Archived

Avalanche Forecast

Feb 16th, 2019–Feb 17th, 2019

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.

Natural and human triggered avalanches have decreased and older persistent weak layers have become less reactive. Hazard is declining but don't be caught off guard by highly variable snow conditions.

Weather Forecast

A minor low pressure system tracking through the south of the province will bring mainly cloudy skies with isolated flurries and trace amounts of precipitation. Alpine temperatures will reach -8.0 with light north winds and the freezing level at 1000m. Frigid temperatures return Sunday with high pressure and sunshine.

Snowpack Summary

A dusting of new snow covers hard wind slabs and scoured surfaces in the alpine and exposed areas at tree line. Cold temperatures have created a weak and faceted upper snowpack. Wind slabs have been most reactive on solar aspects where crusts are buried. The Jan 17 surface hoar is down 50-70cm at TL and below.

Avalanche Summary

A natural size 2.0 was observed in the highway corridor east of Rogers Pass in Macdonald Gully #9. This avalanche appeared to be from a wind slab release in a high alpine start zone. No other avalanches were observed or reported in Glacier National Park.

Confidence

Avalanche Problems

Wind Slabs

Ongoing winds have hammered the alpine and exposed areas at tree line, making for challenging travel conditions. Slabs vary from hard and supportive to pockets of wind-loaded facets. At lower elevations slabs could propagate on buried surface hoar.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in larger avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2