Avalanche Forecast

Issued: Feb 24th, 2016 4:00PM

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

garth lemke, Parks Canada

Jasper.

Danger has the potential to increase with intense sun especially on steep Southerly aspects in the afternoons.

Summary

Weather Forecast

The next few nights will be cold and -3 to -6 during the day with scattered clouds, mainly sunny, and light west winds. No new snow is expected until Saturday.

Snowpack Summary

Approximately 20cms of soft surface snow in sheltered locations at TL over a supportive mid-pack. This is sitting on a weak basil facet layer. BTL, the HS is more inconsistent in depth and support. Solar aspects have a thin sun crust down 20cms and producing moderate to hard resistant compression test results. Recent sun may create surface crusts.

Avalanche Summary

No field trip Wednesday. Tuesday observed two new avalanches observed above the Maligne road which appeared to be solar triggered. Some cornice failures also noted in Icefields area which triggered the basal weakness.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

Wind slabs are bonding well, however caution is still warranted in immediate lees and cross loaded terrain above treeline.

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

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Persistent weak layers of decomposed surface hoar, facets, and depth hoar are in many locations. These layers have been stubborn to trigger underfoot but could trigger with a cornice failure or from shallow spot.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. Avoid steep slopes below cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Loose wet avalanches, especially in the later afternoon with warm sunny skies, are possible on south and westerly aspects. Probability increases with sun.

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

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 25th, 2016 4:00PM