow at treeline elevations. Moderate south wind.FRIDAY: Flurries continue over Thursday night and into Friday bring 10-20 cm of snow by the morning, clearing in the afternoon, light wind, freezing level dropping to around 800 m.SATURDAY: Mostly sunny, light wind, freezing level rising to around 1600 m.

Avalanche Summary

No recent avalanches have been reported.A MIN report from just outside the region near Squamish on Sunday (Watersprite Lake) describes a natural size 2 avalanche that failed on a south aspect at 1750 m (see photo and details here). Sparse observations from the Squamish area over the past week suggest the snow from last week's storm may still be unsettled in that area.

Snowpack Summary

New snow will accumulate on Thursday and Friday and form extra deep deposits in wind loaded terrain. The new snow is falling on a sun crust on steep south-facing slopes, cold dry snow on polar aspects, and an overall well settled snowpack.Cornices have formed on many alpine ridgelines. They will become touchier as they grow in size, as temperatures rise, and as they are subject to the strong late-winter sun on clear days.

Avalanche Problems

Storm Slabs

Fresh storm slabs will build throughout the day at higher elevations and be most reactive on wind-loaded slopes.

Use caution above cliffs and terrain traps where small avalanches may have severe consequences.Be alert to conditions that change with elevation.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Loose Wet

Rain is possible up to treeline elevations, which could weaken the surface snow and trigger loose wet avalanches.

Use extra caution on slopes if the snow is moist or wet.Watch for terrain traps where small amounts of snow will acumulate into deep deposits.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5

Cornices

Cornices are inherently unstable, unpredictable, and demand respect. New snow and warming could make cornices extra brittle.

Give cornices a wide berth when traveling on or below ridges.Pay attention to overhead hazards like cornices.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2.5