Archived

Avalanche Forecast

Apr 3rd, 2017–Apr 4th, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Lizard-Flathead.

The sun will be out in force on Tuesday. As it rapidly warms the snowpack, there will be an increasing likelihood of avalanches.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

TUESDAY: Sunny, moderate southwest wind, freezing level up to 2000 m after an overnight freeze.WEDNESDAY: Mix of sun and cloud, strong west wind, freezing level climbing to 2200 m with little overnight freeze.THURSDAY: Mostly cloudy with snow/rain starting later in the day, moderate southwest wind, freezing level holding at 2200 m.

Avalanche Summary

Several natural and skier triggered size 1-1.5 loose wet avalanches were reported on Monday. On Sunday, a few small storm slabs were triggered by explosive avalanche control and ski cutting and a size 2 slab was triggered by a natural cornice fall.On Tuesday, storm slabs may still be reactive at higher elevations. Warm sunny weather will also increase the possibility of loose wet avalanches and cornice falls.

Snowpack Summary

Daytime warming will create moist surfaces, especially on southerly aspects. 10-20 cm of recent dry snow can be found on northerly aspects above 1700 m. Elsewhere the surface snow is experiencing a daily melt-freeze cycle, forming thick supportive crusts overnight and moist snow during the day. The December facets and November rain crust are buried deep, and did not become reactive during the latest period of warm weather, rain, and strong solar radiation.

Avalanche Problems

Storm Slabs

Storm slabs may still be reactive on steep convexities and on wind loaded terrain features at higher elevations where the snow is still dry.

Use caution in lee areas. Wind loading could create slabs.Use caution on open slopes and convex rolls Be alert to conditions that change with elevation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

Solar triggered loose wet avalanches should be expected from steep sun exposed slopes during the heat of the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Cornices are large and may fall off naturally during periods of sun or from daytime warming.

Cornices become weak with daytime heating, so travel early on exposed slopes.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 2