Avalanche Forecast

Issued: Mar 11th, 2018 4:00PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

The danger is Low/Low/Low in the morning, but rising with daytime warming and sun. Start and finish early and avoid exposure to solar aspects and cornices once the sun is out.

Summary

Weather Forecast

Expect the daily diurnal temperature variation to continue, each day a little bit warmer than the last. Freezing levels will rise to ~2500m later in the week, and dropping to valley bottom overnight. Clear skies will also provide a condition for intense solar radiation. Wind will remain light from the SW.

Snowpack Summary

Facetted, wind effected snow exists in the alpine. A sun crust has formed on solar aspects at treeline and below. The deeper facet layers down 80-150 cm remain weak and are currently dormant, but could become active with the warm days ahead.

Avalanche Summary

Evidence of a loose wet avalanche cycle was isolated to steep solar gullies. Also observed were a few size 2 slabs on steep solar convex rolls.

Confidence

Due to the number and quality of field observations

Problems

Loose Wet

Expect loose wet avalanches to initiate from steep rocky terrain. Watch for increasing hazard associated with prolonged sun affect. Finish very early, or better yet, avoid steep confined features all together.

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

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Wind Slabs

Alpine West winds formed windslabs last week. These are bonding, but in steep unsupported terrain, skier triggering is still possible.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Mar 12th, 2018 4:00PM