Avalanche Forecast

Issued: Mar 15th, 2019 5:26PM

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

jsmith, Avalanche Canada

Cariboos.

Warming temperatures have settled the recent storm snow into a cohesive slab sitting on weak facets (sugary snow) that is ripe for human triggers; intense solar radiation will increase the likelihood of human triggered avalanches.

Summary

Confidence

Moderate -

Weather Forecast

FRIDAY NIGHT: Partly cloudy with some clearing / Light, westerly winds / Alpine low -10 / Freezing level below valley bottom.SATURDAY: Partly cloudy in morning becoming mostly sunny / Light, southwesterly winds / Alpine high 2 / Freezing level rising to 1800 m.SUNDAY: Sunny / Light, northwesterly winds / Alpine high 5 / Freezing level rising to 2200 m.MONDAY: Sunny / Light, westerly winds / Alpine high 7 / Freezing level rapidly rising to 3000 m.

Avalanche Summary

On Thursday, a few size 1 rider triggered persistent slab avalanches were reported on northerly aspects at treeline and below.On Wednesday, several naturally triggered, size 1.5 persistent slab avalanches and a few explosive triggered persistent slabs up to size 2.5 were reported on primarily north aspects at treeline and above. On Tuesday, there were reports of several human triggered persistent slab avalanches up to size 2. A few of these were triggered remotely (from a distance). There were also several reports of natural persistent slab avalanches up to size 3. These avalanches occurred on all aspects and at all elevation bands.

Snowpack Summary

10-15 cm of new snow brings the recent storm snow to 30-55 cm. This snow is sitting on facets (sugary snow), as well as surface hoar (feathery crystals) in sheltered areas and a crust on sun exposed slopes. At lower elevations, a weak layer buried in mid January can be found approximately 50-90 cm deep. This layer consists of surface hoar and facets, and may be combined with a crust on south facing slopes. This layer has been most reactive at lower elevations below treeline. Avalanche activity has dropped off significantly, however, the forecast warming event may awaken this layer in areas such as steep cutblocks.The lower snowpack is generally considered to be strong, except for shallow, rocky areas in the alpine.

Problems

Persistent Slabs

Warming temperatures have settled the recent storm snow into a cohesive slab sitting on weak facets (sugary snow) that is ripe for human triggers; especially at treeline and above.

Avoid convex slopes on rocky terrain with a variable snow depth.Avoid steep terrain where the snow feels moist or slabby.Use extra caution on solar aspects where the new snow is sitting on a crust.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Loose Wet

Pin-wheeling snow below cliffs is a common sign that loose wet avalanches are becoming more likely.

Reduce exposure to over-head hazards such a large cornices during periods of strong solar radiation.Avoid 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: East, South East, South, South West, West.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Mar 16th, 2019 2:00PM