Avalanche Forecast

Issued: Feb 1st, 2019 5:31PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Storm Slabs and Persistent Slabs.

kdevine, Avalanche Canada

North Columbia.

Rapid loading from heavy snowfall and wind is the perfect recipe for avalanches. Avoid avalanche terrain.

Summary

Confidence

High -

Weather Forecast

FRIDAY NIGHT - Flurries, 5-15 cm / southwest winds, 30-50 km/h / alpine low temperature near -6SATURDAY - Cloudy with scattered flurries, 3-5 cm / southwest winds 20-30 km/h / alpine high temperature near -7SUNDAY - Mainly cloudy with isolated flurries, 3-5 cm / northeast winds 10-15 km/h / alpine high temperature near -15MONDAY - Sunny with cloudy periods / northeast winds, 10-15 km/h / alpine high temperature near -16

Avalanche Summary

A widespread natural avalanche cycle was reported on Friday, as were numerous human triggered avalanches to size 1.5. Some of these were remote triggered (triggered from a distance).Numerous human triggered avalanches to size 2 were reported in the region on Thursday. Most of these were on northerly aspects at treeline. They reportedly failed on the persistent weak layer that was buried in mid January.On Tuesday and Wednesday, numerous natural and human triggered avalanches were reported on both north and south aspects at all elevation bands. It is likely that some of these occurred on the mid January persistent weak layer as well.Also on Tuesday, in the neighboring Glacier National Park region, a human triggered size 3 avalanche occurred on a steep southeast facing slope in the alpine. There is a detailed report on the Mountain Information Network here

Snowpack Summary

40-80 cm of snow has fallen in the North Columbia region since Thursday. This new snow sits on surface hoar (feathery crystals), facets (sugary snow), wind slabs and a crust on sun-exposed slopes.A persistent weak layer that was buried in mid January is now buried 50-100 cm. This layer consists primarily of surface hoar, however there is also a crust associated with it on sun-exposed slopes. This layer has been most reactive at treeline and below.

Problems

Storm Slabs

40-80 cm of new snow has fallen in the region since Thursday. The new snow will likely be very reactive to human triggers.

If triggered, storm slabs may step down to deeper layers and result in even larger avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

50-100 cm of snow is now sitting on a persistent weak layer of surface hoar and crust. The North Columbia region has been the "hot spot" of activity on this layer, with more reactivity reported here than in neighboring regions.

Avoid convex rolls at and below treeline where buried surface hoar may be preserved.Use extra caution around steep open terrain features, such as cutblocks, gullies and cutbanks.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Feb 2nd, 2019 2:00PM