Avalanche Forecast

Issued: Apr 1st, 2016 9:24AM

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

rbuhler, Avalanche Canada

Sea To Sky.

Hazard is expected to slowly drop with the cooling over the weekend but avalanche problems are expected to linger for a while longer. Extra caution is required around and below cornices, and on steep sun exposed slopes during the heat of the day.

Summary

Confidence

Moderate

Weather Forecast

A mix of sun and cloud is expected for Saturday with freezing levels dropping to around 2000m and moderate westerly winds in the alpine. Mostly cloudy conditions are forecast for Sunday with light southwest winds in the alpine and afternoon freezing levels around 2000m. A storm system is forecast to reach the south coast on Sunday evening. 15-20mm of precipitation is expected by Monday evening. Freezing levels are forecast to start around 2000m at the beginning of the storm and drop to around 1500m by the end of the storm on Monday.

Avalanche Summary

On Thursday, loose wet sluffing up to size 2 was reported throughout the region. A couple cornice releases were also observed but no slab avalanches were reported. On Wednesday, a natural size 2 was reported on a south aspect at 2000m. Skiers triggered a size 1.5 avalanche on a south aspect at 2200m. These avalanches were 10-40cm deep with the most recent snow sliding on a crust. Loose wet avalanches up to size 2.5 and cornice releases up to size 3 were also reported. Cooling temperatures on Saturday will mean that natural sluffing and cornice releases will become less likely, but with all the heat in the snowpack, it will still be possible for human-triggering of cornices and sluffing. These problems are expected to linger until the region gets a substantial refreeze and a widespread crust forms on the snow surface.

Snowpack Summary

A moist/wet snow surface is reported to be widespread to mountaintops except for shaded true north aspects above 2600m. The last few nights have seen some limited overnight crust formation which has quickly broken down the following morning. With freezing levels dropping on Saturday, a surface crust is expected to form at higher elevations and not completely break down during the day. Large cornices are lingering and are expected to remain weak until there is a substantial period of cooling. Below the snow surface, the mid snowpack is generally well-settled throughout with no notable persistent weaknesses.

Problems

Cornices

Large cornices may become weak with afternoon warming and sun exposure. They can be destructive by themselves, and may also become the trigger for a slab avalanche on the slope below.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Loose Wet

Loose wet sluffing is possible on sun exposed slopes during the heat of the afternoon. Very warm conditions may increase the size and run length of natural sluffing.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet. >Be cautious of sluffing in steep terrain. >

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 2nd, 2016 2:00PM