Avalanche Forecast

Issued: Mar 29th, 2017 4:15PM

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

triley, Avalanche Canada

Lizard-Flathead.

Storm slabs are expected to continue to be reactive, and we may see some natural avalanche activity if the sun comes out. Deep persistent avalanches are more likely if we see strong solar radiation.

Summary

Confidence

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

Weather Forecast

Overnight: Another 3-5 cm with strong westerly winds and freezing levels at 1300 metres by morning. Thursday: Mix of sun and cloud as the ridge of high pressure builds on the coast and moves inland. Chance of some convective flurries, with daytime freezing up to 1800 metres. Friday: Mostly sunny with light winds and daytime freezing up to at least 2100 metres. Saturday: Unsettled with flurries or light snow, not much of a re-freeze below 2000 metres. Westerly winds developing during the day.

Avalanche Summary

Storm slab avalanches up to size 2.5 were released by explosives on Wednesday, as well as skier controlled loose wet and storm slab avalanches to size 1.5. Looking ahead, a significant concern is the potential for large deep persistent slab avalanches triggered by natural triggers such as a cornice fall. See the forecaster blog for advice on managing avalanches that are not likely, but if they are triggered, are almost unsurvivable. See (here) for details.

Snowpack Summary

25 cm of new snow overnight and another 10 during the day on Wednesday have developed storm slabs in the alpine that are 30-50 cm thick near Fernie. In the Corbin area, there was a total of 25cm in the last 24 hours. Storm snow is not bonding well to crusts in the alpine and at treeline. Below 1600 metres the snow is moist or wet. Deeply buried facets may spring to life due to the added load of the storm slabs, and the possibility of strong solar radiation over the next couple of days.

Problems

Storm Slabs

Storm slabs developed overnight that are 30-50 cm deep in the alpine. These slabs stiffened during the day due to warm temperatures. Expect storm slabs to continue to be reactive, and we may see natural activity when the sun comes out.

Be alert to conditions that change with elevation and aspect.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Watch out for wet snow at lower elevations or on sunny slopes if the sun comes out during the day.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 30th, 2017 2:00PM