Avalanche Forecast

Issued: Jan 14th, 2018 4:00PM

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

snow safety, Parks Canada

Little Yoho.

This is a good time to be conservative in your terrain choices and minimize exposure to avalanche terrain. The chances of human triggered avalanches will increase as temperatures rise.

Summary

Weather Forecast

A temperature inversion will continue through the forecast region, with alpine temperatures above freezing through Monday into Tuesday. Skies will remain relatively clear and winds light. Expect unusually strong solar outputs for this time of the year on South and West aspects Monday and Tuesday afternoon.

Snowpack Summary

Warm alpine temperatures have moisten the upper snowpack on steep solar aspects. There is 40-65 cm over the Dec.15 persistent weak layer of surface hoar at treeline. This is becoming reactive to skiers and producing easy to moderate test results as shown in this video from Mt Field. Below this is a faceted but generally supportive snow pack.

Avalanche Summary

Snowballing observed around rock features on steep solar aspects Sunday afternoon. No new avalanche activity observed. A field team Saturday traveling up Mt Field noticed lots of whumphing and cracking in open glades at treeline, this activity was failing on the Dec.15 persistent weak layer.

Confidence

Problems

Persistent Slabs

There is a widespread weak layer of surface hoar from Dec 15th down 40-60 cm with a stiff enough slab over it to start producing avalanches. Be very careful and travel conservatively even if you observe no avalanches.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Watch for the changing feel of the snow under your feet and be wary of areas with denser surface snow over weaker snow.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 15th, 2018 4:00PM