Archived

Avalanche Forecast

Apr 16th, 2018–Apr 17th, 2018

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

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

Regions: Banff Yoho Kootenay.

Winter conditions persist with more snow expected into Tuesday. The hazard is greatest near the divide where the most snow has fallen. Choose more conservative terrain and minimize overhead hazard until things have a chance to settle and bond.

Weather Forecast

Temperatures will remain relatively cool for the next few days, with freezing levels up to 1800m. Snowfall amounts of up to 15 cm near the divide are expected overnight and into Tuesday with a drying trend later in the day. Winds will switch to the West and increase into the moderate range on Tuesday.

Snowpack Summary

10-15 cm of new snow with light winds. Up to 40 cm of storm snow near the divide. Several buried temperature crusts exist to 2000m on all aspects and to ridge tops on solar slopes, including the Mar 15 sun crust down 35-50 cm in the alpine. Moist snow at lower elevations, with the entire snowpack becoming moist near valley bottom.

Avalanche Summary

Some sluffing in the alpine on Monday. Reports of several natural slab avalanches out of steep alpine terrain near the divide up to size 2 in the past 24 hrs. Several skier triggered storm slabs reported near the divide at treeline and above, up to size 2 in the past 48 hrs. Loose wet avalanches up to size 2 at lower elevations in the past 48hrs.

Confidence

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

Avalanche Problems

Storm Slabs

20-50 cm of storm snow has fallen over the past few days with the greater amounts near the divide, and more is expected on Tuesday. This is settling quickly but wind loaded areas and steep terrain will be suspect for the next couple days.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Persistent Slabs

While it has been several days since there have been any confirmed events directly associated with the March 15 crust, other temperature crusts have now become buried in similar locations and are providing a good sliding layer for the new storm snow.

Be cautious with convexities and steep slopes on solar aspects.The storm slab may be more sensitive to human triggering on solar aspects where it sits on a crust

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

Lower elevations may see loose wet avalanches start to occur later in the day with either temperature increases or rain as the storm finishes on Tuesday.

Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2