Archived

Avalanche Forecast

Apr 7th, 2018–Apr 8th, 2018

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

Use caution around leeward alpine and treeline features as pockets of windslab may be hidden.The best quality snow can be found on shaded aspects.

Weather Forecast

A pacific frontal system is tracking inland today bringing 10-15cm of snow to the Rogers Pass area later today and overnight.Â With freezing levels reaching 1900m this could mean rain at lower elevations. Today expect overcast skies, an Alpine high of -1 deg C and Southerly winds to 20 kph. Unsettled weather is forecast for much of next week.

Snowpack Summary

A few centimeters sits on top of a sun crust on solar aspects. 15-20cm of low density powder remains on shaded aspects. Wind slabs are above treeline in lee features. 60cm of recent storm snow is settling out and appears to be bonding well on polar aspects. On solar slopes, the storm slab sits on a persistent crust.

Avalanche Summary

Thursday strong solar input contributed to a widespread natural avalanche cycle on south facing slopes. A field team directly observed a large size 2.5 Na from the Frequent Flyer path in the Connaught Creek drainage. Several large solar triggered avalanches were also observed in the highway corridor east of Rogers Pass, up to size 3.0.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Avalanche Problems

Wind Slabs

Recent shifting winds have created wind slabs above treeline. More subtle wind loaded pockets exist in lee features & can easily be triggered by skiers. Watch for these pockets around cornices, wind lips and roll overs. New snow may hide these slabs

Variable winds have created pockets of wind slab on all aspects.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1.5 - 2.5

Persistent Slabs

70-90cm of settled snow sits on the mid March crust/facet combo. This layer appears to be bonding well on polar aspects. On solar aspects, this layer fails suddenly in stability tests and has shown potential for wide propagation if triggered.

Be aware of the potential for wide propagations which could result in large avalanches.Avoid convexities or areas with a thin or variable snowpack.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3