Avalanche Forecast

Issued: Feb 7th, 2016 8:20AM

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

Avalanche Canada pgoddard, Avalanche Canada

Skyrocketing temperatures make avalanche forecasters nervous. Deeply buried weak layers could wake up, creating very large avalanches.

Summary

Confidence

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

Weather Forecast

Bring out the flip flops! A strong ridge of high pressure is expected to bring mainly sunny skies (above valley cloud) with no precipitation for the next three days. A warm southerly flow causes the freezing level to rise as high as 3000 m. Alpine temperatures should be well above 0.For more details check out http://www.avalanche.ca/weather.

Avalanche Summary

A natural and artificially-triggered cycle of size 1-3 avalanches occurred on Saturday in response to new snow and very strong winds. The largest events were in the northern Purcells, including Quartz Creek. These are suspected to have failed on the early January persistent weak layer. Numerous persistent slabs have been triggered this week or so in the north. On Friday, a snow cat triggered a size 2 persistent slab on a SE aspect near 2300 m near Golden. Last Saturday, a size 3 sledder-triggered avalanche occurred in the Gorman Creek riding area. Around the same time, a skier triggered a size 3.5 persistent slab a few drainages to the south of Gorman Creek on a north-facing alpine slope. Forecast warming may increase the reactivity of the persistent slab.

Snowpack Summary

Strong to extreme SW winds on Saturday created wind slabs and cornices in many areas. Wind slabs may be found lower in the start zones than normal due to the high wind speed. The early January surface hoar/ facet layer is typically down 70-90 cm. Recent very large avalanches have been failing on this interface in the north of the region (see avalanche discussion). In general, the lower snowpack below this layer is well settled and strong, apart from some thin snowpack areas where basal facets exist.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent strong to extreme winds left wind slabs and fragile cornices on a variety of slopes. Forecast sun and warming may make these prone to failure over the next few days.
Travel on ridges to avoid freshly wind loaded features. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Pay attention to overhead hazards like cornices.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
The persistent slab problem demands respect, especially in the north of the region. Very large avalanches are possible with human triggers, or a wind slab or cornice fall. Forecast warming is expected to increase the sensitivity of this problem.
Minimize exposure to sun exposed slopes when the solar radiation is strong.>Be cautious around open slopes and convex rolls at and below treeline where buried surface hoar may be preserved. Big alpine features are also suspect.>Be aware of the potential for remote triggers and wide propagations due to a layer of buried surface hoar and/or facets. >Now is a good time to make conservative terrain choices.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Feb 8th, 2016 2:00PM