Avalanche Forecast

Issued: Apr 15th, 2017 4:18PM

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

mgrist, Avalanche Canada

Sea To Sky.

The next big change is on Sunday: Sunny, warm weather will be driving avalanche problems.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Weather Forecast

The clouds will clear out Saturday evening, giving way to pleasant weather on Easter Sunday. Back to wet spring weather on Monday.SUNDAY: Sunshine in the morning, clouding over in the afternoon. Freezing level rising to 1800 m, highs near +3. Winds light southerly.MONDAY: Rain (5-10mm) up to 1600m, with wet snow higher up. Winds 20-30 km/h from the south.TUESDAY: Wet snow or rain. Freezing level around 1500 m. Winds moderate southwesterly.

Avalanche Summary

On Thursday, explosives control work was able to trigger a Size 2 storm slab on a northwest facing aspect in the alpine near Whistler. Skiers were also able to trigger several Size 1 soft slabs in steep leeward alpine terrain. Expect avalanche activity to increase with the warm weather on Sunday.

Snowpack Summary

We've had 20-30 cm of settling storm snow above 1500m. Winds were moderate to strong from a variety of directions and have created fresh wind slabs in exposed terrain at treeline and above. On Sunday the sun will come out in full force - it's a good time to remember that cornices remain large in some areas and could trigger large avalanches when they fail (especially when warmed by the sun). The fatal accident near Lions Bay a week ago illustrates the danger of cornices breaking off, and the large avalanches they can trigger.

Problems

Loose Wet

Warm temperatures and sunshine will make the snow heavy, wet and cohesionless on Sunday. Even small slides can have serious consequences.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Where they exist, cornices pose a significant hazard and should be avoided, especially when the sun comes out in full force.

Falling cornices can trigger large avalanches.Give cornices a wide berth when travelling on or below ridges.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Shifting wind directions have created fresh wind slabs on a variety of aspects.

Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 16th, 2017 2:00PM