Archived

Avalanche Forecast

Apr 5th, 2016–Apr 6th, 2016

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

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

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

Surface slabs from yesterday's storm overlie a warm, Spring snowpack. Last night was the first decent freeze at tree-line in several days.

Weather Forecast

Mainly cloudy today with flurries, freezing levels staying around 1800m, and light to gusting moderate SW winds. More of the same tomorrow, with 5-10cm of snow in total from Tuesday morning to Wednesday night. Things will change dramatically on Thursday, with freezing levels rocketing to 3600m, sunshine, and light winds.

Snowpack Summary

Up to 15cm of snow fell overnight at 1900m. The new snow is insulating a moist snowpack and likely formed new storm slabs in immediate lee areas. The rain at lower elevations prevented a solid crust recovery and the snowpack is isothermal. Multiple crusts in the top meter of the snowpack provide sliding surfaces, especially on solar aspects.

Avalanche Summary

The parade of moist and wet avalanches continued yesterday with the rain. Numerous moist and wet avalanches, both loose and slab, were observed throughout the highway corridor. These slides are pushing very heavy, dense debris and are digging down to ground by the time they reach the valley. A moist size 3 was observed from Perley Rock yesterday.

Confidence

Avalanche Problems

Storm Slabs

Storms slabs will have formed overnight with the new snow and winds. Given the warm temp's, they will be stubborn to trigger, but be looking for them as you head onto the lee side of ridges.

Be cautious as you transition into wind affected terrain.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

Lower elevation tests show an isothermal snowpack. While temp's have dropped overnight, brief glimpses of a strong April sun can be enough to trigger loose avalanches. These loose slides have the potential to entrain a lot of mass and be destructive.

Use extra caution on solar slopes or if the snow is moist or wet.Be alert to conditions that change with elevation.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

Step-down avalanche potential exists with the many crusts buried in the upper metre. Tests on these crusts indicate that it will likely take a heavy load to trigger them, like a cornice fall or another avalanche. Expect large avalanches if they move!

Use extra caution on slopes if the snow is moist or wet.Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4