Avalanche Forecast Purcells

Date Issued: Valid Until:

Avalanche Canada jsmith, Avalanche Canada

Avalanche Forecast

Sun Apr. 14th ยท 3:31PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low
Wind Slabs Wind Slabs
Loose Wet Loose Wet

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low
Pay attention to changing conditions with elevation/aspect. Watch out for small wind slabs below ridgetops and loose wet avalanches on sun-exposed slopes if the sun comes out.

Confidence

High -

Weather Forecast

SUNDAY NIGHT: Partly cloudy / Light, southwesterly winds / Alpine low -8 C / Freezing level 1000 m..MONDAY: Mix of sun and cloud / Light, southwesterly winds / Alpine high -5 C / Freezing level 1600 m.TUESDAY: Mix of sun and cloud / Light, southwesterly winds / Alpine high -4 C / Freezing level 1800 m.WEDNESDAY: Mix of sun and cloud / Light, westerly winds / Alpine high -1 C / Freezing level 2200 m

Avalanche Summary

No new avalanches were reported in this region on Saturday.On Friday, explosive cornice control work dropped a large cornice on a rocky slope which triggered a size 2.5 slab avalanche 50 cm deep on a northeast aspect.

Snowpack Summary

Currently, the snowpack structure changes dramatically with elevation and aspect. 5-10 cm of snow Saturday night and moderate southwesterly winds have created small wind slabs in lee features below ridgetops. The new snow is sitting on a melt/freeze crust, except for north facing terrain above 2100 m. where the old snow surface remained dry and small surface hoar (weak, feathery crystals) may be present in isolated locations. Weak facets (sugary grains) remain at the bottom of the snowpack in the alpine creating a low likelihood, high consequence scenario that would likely require a large trigger to initiate an avalanche. Steep, rocky areas with a shallow or highly variable snowpack are the most likely places to trigger a very large avalanche on this layer.Below roughly 1900 m, the snowpack is moist and is melting rapidly at lower elevations. Check out this useful link for managing avalanche hazard during spring conditions HERE.

Problems

Wind Slabs

Wind Slabs

5-10 cm of snow Saturday night and moderate southwesterly winds have created small wind slabs in lee features below ridgetops.

Avoid wind loaded slopes below ridgetops.Pay attention to changing conditions with elevation/aspect.Use small slopes without consequence to test the bond of the new snow.

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

Elevations: Alpine.

Likelihood

Likely - Possible

Expected Size

1 - 1.5

Loose Wet

Loose Wet

When the sun comes out, expect the loose wet avalanche hazard to increase rapidly.

Cornices become weak with daytime heating, travel early on exposed slopes.Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.Avoid sun exposed slopes when the solar radiation is strong, especially if the snow is moist or wet.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1.5