Avalanche Forecast

Issued: Mar 18th, 2019 7:11PM

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

jasper snow safety, Parks Canada

Jasper.

Highway 93N and Maligne road remain closed for Avalanche Control. Check Alberta 511 for details and updates.Avoid avalanche terrain on solar aspects, where a natural avalanche cycle is underway. Polar aspects are cooler, but activity is increasing.

Summary

Weather Forecast

In like a Lion! Spring is suddenly here in the Rockies and the damage to the snowpack is extensive. Very strong solar effect, with clear skies forecast all week. Freezing levels will continue to rise; to over 3000m on Tuesday / Wednesday, slowly falling Thursday. Light winds all week. Treeline high was above +10 on Monday, and warmer expected...

Snowpack Summary

The snowpack remains dry on polar (shady) aspects, at treeline & alpine elevations. Elsewhere (solar aspects) it is quickly transitioning to Spring. Thin overnight crust recovery, breaking down quickly daily. Isothermal snowpack Below Treeline on solar aspects. As the snowpack warms, the Deep Persistent layers may become active on polar aspects.

Avalanche Summary

Numerous large (to size 2.5), Loose Wet avalanches observed on solar aspects at all elevations. Several large (Size 2-3) Wet Slabs observed on solar slopes Monday (Natural at Alpine and Treeline elevations, and with explosives control Below Treeline). Several small Loose Dry avalanches observed Monday in steep alpine terrain on NE aspects.

Confidence

The weather pattern is stable

Problems

Loose Wet

Progressively rising hazard over the day. Expect natural and human triggered loose wet avalanches on all sunny slopes, especially where steeper than 35 degrees. These are gouging to ground in thin areas.

Start and finish early before the surface crusts melt.Avoid solar aspects.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Wet Slabs

As the upper snowpack becomes saturated with water, Wet Slabs are failing on solar aspects. In shallow areas, these are failing on the basal layers.

If triggered loose wet sloughs may step down to deeper layers resulting in larger avalanches.Avoid exposure to overhead solar avalanche terrain, avalanches may reach the end of run out zones.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Mar 19th, 2019 4:00PM