Avalanche Forecast

Issued: Mar 16th, 2018 9:26PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Loose Dry and Storm Slabs.

Conrad Janzen, Parks Canada

Little Yoho.

The new snow remains reactive to human triggering especially in the East where the up slope storm dumped the most snow. Watch the weather inputs Saturday as more than 10 cm of new snow could easily increase the danger again.

Summary

Weather Forecast

Low elevation sites on the BC side of the Rockies have not had a good freeze for a few days, and this will continue through Satruday. Up to 10cm more snow at upper elevations from an upslope storm is expected on Saturday.

Snowpack Summary

5-30 cm of new snow from the past two days has fallen with an uneven distribution in the Little Yoho region. In areas with more storm snow the soft slab is poorly bonded to the melt-freeze crusts or old snow layers below. Below this the snowpack is stable and recent tests have not found any weaknesses. Low elevation snow is becoming isothermal.

Avalanche Summary

Storm slab avalanches up to size 2 were noted today in Yoho, Loose moist, size 1 avalanches were also noted.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Problems

Loose Dry

Areas with deeper storm snow amounts are sluffing easily. This is a good time to avoid steep gullied terrain where even a small avalanche will gain mass quickly. Wind, warm temps or sunny breaks will also increase the likelihood of this problem.

Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 1.5

Storm Slabs

In places where the storm snow is deepest, a soft slab has formed that remains reactive to human triggering. Monitor the storm snow amounts frequently, and use caution on larger slopes if a storm snow slab is present.

The storm slab may be more sensitive to human triggering on solar aspects where it sits on sun crustUse caution in lee areas in the alpine and treeline. Storm snow is forming reactive slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 17th, 2018 4:00PM