Avalanche Forecast

Issued: Mar 11th, 2019 4:24PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs and Loose Dry.

Ruari Macfarlane, Parks Canada

Jasper.

New snowfall and strong winds are a sure recipe for a reactive Wind Slab problem. Variable snowfall amounts are forecast throughout the bulletin region overnight ; Alpine hazard may remain Moderate in the drier Marmot & Maligne regions.

Summary

Weather Forecast

A cold front tonight provides a burst of snowfall, followed by a cooling, clearing trend.Monday night: Snowfall, 5cm forecast (but upto 12cm in the Icefields area).Â StrongÂ SW winds slowly easing. Treeline Low -11Tuesday: A few clouds (Broken cloud in the South).Â Winds ease to Light NW.Â Treeline High -8. Weds: Clear, cool, light winds.

Snowpack Summary

New snow accumulating over a variety of old surfaces (loose facets in sheltered terrain, wind affected in exposed areas, sun crust to treeline to solar aspects) . The mid pack is relatively strong for the region, supportive to skis in most areas. Isolated surface hoar is still reactive at/below tree line, South of the Icefields.

Avalanche Summary

No new avalanches observed Monday. On Sunday, A flight along the 93N observed a Size 2 cornice fall, not triggering any slab on the slopes below; and several small Loose Dry avalanches on steep, South facing alpine slopes. One large Whumph on flat treeline terrain South of the Icefields, on January 18 surface hoar, down 40cm.

Confidence

Forecast snowfall amounts are uncertain on Tuesday

Problems

Wind Slabs

Fresh wind slabs will continue to grow throughout Monday night, lee to Strong SW winds. Expect these to be larger and more prevalent in the icefields, which is catching the brunt of the storm.

Watch for Wind Slabs low on slopes, and in usually sheltered terrain, due to previous extreme winds.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

Skiier triggered Loose Dry avalanches increase in sensitivity Monday (steep sheltered areas), with new snowfall overlying loose facets.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.Minimize exposure to terrain traps where the consequences of a small avalanche could be serious.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 12th, 2019 4:00PM