Avalanche Forecast

Issued: Apr 22nd, 2014 8:35AM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Much cooler conditions on Wednesday will tighten up the snowpack, but still be aware of periods of intense solar radiation that can rapidly increase the avalanche danger on solar aspects.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Temperatures should drop through the night and be much cooler tomorrow. Highs of only -6 degrees are expected Wednesday with freezing levels near 1600m. Winds will be moderate to strong from the West. Wed and Thurs will bring a mix of sun and cloud, but Fri and Sat may see flurries with small accumulations.

Avalanche Summary

Observations were limited, but one size 3.5 wet slab was observed on a North and NE aspect at 2400m. This slide likely occurred in the past 24hrs during a period of warming. This slide stepped to ground along much of it's 800 metre wide fracture line.

Snowpack Summary

Spring conditions. The snowpack is settling rapidly. Surface crusts are melting during the day and re-freezing at night. The snowpack has gone isothermal at lower elevations on the warmer days (including today). Even North aspects have been affected with moist snow as high as 2500m. One large recent avalanche has occurred on a North aspect (see Avalanche Activity). Where cornices exist they are large and sagging.

Problems

Deep Persistent Slabs

The basal weak layers have become reactive with the recent Spring weather. Cooler conditions on Wednesday will reduce the likelihood of triggering this problem, but any daytime heating or solar radiation could increase avalanche activity.

Cornices become weak with daytime heating. >Choose the deepest and strongest snowpack areas on your run.>Avoid exposure to solar aspects overhead, large avalanches may reach the end of run out zones.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Loose Wet

If the sun pokes thought the clouds, radiation-triggered sluffs are possible.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 23rd, 2014 2:00PM