Avalanche Forecast

Issued: Mar 26th, 2017 3:45PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Cornices.

cgarritty, Avalanche Canada

South Coast Inland.

As you travel, keep in mind that avalanche problems will increase with elevation. Fortunately, the current problems aren't difficult to manage with thoughtful terrain analysis and selection.

Summary

Confidence

High -

Weather Forecast

Monday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Freezing level to 1700 metres with alpine temperatures around -2.Tuesday: Cloudy with scattered flurries and a trace of new snow to the north of the region. 5-20 cm in the south. Moderate to strong southwest winds. Freezing level to 1700 metres with alpine temperatures around -2.Wednesday: Periods of snow bringing 15-20 cm of new snow to the south of the region, scattered flurries and 5 cm in the north. Light to moderate south winds. Freezing level to 1700 metres with alpine temperatures around -2.

Avalanche Summary

Reports from Friday and Saturday showed wind slabs releasing to Size 1 with ski cutting in steep lee and crossloaded features as well as loose moist sluffs triggering naturally to Size 1 out of steep terrain. Saturday's observations showed a marked reduction in wind slab reactivity in the north of the region.Reports from Thursday showed both natural and skier triggered storm and wind slabs releasing from Size 1-2 in the north of the region. Wind slabs were noted releasing above the melt freeze crust that was buried on March 22. In northern parts of the region, the deeper February weak layers continue to present a low probability / high consequence avalanche danger scenario.

Snowpack Summary

Steady light snowfalls over last week deposited 25-45 cm of heavily wind affected new snow to the region. Periodic rises in freezing levels to 2000 metres or higher over the same time period have been setting up a series of crust layers (March 20, 22, 23) within the upper snowpack at lower elevations and on solar aspects. A more widespread thick rain crust (March 15) exists up to 2100m and is now buried approximately 45-70cm below the surface. In the north of the region, the February weak layers are 100-140 cm deep and include a buried surface hoar layer as well as a crust/facet layer that appear to be gaining strength. In the southern parts of the region, the mid and lower snowpack are generally well settled and strong.

Problems

Wind Slabs

Light new snow amounts combined with moderate to strong southeast to southwest winds have been building wind slabs. Expect the greatest reactivity in the immediate lee of exposed terrain features and be aware of the potential for cornice triggers.

Be alert to conditions that change with elevation.Be increasingly cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Recent warm and windy weather has been promoting cornice growth. While they are a hazard in themselves, the danger increases with the potential for a cornice fall to trigger a wind slab sitting below it.

Pay attention to overhead hazards like cornices.Even small cornice falls may trigger larger avalanches.Cornices become weak with daytime heating or solar exposure.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 27th, 2017 2:00PM