Warm and sunny weather is likely to produce loose snow avalanches, especially on southerly aspects. The danger is rated for the warmest part of the day.
Summary
Confidence
Moderate -
Weather Forecast
WEDNESDAY NIGHT - Mainly clear / east wind, 20-40 km/h / alpine low temperature near 0 / freezing level 1500 mTHURSDAY - Sunny / southeast wind, 10-25 km/h / alpine high temperature near +3 / freezing level 1600 mFRIDAY - Sunny with cloudy periods / light northwest winds / alpine high temperature near +4 / freezing level 1600 mSATURDAY - A mix of sun and cloud /light north winds / alpine high temperature near +4 / freezing level 1600 m
Avalanche Summary
When the sun comes out and temperatures rise during the day, loose wet avalanches will be likely on sun-affected slopes.A few glide slab avalanches up to size 2.5 have been reported near Terrace since Sunday on southerly slopes. Glide slabs typically happen on steep, smooth terrain features such as rock slabs or grassy slopes with little roughness. They are most common on southerly aspects, but during especially warm weather, may occur on shady aspects as well. Slopes with obvious large cracks (glide cracks) as well as slopes with a known history of glide releases are best avoided.
Snowpack Summary
Dry snow remains on shady slopes in the alpine. In these locations, 50-100 cm of well settled snow overlies a layer of weak facets that were buried around March 10th. This is currently the primary layer of concern for human triggering persistent slab avalanches, although recent observations suggest it has become difficult to trigger an avalanche on this layer.Not much further below the March 10th interface is a second weak layer of facets buried on February 19th. Recent loose wet and slab avalanches have been observed gouging into this faceted snow and entraining additional mass.The prolonged warm spell has transitioned sun exposed slopes in the alpine and on all aspects at treeline and below towards becoming isothermal (0 C throughout the snowpack). In these areas spring conditions are in effect; the avalanche hazard will fluctuate greatly depending on the strength of the overnight freeze and how quickly the snowpack is warmed up each day. Check out this guide to managing avalanche hazard during spring conditions HERE.
Problems
Loose Wet
When the sun comes out and temperatures rise during the day, loose wet avalanches will be very likely to occur on sun-affected slopes.
Cornices become weak with daytime heating, travel early on exposed slopes.Avoid sun exposed slopes when the solar radiation is strong, especially if the snow is moist or wet.Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Wet Slabs
Wet slab avalanches are possible on steep, smooth slopes that face the sun.
Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Avoid slopes with a known history of glide avalanches, such as smooth rocky slopes.Avoid slopes with glide cracks.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 28th, 2019 2:00PM
