Avalanche Forecast

Issued: Feb 24th, 2016 8:52AM

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

rbuhler, Avalanche Canada

Cariboos.

The snowpack is complex and quite variable right now. Buried weak layers remain reactive and conservative terrain selection remains critical.Extra caution is required during the heat of the day, especially on sun exposed slopes and around cornices.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

A ridge of high pressure keeps the region dry Thursday and Friday before a weak storm system arrives Saturday. Thursday is expected to be mainly sunny with light alpine winds from the southwest. Freezing levels are expected to drop below valley bottom overnight and reach 1500-1700m on Thursday afternoon. Friday is expected to be mainly sunny in the morning with increasing cloudiness during the afternoon. Alpine winds are expected to be moderate from the southwest and freezing levels are forecast to potentially reach 2000-2500m. There is still a lot of uncertainty as to how warm it will get on Friday and whether the warm air will make it to the Cariboos. A weak storm front is currently forecast to reach the region Friday overnight bringing 5-10cm of snowfall on Saturday.

Avalanche Summary

On Tuesday, several natural size 1 loose avalanches were reported. Also reported was one natural size 2 loose avalanche from a northwest aspect at 2800m. On Monday, two size 2.5 cornice releases were reported from north aspects.

Snowpack Summary

Surface hoar growth is being reported in sheltered areas as well as near surface faceting. Wind affected surfaces are being reported in the alpine and large cornices are reported to be weak. The surface hoar and/or crust layer from early February is now down 70-90cm and remains reactive in snowpack tests. This layer is expected to become most reactive during the heat of the day, especially on sun exposed slopes.

Problems

Persistent Slabs

A weak layer of surface hoar and/or a crust down 70-90cm remains susceptible to large triggers such as cornice falls or smaller avalanches stepping down. Wide fracture propagations are likely.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Choose conservative lines and watch for clues of instability.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Wind Slabs

Lingering wind slabs in the alpine may still be reactive to human-triggers.

Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Large and fragile cornices are will likely continue to fall of ridge crests with sun exposure and temperature fluctuations. Not only are they a hazard in themselves, but also a heavy trigger for slabs on the slope below.

Cornices become weak with daytime heating. >Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 25th, 2016 2:00PM