Avalanche Forecast

Issued: Apr 5th, 2019 4:00PM

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

tim haggarty, Parks Canada

Banff Yoho Kootenay.

While it feels like spring Below Treeline, fresh snow, strong winds and cooling temperatures will keep it feeling like winter in the Alpine through the weekend. Crusts make for rough travel up to treeline where dry snow is found on shaded aspects.

Summary

Weather Forecast

A series of lows will affect the region starting Friday night as the remnants of the first reaches the divide. Around 5cm is expected by Saturday morning with light to moderate SW winds that may increase to strong west by mid morning. Expect both the winds, and the flurries to continue through midday Sunday before the next low approaches.

Snowpack Summary

Up to 5cm recent snow at upper elevations. Melt-freeze crusts on all aspects up to 2000m and higher all other aspects. On North and East aspects in the alpine, up to 30cm of unconsolidated snow can be found. Below this, a stiff slab overlying weak facets remains a concern in some places and a weak, faceted snowpack, remains a concern in thin areas.

Avalanche Summary

No new avalanches were observed today.

Confidence

Problems

Persistent Slabs

A hard slab sitting over weak facets up to 60cm down remains a concern where found: mainly on N aspects in the alpine. We have seen a few human triggered avalanches in steep, isolated features such as moraines and glacier rolls over the past week.

Dig down to find and test weak layers before committing to a line.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Wind Slabs

With up to 30cm of unconsolidated snow available for transport and more new snow incoming, expect the strong winds in the forecast for Saturday to lead to the rapid formation of new slabs.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Wet

This problem is directly related to daytime heating and solar inputs. Even on a cloudy day localized solar effect can quickly change the snow stability. With new snow expected to fall over existing crusts, monitor conditions closely for change.

Use extra caution on solar slopes or if the snow is moist or wet.Travel early before the heat of the day, and avoid big slopes in the afternoon.

Aspects: South East, South, South West, West.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Apr 6th, 2019 4:00PM