Avalanche Forecast

Issued: Mar 29th, 2014 8:00AM

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

catherine brown, Parks Canada

Glacier.

Avalanche hazard will increase today as freezing levels rise. A variety of surfaces will be changing rapidly, pay close attention to conditions as you travel.

Summary

Weather Forecast

Light precip is forecast today with freezing levels rising to 1400 m and ridge top winds SW-15. 5-10 cm of snow is forecast overnight as the freezing level falls to 1200m. Isolated flurries continue Sunday with alpine temps around -3. More sunny periods on Monday with freezing levels around Rogers pass elevation.

Snowpack Summary

On shaded and northerly aspects dry snow exists above 1500m. Soft wind loaded pockets may have formed with moderate SW winds. On solar aspects breakable sun crusts exist, and overlie a series of crusts in the top meter which react with hard planar results in tests. The Feb10 layer is down ~2m, shallower in thin areas, and continues to be a concern.

Avalanche Summary

On Thursday, skiers reported easily triggering small size 1-1.5 slabs, where the storm snow failed on convexities and unsupported slopes. On Wed, loose moist avalanches triggered by skiers when a bit of sunshine provided a lot of warmth. These avalanches ran fast and and far, into mature timber, with some growing to size 2.5.

Confidence

Intensity of incoming weather systems is uncertain on Saturday

Problems

Persistent Slabs

A weak layer down 20-30 cm is still reactive to skier-triggering. Use caution on unsupported features and convex terrain. Watch for changing conditions as temperatures warm up today and surface crusts deteriorate.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Persistent Slabs

Weak layers from early March, now buried a meter deep, are still reactive in tests. They are most likely to be triggered on solar aspects where sun crusts exist. Smaller avalanches may step down to these layers, resulting in a big avalanche.

Avoid shallow snowpack areas where triggering is more likely.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 30th, 2014 8:00AM