Avalanche Forecast

Issued: Feb 26th, 2015 4:03PM

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

jon stuart-smith, Parks Canada

Waterton Lakes.

Another 10-20cm of snow was a welcome sight the last couple of days. The skiing has improved but be cautious of the extremely icy crusts that are hiding underneath. Going for a slide on this crust could have serious consequences in the wrong place.

Summary

Weather Forecast

Cool temperatures, overcast skies and maybe a few cms of snow are forecast for Friday. The snow should taper off by Saturday but temperatures will remain below -10 for daytime highs through Saturday. Light north winds will continue until Saturday as well, maybe blowing to moderate in the alpine. Sunday should clear off and start to warm up.

Snowpack Summary

The recent upslope storm left 20-30cm of new snow. Light NW winds with this storm deposited slightly more to unusual slopes. This new snow is sitting on crusts on steep sun facing slopes or old windslabs (again from NW winds) at ridge crests. The Feb 14 crusts is now down 25 to 55cm and carries well below 2000m. In places this crust is very slick.

Avalanche Summary

The new snow has been sluffing out of steep terrain over the last 24 hours but there has been no evidence of any deeper avalanches.

Confidence

Problems

Wind Slabs

Buried windslabs are hiding under the recent low density snow at ridgecrests and lee features. New slabs will develop over Fri/Sat with NE winds and 20-30cm available for transport. This will be touchy until temperatures start to warm up next week.

Use caution in lee areas. Recent wind loading have created wind slabs.Avoid travelling in areas that have been reverse loaded by winds.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

Now 70 to 180cm deep these slabs continue to stand out as a concern in the TL and ALP areas where there is not a strong Jan 31 crust over them (2200m+). Be particularly mindful in thin snowpack areas where this layer is more likely to be triggered.

Carefully evaluate and use caution around thin snowpack areas.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 1st, 2015 4:00PM