Avalanche Forecast

Issued: Mar 17th, 2018 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Ski quality has improved, just watch for localized storm slab formation and how that is bonding to the surface below. It should stay cloudy Sunday but local danger could increase if the sun pops out.

Summary

Weather Forecast

5cm and mainly cloudy on Sunday with a slight cooling trend and light NE winds. The sun will return on Monday with a more diurnal pattern.

Snowpack Summary

20-30 cm of recent snow has formed a variable soft slab on some features that is slowly bonding to the underlying surfaces, such as melt freeze crust on solar aspects and older snow layers including facets on shady aspects. Below this the majority of the snowpack is stable and has recently shown no results in tests.Â

Avalanche Summary

Forecasters had a big whumpf in the surprise pass area today. It was on a northerly aspect at 2400m adjacent to the usual ski run and was found to be a 30cm soft slab over facets. Other storm slabs to size 2 have been seen over the last 24 hours including 1 below the ice climb "the tease" and on Cathedral Mountain.

Confidence

Timing or intensity of solar radiation is uncertain on Monday

Problems

Storm Slabs

20-30cm recent snow has formed a soft slab and has seen recent human triggering. Dig down to look at how the new snow is bonding to the surface below, as there are a variety of crusts, facets, and old snow depending on aspect and elevation.

The storm slab may be more sensitive to human triggering on solar aspects where it sits on sun crust

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 18th, 2018 4:00PM