Avalanche Forecast

Issued: Jan 15th, 2017 4:17PM

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

jonas hoke, Parks Canada

Waterton Lakes.

Sensitivity of weak layers may increase as temperatures approach zero degrees. Watch for signs that warming is affecting the snowpack (snowballing, trees dripping, moist surface snow etc.)

Summary

Weather Forecast

The warm dry air aloft that has been flooding in from the West producing Chinook conditions will persist through Monday. On Tuesday an "atmospheric river" hitting the coast will make it's way inland. Predictions of how far inland this will push vary, but expect to see increased cloudiness, ongoing warm temps and some precipitation in our area.

Snowpack Summary

Soft snow exists in sheltered areas, but has been stripped off or blown into Wind Slabs by strong SW winds in all open areas. Facetted layers in the mid and lower snowpack remain a concern, particularly in shallow snowpack areas where facetting is more pronounced and triggering is more likely.

Avalanche Summary

Small natural Wind Slab avalanches have been observed recently.Â A Large (Size 3) Deep Persistent slab avalanche was observed in Alpine terrain last Friday, at 2250m on a North aspect. Triggered by a small Wind Slab hitting a shallow spot, this propagated across the slope into the adjacent deeper snowpack and was up to 2m thick in places.

Confidence

Freezing levels are uncertain

Problems

Deep Persistent Slabs

Weak faceted layers from previous cold temps in the mid and lower snowpack remain a concern, particularly in shallow snowpack areas where facetting is more pronounced and triggering is more likely.

Avoid shallow snowpack areas where triggering is more likely.Use caution on open slopes and convex rolls

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 18th, 2017 4:00PM