Avalanche Forecast

Issued: Apr 18th, 2023 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs and Deep Persistent Slabs.

Avalanche Canada lbaker, Avalanche Canada

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Dial back your terrain choices where you are finding more than 20 cm of new snow. Avoid wind loaded areas where slabs are deeper, more cohesive, and are likely reactive to human triggering.

Summary

Confidence

Low

Avalanche Summary

No new avalanches were reported in this region on Monday.

We expect backcountry users will see evidence of a large avalanche cycle from last week's rain event when numerous wet loose avalanches reached the valley bottom.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

In the alpine and around treeline, 20-40 cm of snow covers a frozen crust.

The mid snowpack is generally settled and strong, except in areas with snow depths less than 150 cm. In these lower snow areas, the mid-pack is likely weaker and more faceted.

The lower snowpack includes a layer of large, weak facets and/or depth hoar crystals.

Below treeline, expect to find moist or refrozen surfaces, and a shrinking snowpack that is isothermal during the heat of the day.

Weather Summary

Tuesday Night

Cloudy with scattered flurries. 3-9 cm of snow is expected in the alpine. Light northerly ridgetop wind. Freezing levels fall to 1000 m. Treeline high around -5 °C

Wednesday

The Elkford region is forecast to be cloudy with scattered flurries, 10-20 cm of new snow in the alpine.

In the Purcells and Bull area, 2-3 cm of new snow is forecast.

Both regions will see light northwest ridgetop wind. Freezing levels of 1500 m and treeline highs around -1 °C.

Thursday

Mainly cloudy with sunny periods and isolated flurries, trace accumulations. Light west ridgetop wind. Freezing level at 1700 m. Treeline high around -1 °C.

Friday

Mainly sunny with cloudy periods. Light southwest ridgetop wind. Freezing level at 2000 m. Treeline high around 0 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Be carefull around freshly wind loaded features.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

The Elkford area is forecast to get the highest snowfall amounts with up to 20 cm.

Strom slabs will be reactive in areas that receive higher snowfall amounts and on steep, wind exposed slopes where new snow is more likely to form a cohesive slab. Use caution around leeward terrain features where deposits are deep.

In southerly facing terrain expect new snow to overlay a melt freeze crust, providing an ideal sliding surface for storm slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The base of the snowpack remains weak. Avoid thin, rocky start zones and shallow areas with variable snowpack depths.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 19th, 2023 4:00PM

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