Avalanche Forecast

Issued: Apr 10th, 2016 8:57AM

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

triley, Avalanche Canada

Kootenay Boundary.

Spring conditions. Avalanche danger is expected to rise during the day due to continued high freezing levels and periods of strong solar radiation. Plan to travel early and monitor crusts carefully as conditions may change rapidly.

Summary

Weather Forecast

Mostly clear overnight with light winds. Cloud developing during the day on Monday with freezing levels at 2500 metres. Light to moderate southwest winds on Tuesday with mostly cloudy skies and some light precipitation and freezing levels at 2200 metres. Freezing levels dropping to 1500 metres on Wednesday with 5-10 cm of new snow expected at higher elevations.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

Cornices are large, fragile, and could trigger deep slab avalanches that run to valley bottoms. Monitoring the overnight freeze of the snow surface is very important during the spring. If the snow surface does not freeze overnight or if the crust is only a few cm thick, the effect of daytime heating and solar radiation will weaken the snowpack much more quickly than it would if there is a well frozen thick crust. This is because the crust must first melt before the sun can weaken the snowpack. Low elevation and thin snowpack areas have become isothermal, meaning the snowpack is 0 degrees Celsius throughout. An isothermal snowpack is more prone to full depth wet slab avalanches during the heat of the day.

Problems

Cornices

Natural cornice falls continue to be a concern during periods of strong solar and high freezing levels.

Pay attention to overhead hazards like cornices. >Cornices become weak with daytime heating, so travel early on exposed slopes. >Give cornices a wide berth when traveling on ridges. >

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 5

Loose Wet

Loose wet avalanche activity may continue on slopes that are exposed to strong solar radiation. Below treeline all aspects are suspect during periods of high freezing levels, the likelihood will increase if we get some rain.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet. >Look for signs of surface instabilities such as pinwheeling and point releasing near cliffs. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wet Slabs

The potential exists for large and destructive wet slabs when the sun is strong and temperatures are high, especially if there was little or no overnight refreeze.

Be aware of the potential for large, deep avalanches.>Avoid rocky, shallow, and/or steep slopes during the heat of the day. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Apr 11th, 2016 2:00PM