Archived

Avalanche Forecast

Apr 11th, 2017–Apr 12th, 2017

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

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

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

Regions: Glacier.

Periods of intense solar are possible today, and the sun has PUNCH! If the sun does show itself, avoid exposure to steep solar aspects and exposure to slopes threatened by cornices.

Weather Forecast

Today will be unsettled and convective. Expect a mix of sun, cloud and flurries with freezing levels around 1600m and generally light winds. On Wed a low pressure system will move in later in the day, bringing up to 10cm. Freezing levels should be around 1900m with gusty winds. Thurs will be similar, with another 5-10cm.

Snowpack Summary

At treeline and above over 45cm of snow has fallen in the last 5 days, amounts decrease with elevation. The new snow is settling and overlies a firm crust everywhere except high elevation N'ly aspects. Strong S'ly winds loaded lee features over the weekend. Cool temps overnight are providing crust recoveries, stabilizing lower elevations.

Avalanche Summary

Strong solar yesterday morning triggered loose, moist avalanches to size one. These loose avalanches triggered a few size 2 slabs, running on the crust down ~45cm. In addition a few large cornice failure were observed from N'ly aspects, but they did not step down and trigger deeper layers. Small, thin windslabs have been reported in the alpine.

Confidence

Timing or intensity of solar radiation is uncertain

Avalanche Problems

Storm Slabs

In most areas the storm slab overlies a crust, which provides a good sliding layer if the slab is triggered. On lee features that have been windloaded, deeper pockets may be more reactive to human triggering.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Cornices

HUGE cornices guard the high alpine ridges and they keep growing. If they fail due to direct sun, human loading, or wind loading, they could trigger deep persistent slabs. Even if they don't, that bus sized chunk trundling down is concern in itself.

Minimize exposure to overhead hazard from cornices.Stay well to the windward side of corniced ridges.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4