Avalanche Forecast

Issued: Mar 21st, 2019 5:02PM

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

jsmith, Avalanche Canada

Lizard-Flathead.

Naturally triggered loose wet avalanches remain likely on Friday. Avoid sun exposed slopes during the heat of the day.

Summary

Confidence

High -

Weather Forecast

THURSDAY NIGHT: Clear skies / Light, southeasterly winds / Alpine low 6 C / Freezing level 3000 m.FRIDAY: Sunny / Light, westerly winds / Alpine high 6 C / Freezing level 2800 m.SATURDAY: Mix of sun and cloud / Light, northerly winds / Alpine high 0 C / Freezing level 2400 m.SUNDAY: Snow/rain; 5-10 mm. Â / Light, southeasterly winds / Alpine high -3 C / Freezing level 1700 m.

Avalanche Summary

Wednesday's reports show continued loose wet avalanches reaching size 2 on sun-exposed aspects. Several avalanches that began as loose wet point releases, then triggered small slabs which entrained or gouged out additional mass, significantly increasing the size and destructive potential of the avalanche.Reports from Sunday and Monday showed a continuation of natural loose wet avalanche activity focused on sun exposed aspects, with some releases reaching size 2.5 as they gouged into the snowpack to entrain more mass. Several large persistent slab releases have also been noted failing on large alpine features and reaching size 2.5. Failure planes in these events seem to indicate faceted snow in the mid-snowpack. At least one northeast aspect was included in these reports, suggesting some increasing potential for shaded aspects.Natural avalanche activity is expected to continue until things cool off a bit.

Snowpack Summary

Upper snowpack: Getting warm and moist during the day, maybe forming weak crusts overnight that deteriorate during the day. On sunny aspects the upper snowpack has become increasingly isothermal (slushy and cohesionless) with successive days of warming. Mid-pack: The mid-snowpack consists of weak facets (sugary snow). Recent loose wet avalanches have been gouging into this faceted snow and entraining additional mass. Occasional slab fractures have also initiated above these facets.The lower snowpack has recently been reported to be strong in deep snowpack regions, but its strength is in doubt in shallow areas where the long, cold drought in February weakened the basal (bottom of the snowpack) layers. Some of the largest recent slab avalanches have initiated in shallow snowpack areas in the alpine.

Problems

Loose Wet

Sunshine and warm temperatures are peeling away layers of recent snow on sunny slopes as loose wet slides. Many recent loose wet avalanches have been entraining mass by gouging into the snowpack or triggering slabs.

Avoid exposure to steep, sun exposed slopes when the solar radiation is strong.Be aware of overhead hazards and avoid exposure to avalanche runout zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Wet Slabs

As the upper snowpack becomes moist or wet with warm temperatures and sunshine, the chance of wet slabs failing on weak, faceted snow in the mid snowpack increases. This repetitive stress test will be underway once again on Thursday.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Loose wet avalanches may gain mass and destructive potential by triggering slabs.

Aspects: East, South East, South, South West, West, North West.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 22nd, 2019 2:00PM