Avalanche Forecast

Issued: Mar 15th, 2019 5:01PM

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

cgarritty, Avalanche Canada

Northwest Inland.

A bit of new snow will combine with strong southwest winds to keep wind slab problems active on Saturday. The first big warm up of spring will bring deeper weak layers into consideration early in the week.

Summary

Confidence

Moderate -

Weather Forecast

Friday night: Mainly cloudy with isolated flurries bringing a trace of new snow. Moderate southwest winds. Saturday: Cloudy with increasing scattered flurries bringing approximately 5 cm of new snow. Strong southwest winds. Alpine high temperatures around -1 with freezing levels rising 1500 metres, increasing overnight.Sunday: Cloudy with sunny periods and possible isolated wet flurries, or rain below 1600 metres. Light south winds. Alpine high temperatures around +1 as freezing levels rise to 2000 metres by end of day and increase overnight.Monday: Sunny with cloudy periods. Light southeast winds. Alpine high temperatures around +5 with freezing levels rising to 2500 metres, increasing again overnight.

Avalanche Summary

There were few observers in the field this week but reports showed a natural avalanche cycle of storm and wind slabs up to size 2 early in the week.

Snowpack Summary

25 to 50 cm of slightly upside down (higher density on top) storm snow has accumulated since Monday. This recent snow rests on previously wind affected surfaces, sun crusts (on solar aspects) and weak, sugary facets. The prolonged period of cold temperatures in February has had an overall effect of weakening the upper and mid-snowpack, as well as the basal snowpack in thinner areas.In the south of the region the lower snowpack is generally strong.

Problems

Wind Slabs

25 to 50 cm of storm snow from the past several days rests on a mix of weak layers. Winds have been transporting available storm snow into reactive slabs over the same period. Slabs may be particularly touchy where they rest on weak faceted snow.

Avoid freshly wind loaded features near ridge crests, roll-overs and in steep terrain.Shooting cracks, whumphs and recent avalanches are all indicators of an unstable snowpack.Analyze slopes for patterns of wind transport and observe the bond of recent snow to the old surface

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

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