Avalanche Forecast

Issued: Mar 11th, 2014 4:00PM

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

edwin knox, Parks Canada

Waterton Lakes.

Persistent instabilities are still present in our snow pack and may be triggered more easily with daytime warming. Use conservative terrain selection. CAMERON LAKE ROAD CLOSED THROUGH WEDNESDAY - check Alberta 511 for updates.

Summary

Weather Forecast

Watch for afternoon warming and sunshine with highs to 5C for Akamina Pass elevation most days. A moderate westerly flow is expected. Overnight temperatures will recover nicely so best time to travel would be early. Warming will weaken the already unstable snowpack.

Snowpack Summary

Persistent instabilities still very much a concern despite cooler overnight temps. Snowpack temps on solar aspects at 1650m showed most of the pack just below freezing as a result of the significant warming this past weekend. The weak facet layer is 70 to 170cm deep depending on aspect. Test results on it showed very easy triggering is possible.

Avalanche Summary

With moderate west winds transporting the 5cm overnight snowfall numerous small avalanches were observed by mid day Tuesday. The large cycle from the weekend ended with the overnight cooling and lower daytime temperatures but solar heating with bluebird days is a concern. Avoid slopes below cornices.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Storm Slabs

Very warm temperatures and rain to 2300 meters on March 8 and 9 has settled the near surface instabilities with cooler night time temps. Thin wind slabs may be present in some aspects on this layer.

Pay attention to overhead hazards like cornices.Travel early on frozen crusts before the heat of the day.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The weak facet layer is now buried by up to 170cm in treeline and alpine areas and below treeline is found down 50cm. Many avalanches fell over the weekend on this layer and it is a concern that may persist for some time. Triggering is possible!

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 14th, 2014 4:00PM