Avalanche Forecast

Issued: Jan 22nd, 2015 4:06PM

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

mike eder, Parks Canada

Jasper.

Should the sun peak out of the clouds for a longer period, avalanche activity will increase on the solar aspects in gully features. Also, if the weekend storm comes early it will produce rain at lower elevations with the expected warm temperatures.

Summary

Weather Forecast

Overcast skies will begin producing light snowfalls by mid afternoon in the icefields area and it will rain at lower elevations. The weekend will bring steady warm, heavy snow in the south part of the forecast area. The freezing level is expected to go up to 1800m on Saturday afternoon and stay there through the weekend.

Snowpack Summary

A highly variable snowpack exists throughout the forecasting region. Steady strong SW winds have scoured open slopes in the alpine and redistributed that snow lower on the lee aspects. Warming temperatures combined with periodic sun through the clouds could start small slides in the rocks which may step down when they hit a more open slope below.

Avalanche Summary

The sun came out in the afternoon and triggered a size 2 slab avalanche in a shallow alpine gully feature on a west facing aspect indicating that the sun is gaining strength. Below treeline, road cutbanks facing the south are creating snowballing and small loose avalanches.

Confidence

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

Problems

Wind Slabs

Strong SW winds have have scoured open slopes on solar aspects and redistributed that snow into wind slabs on lee aspects and cross loaded features. This extra load combined with a skier could be sufficient to initiate an avalanche

Be careful with wind loaded pockets while approaching and climbing ice routes.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

The weak layer of surface hoar and facets from December can still be found and may become susceptible to triggering with more snow loading.

Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Jan 23rd, 2015 4:00PM