Avalanche Forecast

Issued: Mar 1st, 2019 4:41PM

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

kdevine, Avalanche Canada

South Rockies.

Fresh storm slabs will likely be reactive to human triggering, especially in wind loaded areas, and at upper elevations. Watch for signs of instability such as whumphing, cracking and recent avalanches.

Summary

Confidence

Moderate -

Weather Forecast

FRIDAY NIGHT - Clear periods / east winds 10-15 km/h / alpine low temperature near -25SATURDAY - Mainly sunny / east winds 10 km/h / alpine high temperature near -25SUNDAY - Sunny / east winds 10-15 km/h / alpine high temperature near -20MONDAY - Sunny / northeast winds, 15-30 km/h / alpine high temperature near -15

Avalanche Summary

There were reports of numerous size 1-1.5 natural and explosives triggered avalanches on Friday.

Snowpack Summary

Up to 20 cm of new snow with moderate winds will be forming fresh storm slabs. 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 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. Recent 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

Storm Slabs

Up to 20 cm of new snow and wind will mean that storm slabs are widespread, and will likely be most reactive in wind loaded areas.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

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

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

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 2.5

Valid until: Mar 2nd, 2019 2:00PM