Avalanche Forecast

Issued: Mar 27th, 2019 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Watch for new windslabs in alpine terrain from the recent snow. Clear skies are forecast on Thursday so watch for intense solar radiation and decreases in stability.

Summary

Confidence

Moderate - Due to the number and quality of field observations on Wednesday

Weather Forecast

The pulse of recent snow is beginning to end and we are moving into more of a clearing trend for the next few days. Temperatures are forecast to be around -10C overnight and then tomorrow warming up to around +5 with freezing levels around 2200m. Clear skies are forecast so be aware that as the sun comes out and solar radiation increases stability will decrease. These decreases are most apparent on steep solar aspects, especially in thin or rocky terrain. Pay attention to the aspect you are on/under and the time of day. Early starts are key at this time of year.

Avalanche Summary

A few loose dry avalanches on steep northern aspects were observed but no new slab avalanche activity. Observations were limited due to cloud cover and conditions.

Snowpack Summary

Up to 15cm of snow has fallen over the past 48hrs with light occasional gusting into moderate SW winds. This new snow has fallen on top of a previous melt freeze crust that developed during last weeks heat wave. The main concerns at this time are isolated thin wildslabs in alpine terrain that are overlying the previous melt freeze crust as well as concerns associated with the deep persistent weak base. The freezing level on Wednesday climbed to 2200m with some moist snow being found below this elevation. Untracked areas at treeline and below are weak isothermal.

Problems

Deep Persistent Slabs

This layer becomes a concern when the melt/freeze crust breaks down with solar radiation or warming.

Be aware of the potential for wide propagations due to the presence of hard windslabs.Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Isolated windslabs in alpine terrain that have formed with the recent snow and winds. Check the bond with the underlying crusts.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Loose Wet

As conditions warm up, watch for wet slabs to start on solar aspects.

Use extra caution on solar slopes or if the snow is moist or wet.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 1.5

Valid until: Mar 28th, 2019 2:00PM