Avalanche Forecast

Archived

Mar 21st, 2020–Mar 22nd, 2020

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

South Columbia.

A low pressure system is due to move in by late afternoon. Clouds, cooler temperatures, and snow are on the way. Low hazard doesn't mean no hazard. Make observations and assess conditions continually.

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

Saturday night: Mostly clear, light west wind, alpine temperature -11 C, freezing level valley bottom.

Sunday: Increasing cloud, light southwest wind, alpine temperature -6 C, freezing level 1500 m.

Monday: Cloudy, 5-10 cm of snow, light southwest wind with moderate gusts, alpine temperature -6 C, freezing level 1400 m.

Tuesday: Mostly cloudy, 5-10 cm of snow, light southwest wind, alpine temperature -7 C, freezing level 1300 m.

Avalanche Summary

Over the past several days, avalanche activity was reported as natural loose wet avalanches (size 1-2) running in steep, sun-exposed terrain. Cornices were also observed failing naturally, primarily on north, northeast, and east aspects.

Avalanches releasing on the late February surface hoar layer were most recently reported on Monday. These avalanches occurred on a variety of aspects between 1700 m and 2300 m and were breaking 40-100 cm deep.

If you decide to travel in the backcountry, consider sharing your observations via the Mountain Information Network (MIN) to supplement our data stream as operators are shutting down. A conservative mindset and margins are recommended at this time.

Snowpack Summary

With snow on the way, Sunday's surface conditions will comprise the next interface. Recent reports indicate that surface conditions are highly variable with a mix of sun crusts, moist snow, hard wind slabs, and soft faceted snow. Observers have noted that surface hoar may be forming on sheltered, shady slopes. These conditions will be important to track across aspects and elevations if you're spending time in the mountains on Sunday.

Cornices are large, looming, and weakening with warm temperatures and strong solar radiation.

A widespread weak layer of surface hoar from late February is buried 60-120 cm deep. Sheltered north, northeast, and east facing slopes near treeline are the most likely locations to find this layer. Though there is a low likelihood of triggering an avalanche on this layer, the consequences of doing so would be high.

Terrain and Travel

Back off slopes as the surface becomes moist or wet with rising temperatures.
Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
Make observations and assess conditions continually as you travel.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.