Avalanche Forecast

Issued: Mar 22nd, 2019 4:35PM

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

jsmith, Avalanche Canada

Lizard-Flathead.

Many recent loose wet avalanches have been entraining mass by gouging into the snowpack or triggering slabs and running much further than expected.

Summary

Confidence

Moderate - Timing of incoming weather systems is uncertain

Weather Forecast

FRIDAY NIGHT: Clear skies / Light, westerly winds / Alpine low 0 C / Freezing level dropping to 2500 m.SATURDAY: Increasing cloudiness in afternoon / Light, northerly winds / Alpine high 1 C / Freezing level dropping to 2000 m.SUNDAY: Cloudy with flurries; 3-5 mm. / Light, southeasterly winds / Alpine high -1 C / Freezing level 1500 m.MONDAY: Mix of sun and cloud / Light, southwesterly winds / Alpine high 0 C / Freezing level 1800 m.

Avalanche Summary

Thursdays reports show continued skier triggered loose wet avalanches reaching size 1.5 on sun-exposed aspects. Check out this video of our South Rockies Field Team HERE.On Wednesday, 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.Expect the hazard to remain elevated until the clouds arrive and the temperatures cool.

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

Many recent loose wet avalanches have been entraining mass by gouging into the snowpack or triggering slabs and running much further than expected.

Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.Avoid exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Wet Slabs

Cooling is on the way but likely not in time to reduce the hazard on Saturday. Human triggering of wet slab avalanches remains possible.

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

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 23rd, 2019 2:00PM