Avalanche Forecast

Issued: Apr 16th, 2017 4:17PM

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

mgrist, Avalanche Canada

Sea To Sky.

Wind slabs and cornices are the main concerns right now. Carefully assess terrain before committing to bigger lines.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Tuesday

Weather Forecast

We're back to wet spring weather on Monday, and continuing throughout the forecast period. MONDAY: Rain (5-10mm) falling mostly after noon, with wet snow (5-10cm) above 1500m. Winds 20-30 km/h from the south.TUESDAY: Wet snow or rain (10-20mm / cm). Freezing level around 1500 m. Winds moderate southwesterly.WEDNESDAY: Rain (10-15mm) up to 1600m. Winds strong southerly.

Avalanche Summary

On Sunday, skiers were able to trigger Size 1 wind slabs near Whistler, running in recent storm snow. Small, loose wet avalanches were also reported during the heat of the day on Sunday.

Snowpack Summary

We've had 20-30 cm of settling storm snow above 1500m. Warm temperatures on Sunday (+4 at treeline) likely resulted in a melt-freeze crust on all aspects and elevations at treeline and below. Lingering wind slabs may still exist in exposed terrain features at treeline and above. Cornices remain large in some areas and could trigger large avalanches when they fail. The fatal accident near Lions Bay a week ago illustrates the danger of cornices breaking off, and the large avalanches they can trigger.

Problems

Wind Slabs

Isolated wind slabs may still be lingering in the alpine and exposed treeline features.

Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Cornices

Where they exist, cornices pose a significant hazard and should be avoided.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

If the snow does not experience an overnight re-freeze, there is an increased risk of loose wet avalanches. Even small slides can have serious consequences.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 17th, 2017 2:00PM