Avalanche Forecast

Issued: Apr 22nd, 2018 4:32PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Cornices and Loose Wet.

jsmith, Avalanche Canada

South Rockies.

Sunshine and soaring freezing levels throughout the week will elevate the avalanche danger. Cornices are BIG and when they fail there is the potential to trigger large avalanches on deeply buried weak layers.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

MONDAY: Sunny. Light east wind. Alpine temperature +2. Freezing level rising to 2500 m.TUESDAY: Sunny. Light to moderate southwest wind. Alpine temperature +4. Freezing level rapidly rising to 3200 m.WEDNESDAY: Sunny. Light west wind. Alpine temperature +3. Freezing level 3000 m.

Avalanche Summary

No new avalanches were reported in this region. Avalanche reports have been limited due to very few information sources this time of year. If you have been out, please post your observations on the Mountain Information Network (MIN).

Snowpack Summary

Cornices are large and when they fail there is the potential to trigger large avalanches on deeply buried weak layers. Lingering small wind slabs may still be reactive to human triggers on leeward slopes below ridgetops. Below the surface there are numerous crusts in the upper 100 cm of the snowpack. A well settled and moist mid-pack sits above sugary facets in many parts of the region, especially thin snowpack areas.

Problems

Cornices

Sunshine and warming temperatures will increase the likelihood of cornice fall.

Cornices become weak with daytime heating. Give them a wide berth both from above and below.Falling cornices may trigger persistent weak layers deeper in the snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Loose Wet

When the sun comes out it will quickly weaken the new snow and cause loose wet avalanches on steep solar slopes.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 23rd, 2018 2:00PM