Avalanche Forecast

Issued: Apr 9th, 2016 3:00PM

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

pmarshall, Avalanche Canada

South Columbia.

Spring conditions. Avalanche danger is expected to rise during the day with warming and solar radiation. Plan to retreat to cooler north-facing terrain if the snow surface is becoming moist or wet.

Summary

Confidence

High

Weather Forecast

SUNDAY: Mainly sunny. The freezing level dips to 2000 m overnight but shoots up to 2500 m in the afternoon. Winds are light and variable. MONDAY: Increasing cloud. The freezing level remains near 2600 m and winds are light. TUESDAY: Cloudy with possible showers or flurries. The freezing level is around 2400-2500 m. Winds could increase to moderate from the SW.

Avalanche Summary

Several natural and rider triggered loose wet slides to size 1.5 were reported on Friday, while a more widespread but small (size 1-1.5) natural loose wet avalanche cycle was observed on steep solar aspects on Thursday. There were also a few reports of isolated slabs up to size 2 from north-facing alpine slopes. The possibility of persistent slabs and cornice falls should increase if the snowpack does not refreeze overnight and temperatures remain high.

Snowpack Summary

The snow surface is currently going through a typical spring melt-freeze cycle on all aspects and at all elevations, except possibly high true-north slopes which could be holding onto cold snow. A moist/wet, isothermal, and rapidly melting snowpack exists on all aspects below around 1500 m and probably even higher on solar aspects. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on. The late February persistent weak layer is down 80 to 120 cm below the surface. This layer may be a concern in isolated terrain, but it will probably take a large trigger like a cornice fall or surface avalanche in motion to set it off.

Problems

Loose Wet

Loose wet activity should continue, particularly on solar aspects during the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Cornices could fail easily during the day when temperatures soar and the sun reappears.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

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.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Apr 10th, 2016 2:00PM