Avalanche Forecast

Issued: Mar 2nd, 2019 4:51PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs and Persistent Slabs.

shorton, Avalanche Canada

South Rockies.

Cold dry conditions continue. Watch for signs of instability such as whumpfing, cracking, and recent avalanches.

Summary

Confidence

Moderate - Wind speed and direction is uncertain

Weather Forecast

SUNDAY NIGHT: Clear, light northeast wind, alpine temperatures drop to -28 C.SUNDAY: Sunny, light northeast wind, alpine high temperature near -20 C.MONDAY: Sunny, light northeast wind, alpine high temperature near -13 C.TUESDAY: Sunny with cloudy periods, light southeast wind, alpine high temperatures near -10 C.

Avalanche Summary

A few small wind slab avalanches (size 1) were triggered by skiers on Saturday. On Friday, several small slabs were triggered by humans and explosives (10-30 cm thick). Some small natural wind slab avalanches were also observed.

Snowpack Summary

10-20 cm of recent snow with moderate winds has likely formed wind slabs in exposed terrain. Older wind slabs will be buried under the new snow and may be difficult to detect.A weak layer of facets (sugary snow) and surface hoar (feathery crystals) that was buried in mid-January is down approximately 40-80 cm. This layer is most prominent in the Elk Valley between 1600 m and 1900 m, but it has been found up to 2200 m in some areas. This weak layer may exist in combination with a crust on south-facing slopes. Snowpack tests and avalanche reports suggest that this layer remains reactive to human triggers.The bottom half of the snowpack is composed of weak, sugary facets.

Problems

Wind Slabs

Up to 20 cm of new snow and wind has formed wind slabs that may be reactive to human triggering at upper elevations.

Use caution in freshly wind-loaded features, especially near ridge crests and in steep terrain.If triggered, wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

A weak layer of surface hoar is buried 40 to 80 cm deep, and is most prominent between 1600 and 1900 m.

Use added caution in open terrain features such as cutblocks, gullies and cutbanks.Be aware of the potential for wide propagation.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 2.5

Valid until: Mar 3rd, 2019 2:00PM