Avalanche Forecast

Issued: Apr 28th, 2017 4:08PM

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

Rupert Wedgwood, Parks Canada

Jasper.

Spring conditions are here and fine skiing can be found at all elevations. Pay close attention to the freezing levels and plan to finish your day before the afternoon avalanche cycle starts.

Summary

Weather Forecast

With the Jet Stream to the South cool temps dominate through the weekend. With freezing levels descending to the valley bottom snowpack overnight recovery will be good on Saturday morning. Over the weekend this will remain at 1,600m. Rain at lower elevations and snow in the alpine over the weekend.

Snowpack Summary

On Northerly facing slopes above treeline up to 20 cm of loose new snow sits over a well consolidated upper snowpack. Melt freeze crusts are ubiquitous to treeline above which their distribution narrows to solar slopes up to 2600m. The mid-pack is consolidated and bridges the weak base. Winter conditions exist in the high alpine on Northerly slopes

Avalanche Summary

Avalanche activity will increase with thermal inputs such as rain, direct solar radiation and daytime warming. After a good nights freeze the danger will gradually increase during the day and peak from14:00 until sundown. Likely trigger spots close to rocks, off cliffy terrain and shallow snowpack areas.

Confidence

Problems

Loose Wet

Freezing overnight temperatures decrease the danger in the morning until it warms up increasing the hazard. Most widespread during the late afternoon on solar facing slopes. Sluffs from rocks can trigger large slides once the snow is wet.

Pay attention to sluffing off cliffs and steep solar terrain, signs of a warming snowpack.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: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Cornices

Cornice failures are still being noted periodically on West aspects 2500-2800m.

Give cornices a wide berth when travelling on or below ridges.Avoid travel on slopes that are exposed to cornices overhead.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

The deep instability is well bridged by a solid mid-pack; however, it could be triggered by a cornice failure.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 29th, 2017 4:08PM