Avalanche Forecast

Issued: Apr 21st, 2014 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Weather forecasts are uncertain, but Tues could produce a spring avalanche cycle due to very warm temperatures, a poor freeze Mon night, periods of sun and periods of rain. Avoid avalanche terrain when the snowpack is warm and avoid overhead hazard.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Tuesday is expected to be warm with sunny patches and a chance of light rain showers. The snowpack is not expected to get a good freeze tonight, and freezing levels on Tuesday could climb to 3000 metres. Winds are forecasted to gust up to 50km/h from the SW. Wednesday should be significantly cooler with a mix of sun and cloud and a high of -4 degrees in the Alpine.

Avalanche Summary

Nothing new reported or observed.

Snowpack Summary

Spring conditions. The snowpack is settling and grass is beginning to show at lower elevations. Surface crusts are melting during the day and then re-forming at night. The snowpack has gone isothermal at lower elevations on the warmer days and crusts are found to at least as high as 2500 metres on North aspects and much higher on solar aspects. Where cornices exist they are large and sagging.

Problems

Wet Slabs

Extremely high freezing levels on Tuesday coupled with periods of solar radiation will likely result in wet slab and loose wet avalanches. The snowpack could deteriorate early in the day as it is not expected to freeze well overnight.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Cornices become weak with daytime heating. >Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Deep Persistent Slabs

Spring conditions have awakened the basal weak layers. Full depth avalanches are possible when the temperature is warm and/or the solar heating is intense. Be aware of overhead terrain.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Apr 22nd, 2014 2:00PM