Avalanche Forecast

Issued: Mar 19th, 2016 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Quality of overnight freeze will play a strong factor in stability during the day on Sunday (see weather forecast tab for additiona details). Freezing level was close to 2400m on Saturday and forecast to be higher on Sunday.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

Forecasts for the next 24hrs are calling for cloud to move in overnight, and a mix of sun and cloud throughout the day tomorrow. Cloud cover overnight on Saturday will be a key thing to note with regards to stability on Sunday. If clouds move in, it is unlikely that the snowpack will get any re-freeze overnight and stability will deteriorate earlier in the day on Sunday. If there are no clouds, the snowpack should get a good freeze overnight and stability will deteriorate as the sun comes out and temperatures warm up throughout the day much like it did on saturday. So, pay attention to the quality of the freeze overnight and cloud cover.

Avalanche Summary

Numerous loose wet avalanches up to sz 1 were observed. Field teams were down from the Spray area early in the day but we suspect that there were some solar triggered avalanches initiated later in the day.

Snowpack Summary

Strong solar radiation influence throughout the region today with temperatures at 2200m of 5C. Moist surface snow was being encountered up to ridgelines and loose wet avalanches were being observed from steeper terrain into the Alpine. Northern aspects remained dry with isolated windslabs along ridgelines and in gullies features up to 40cm thick. Field tests on Friday were showing that these slabs were failing in the moderate range with not to much propagation. Cornices are still large and failures of these features is still common. So far, pretty much every cornice failure has triggerred a substantial avalanche on the underlying slopes that failed either at or near ground.

Problems

Persistent Slabs

Wind slabs up to 40cm thick are present in lee and cross-loaded features in alpine areas and in very specific locations at treeline.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Caution in lee and cross-loaded terrain near ridge crests.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Cornices

Pretty much every cornice that has collapsed has triggered a large avalanche on the underlying slopes. Avoid travel underneath cornices at this time.

Cornices become weak with daytime heating. >Pay attention to overhead hazards like cornices.>Stay well back from cornices.>

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

3 - 6

Deep Persistent Slabs

Thin snowpack areas are places where you may be able to awaken the deeper basal instabilities. Choose routes that avoid these areas especially in steeper snowpack areas.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

3 - 6

Valid until: Mar 20th, 2016 2:00PM