Archived

Avalanche Forecast

Feb 1st, 2015–Feb 2nd, 2015

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

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

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

Avalanche hazard will steadily rise as snow load increases over newly buried surface hoar and crust layers.

Weather Forecast

Low pressure system will arrive to the Interior this morning bringing light to moderate amounts of snow with rising freezing levels to ~1000m. Treeline winds are forecast to stay light for most of the day and will pick up tonight. This unsettled pattern will continue for the next few days with a series of fronts that will pass through our region.

Snowpack Summary

Up to 20 cm of snow overlies the Jan 30 crust which can be found up to 2200m. Surface hoar was found on the crust and facetting has been occurring underneath it. Above 2200m firm wind pressed snow is found 20cm down. The Jan 15 surface hoar layer is down 60-90cm. The Dec 17 surface hoar/ crust complex is down 130-180cm.

Avalanche Summary

Yesterday, there was a report of a human triggered avalanche, size 1.5 at Bruins Pass into 8812 Bowl off the east ridge of 8812 Peak ~2700m, SE aspect, 15-20cm deep. Along the highway corridor there were was one loose natural avalanche size 1.5 east of the Rogers Pass summit.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Storm Slabs

~20cm of recent snow over a firm surface may be reactive to riders where wind has firmed it up enough to create a soft slab. Areas to watch for this are near ridge crests or cross loaded terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

The mid January surface hoar layer is buried 60-100cm deep. Getting this layer to fail will be difficult but triggering it from shallow areas or from heavy loads such as a cornice fall remains possible.

Pay attention to overhead hazards like cornices.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3