Avalanche Forecast

Issued: Jan 25th, 2015 10:35AM

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

Tim Haggarty, Parks Canada

Waterton Lakes.

Heating has weakened the snowpack and our ice climbs as well. The Akamina Parkway was closed at 8 AM Sunday morning as falling ice blocked the road. TH

Summary

Weather Forecast

Heating Saturday and Sunday will likely prove to have provided the greatest shock to the snowpack however an increase in the freezing levels and temperatures appears to be in the cards for Monday and is cause for continued concern. Winds should peak Sunday afternoon however little snow remains available for transport. Cooling begins Tuesday.

Snowpack Summary

A strong chinook has brought light amounts of rain, strong winds, and very warm temperatures to the divide and created crusts to around 19000m. Clear skies allowed a strong solar input Saturday creating loose snow avalanches and strong crusts on steep south slopes. TL and above prominent windslabs have formed on N and E lee features.

Avalanche Summary

A significant solar cycle occurred Saturday with loose wet sluffs initiating at treeline elevations and triggering recent windslabs, persistent slab, and basal facets in thin snowpack areas to size 2.

Confidence

Freezing levels are uncertain

Problems

Wind Slabs

Now 20 to 40cm deep, these slabs have developed along with Cornices due to Westerly winds and appear to be quite obvious in open lee features. Although most developed at Treeline and above these slabs appear reactive at lower elevations as well.

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

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Now 40 to 120cm deep. These slabs still demand attention particularly with the warm temperatures. Be mindful in thin snowpack areas, where this layer is more likely to be triggered.

Be aware of thin areas that may propogate to deeper instabilites.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wet Slabs

Small solar sluffs triggered the persistent slabs plus deep slabs failing on facets at the base of the snowpack Saturday. The snowpack has been weakened by heating and this is most pronounced at lower elevations, on solar slopes, and in thin areas.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Do not travel on slopes that are exposed to cornices overhead.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 28th, 2015 4:00PM