Archived

Avalanche Forecast

Apr 5th, 2018–Apr 6th, 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

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

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Lizard-Flathead.

Watch for wind slabs in open areas at treeline and above. And, be mindful of cornices along ridgelines, a cornice failure could trigger slabs on the slopes below.

Confidence

Moderate - Freezing levels are uncertain on Sunday

Weather Forecast

TONIGHT: Flurries. Accumulation 3-6 cm. Ridge wind moderate, northeast. Alpine temperature near -15. Freezing level valley bottom.FRIDAY: Sunny with cloudy periods. Ridge wind light, southwest. Alpine temperature near -5. Freezing level 1000 m.SATURDAY: Cloudy, flurries. Accumulation 5-15 cm. Ridge wind light to moderate, south. Alpine temperature near 0. Freezing level 1000 m.SUNDAY: Cloudy, flurries. Accumulation 2-8 cm. Ridge wind strong, southwest. Temperature near 0. Freezing level 1800 m.

Avalanche Summary

Numerous small slab avalanches have been reported in the top 10-20 cm of snow all through this week. It appears as though moderate amounts of new snow with just the right amount of wind have continuously set up thin, but touchy wind slabs in a variety of places. While these have been mostly small (size 1), a size 2 wind slab avalanche was reported near Fernie on Wednesday morning on a northeast aspect at approximately 2000 m.Also, cornices are large along ridgetops and were actively failing last week.

Snowpack Summary

20-30 cm storm snow sits above a variety of crusts on all but high north aspects. Wind has formed isolated slabs in lee features, and in some cases snow may be poorly bonded to the crusts.There are some reports of a surface hoar layer roughly 80 cm deep on north aspects at treeline, but no recent avalanche activity on this layer. A layer of sugary facets around a crust exists near the bottom of the snowpack, but this layer has been inactive for some time.

Avalanche Problems

Wind Slabs

Wind slabs have been a consistent feature for several days and will continue to be an issue in exposed terrain. Shifting winds means you should look out for wind slab on almost all aspects.

Pay attention to overhead hazards like cornices which could easily trigger slabs.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Cornices

Cornices are reported to be large and several cornice failures have recently been noted.

Give cornices a wide berth when travelling on or below ridges.Extra caution needed around cornices with current conditions.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1.5 - 2.5