Avalanche Forecast

Issued: Apr 6th, 2015 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Solar radiation is very intense at this time of year. Start your trip early and finish early to take advantage of the overnight freeze. Good skiing is found on northerly aspects at higher elevations.

Summary

Confidence

Good

Weather Forecast

Tuesday will bring cloudy skies with some sunny periods. No precipitation is expected and alpine temperatures should reach a high of -3 °C. Winds will be light from the northwest at 10 km/h. The freezing level should climb to 2000 metres. The rest of the week looks mostly sunny with light winds and freezing levels near 2200m.

Avalanche Summary

A few small loose dry avalanches were observed today on all aspects in steep alpine terrain.

Snowpack Summary

The recent storm snow has settled out to between 25 and 30cm at treeline elevations. This sits on a wide variety of previous surfaces including crusts in many locations. Field teams observed planar shears in the moderate range below the recent storm snow in snowpack tests today. Soft wind slabs are present in isolated alpine terrain, particularly in lee and cross-loaded features. Solar aspects have a new sun crust on the surface up to at least 2700m. These crusts remained frozen today due to cloudy skies and cool temperatures, but any input of solar radiation was triggering loose wet slides and producing moist snow yesterday.

Problems

Loose Wet

The April solar radiation is very strong and any sunny periods quickly lead to moist snow and the possibility for loose wet avalanches.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

Wind slabs are present in alpine terrain in lee and cross-loaded features. More extensive wind slab development is possible due to the amount of snow available for transport.

Caution in lee and cross-loaded terrain near ridge crests.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The basal weak layers have been dormant for some time, but the potential remains for a low probability, high consequence event due to the structure of the snowpack. Be mindful of this issue in shallow snowpack regions and when the snowpack warms up.

Minimize exposure during periods of heavy loading from new snow, wind.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 5

Valid until: Apr 7th, 2015 2:00PM