Avalanche Forecast

Issued: Apr 20th, 2014 4:00PM

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

garth lemke, Parks Canada

Jasper.

Plan to travel early to take advantage of the crust and be off big slopes by mid-day. The avalanche hazard will rise on slopes with prolonged exposure to the sun.

Summary

Weather Forecast

Monday will be seasonal temperatures, some cloud, and light SW winds. Tuesday will be similar yet expect precipitation developing late in the day, shifting winds from SE, snow at higher elevations likely being rain below 2500m. Some models are suggesting 25cm of snow which could translate to significant amount of rain.

Snowpack Summary

The crust is staying intact except for the steepest solar facing aspects below tree-line. The snowpack remains moist below this crust up to tree-line elevation. Higher elevations, the snowpack is a well bridged mid-pack over a faceted base. Cornices are large and ominous.

Avalanche Summary

No new avalanche observed Sunday at Maligne and Icefields.

Confidence

Freezing levels are uncertain on Tuesday

Problems

Loose Wet

Overnight recovery of the melt freeze crust is occurring; however, expect loose wet slides by mid-day especially if exposed to intense solar radiation. Gauge the amount of overnight freeze of the crust to how quickly it can destabilize.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Start and finish early before the surface crusts melt.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

No recent activity on this layer; however, triggering remains possible from thin rocky areas on loaded features.

Avoid convexities or areas with a thin or variable snowpack.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 21st, 2014 4:00PM