Avalanche Forecast

Issued: Feb 20th, 2019 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Dry and Deep Persistent Slabs.

deryl kelly, Parks Canada

Jasper.

Stable weather forecast with little change in temps and no new snow into the weekend. Keep wary to evidence of localized instability such as cracking, whumphing and, recent avalanche activity.

Summary

Weather Forecast

Columbia IcefieldsWed - Cloudy with sunny periods and isolated flurries. Alp High -12C overnight low -22CC. Ridge wind NE 10-20 km/h.Thu - A mix of sun and cloud. Precip Nil. Alp High -13C. Ridge wind w 10 km/h.A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

The upper snowpack is faceted creating a weak slab over a faint, inconsistent layer of surface hoar/facets on a crust down 40cm. The thicker snowpack spots have a strong mid-pack bridging the deep persistent basal weakness of depth hoar. Thinner snow-pack zones are much less consolidated and can act as a slab triggering the basal depth hoar.

Avalanche Summary

Field team in the Portal Creek drainage found supportive riding at tree line elevations with progressively less support below tree line.

Confidence

The weather pattern is stable

Problems

Loose Dry

Sun may act as a trigger to initiate the loose unconsolidated surface snow particularly in steep rocky terrain. Definitely a problem ice climbers should keep on radar where small slides can gain mass particularly in terrain traps.

If triggered dry loose point releases can form deeper deposits in terrain traps.Be careful of loose dry power sluffing in steep terrain..

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

It is possible to trigger deep slabs in shallow snowpack areas. Terrain management and assessment is critical to a safe day.

Minimize exposure to terrain traps where the consequences of an avalanche could be serious.Be cautious in shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Feb 21st, 2019 4:00PM