Avalanche Forecast

Issued: Apr 9th, 2016 8:02AM

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

Purcells.

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 1000 m overnight but shoots up to 2300 m in the afternoon. Winds are light and variable. MONDAY: Sunny in the morning with increasing cloud late in the day. The freezing level remains near 2500 m and winds are light. TUESDAY: Cloudy with possible showers or flurries. The freezing level is around 2500 m. Winds could increase to moderate from the SW.

Avalanche Summary

There are very few reports trickling in at this time of year. One observer did report a few size 3 slabs from solar aspects that likely occurred on Thursday or Friday. Loose wet activity to size 2 was also reported. The possibility of wet slabs and cornice falls will 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. A few lingering persistent weak layers still exist in the upper snowpack (50-130 cm deep). There has been no recent reported activity on any of these layers, but there is potential for wet slabs to release on one of these layers, or near the ground, when it's sunny and hot.

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.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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.

Do your best to avoid traveling on or underneath cornices. If you have to, move quickly and only expose one person at a time.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Wet Slabs

Intense solar radiation, a heavy wet surface sluff, or a cornice fall could be enough to trigger a wet destructive slab failing on lurking deep weaknesses.

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