Avalanche Forecast

Issued: Mar 26th, 2013 4:01PM

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

mike eder, Parks Canada

Jasper.

The sun's strength is increasing. If the skies are clear, expect the avalanche hazard to increase in the afternoon. Watch for overhead hazards. Start and finish your trips early.

Summary

Weather Forecast

A light snow flurry may occur overnight, but only trace amounts may arrive. Daytime skies are expected to remain clear or only light high clouds with strong diurnal changes in temperature through the day. Winds remain light ranging from the Southwest to the Northwest.

Snowpack Summary

A variable thick slab exists in alpine and treeline locations on a variety of aspects. It is over a strong midpack except in shallow locations where you could trigger basal facets near the ground. A suncrust with varying thickness and strength exists at all elevations on steep South facing aspects. Below treeline, the crust breaks down by midday.

Avalanche Summary

Numerous loose snow avalanches were observed on steep South through West aspects at all elevations in the Icefields areas. They originate from steep rock bands and gully features where the sun heats the rocks.

Confidence

Timing or intensity of solar radiation is uncertain on Wednesday

Problems

Deep Persistent Slabs

This continues to be the main concern with last week's avalanche activity showing deeper slabs that were sliding full depth on weak facets and in windloaded gully features on predominantly Northeast through to Southeast aspects.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Cornices

Cornices will become increasingly prone to failure as the days get warmer. A cornice failure could provide a heavy trigger for an avalanche on the slopes below. Pay attention to what is above you and the temperatures during the day.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

The sun is warming the rocks on steep rock cliffs and gully features on Southerly aspects. Loose snow avalanches are starting in these features at all elevations later in the day. Cloud cover will determine if this occurs during the day.

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

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 27th, 2013 4:00PM