Avalanche Forecast

Issued: Mar 31st, 2024 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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While the best riding conditions may be found on north facing, alpine slopes - persistent weak layers may still be reactive here.

Watch for changing surface conditions on sunny slopes.

Summary

Confidence

Moderate

Avalanche Summary

On Thursday, a size 1 rider triggered slab was reported. While the slab was only 10 cm deep, this shows the potential of small avalanches in steep or unsupported terrain features.

We are still awaiting observations but expect a loose wet avalanche cycle to have occurred during the rapid warm up on Sunday, and to continue on Monday. There is also potential for the persistent slab problem to reactivate in the warm temperatures.

Snowpack Summary

Around 5 cm of moist or wet surface snow sits over a widespread crust. On steep south facing slopes the crust below may also break down in the warm temperatures.

The facet/crust layer that produced large avalanches during early March is buried 80-150 cm deep. While no recent avalanche activity has been observed on this layer, it continues to produce concerning snowpack test results. It has become a low-probability, high-consequence problem on north-facing slopes above 2000 m. It is uncertain how this layer will react to rising temperatures.

Weather Summary

Sunday night

Partly cloudy. 10 to 20 km/h southwest ridgetop wind. Freezing level 2500 m. Treeline temperature 0 °C.

Monday

A mix of sun and cloud. 10 to 20 km/h suthwest ridgetop wind. Freezing level 2500 m. Treeline temperatures near +2 °C.

Tuesday

Freezing levels remain above 2000 m overnight and throughout Tuesday. A mix of sun and cloud with flurries starting in the afternoon, around 5 cm. 40 to 50 km/h southwest ridgetop wind. Treeline temperature +2 °C.

Wednesday

Overnight freezing level drops below 1000 m. 5-15 cm of new snow overnight then clearing to a mix of sun and cloud. 20 to 30 km/h southwest ridgetop wind. Freezing level 1300 m. Treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Problems

Loose Wet

An icon showing Loose Wet

Potential for wet avalanche activity (slab and loose) increases as temperatures rise, but concern is greatest on steep, sun affected slopes. Avalanches may initiate easily on the smooth crust below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs

Concern remains for human-triggering a persistent weak layer on sheltered north aspects above 2000 m. If triggered, avalanches will be large and destructive. Avoid shallow snowpack areas where triggering is more likely.

Aspects: North, North East, North West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 1st, 2024 4:00PM

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