Avalanche Forecast

Issued: Apr 11th, 2017 4:00PM

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.

deryl kelly, Parks Canada

Jasper.

Rapidly changing hazard is a hallmark of spring skiing! Be aware of the potential changes that may effect your route over a whole day!

Summary

Weather Forecast

A continued scattering of flurries through the forecast area. Forecast models calling for 10 cm but, it seems to be variable in both location and accumulation. Expect warm alpine temps near -3 with freezing levels rising to 1800m.

Snowpack Summary

Icefields has 10cm of soft snow on a solid mid-pack bridging the weak base above 2000m. The base is a combination of weak facets and depth hoar mixed around a Nov rain crust. A consistent melt-freeze cycle is occurring below tree line. Surface crusts are breaking down by mid morning.

Avalanche Summary

No new avalanches observed or reported

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Wednesday

Problems

Deep Persistent Slabs

The deep instability could be triggered by large loads such as a cornice failure or a surface avalanche. Human triggering is most likely from shallow spots or on steep unsupported slopes.

Be cautious in shallow snowpack areas where triggering is more likely.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Cornices

Cornice failure is hard to predict but likelihood increases with sun, warm temperatures, and wind-loading.There are some very large cornices out there. Wise to give them a wide berth.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Loose Wet

Isothermal conditions are possible as crusts break down by late morning. Gauge the extent of the overnight freeze relative to how quick it will move into being reactive.

If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Minimize exposure to steep slopes on warm or sunny days.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Apr 12th, 2017 4:00PM