Avalanche Forecast

Issued: Apr 20th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada mconlan, Avalanche Canada

Assess for wind slabs in steep terrain.

Summary

Confidence

High - The snowpack structure is generally well understood.

Weather Forecast

WEDNESDAY NIGHT: Increasing clouds with trace snowfall, 10 km/h southeast wind, alpine temperature -7 C.

THURSDAY: Cloudy with snowfall, accumulation 2 to 5 cm, 10 km/h southwest wind, alpine temperature -4 C, freezing level rising to 1800 m.

FRIDAY: Cloudy with snowfall, accumulation 2 to 10 cm, 10 km/h southwest wind, alpine temperature -2 C, overnight freeze and daytime freezing level rising to 2000 m.

SATURDAY: Mix of sun and cloud with trace snowfall, 10 km/h northwest wind, alpine temperature -1 C, overnight freeze and daytime freezing level rising to 2200 m.

Avalanche Summary

Small wind slabs were triggered in lee terrain features on Tuesday. Storm slabs were triggered in the west of the region where up to 30 cm of snow accumulated. They were small to large (size 1 to 2), 10 to 30 cm deep, and between 2000 and 2500 m.

Please consider posting your observations to the Mountain Information Network to supplement our data stream and help fellow recreationists.

Snowpack Summary

Light amounts of snow will accumulate on Wednesday. It will build on the 10 to 15 cm from Tuesday for most areas, with localized amounts up to 30 cm in the west of the region. Wind slabs may be found in lee terrain features from strong southwest wind. All this snow overlies consolidated faceted snow over a hard melt-freeze crust. Below treeline, a consolidated, moist snowpack exists. At ridge top, remember that cornices are large and looming at this time of year.

Around 100 to 200 cm deep, faceted grains persist around a hard melt-freeze crust from early December. There's uncertainty on if and when this layer will wake up, but it could during the next intense or prolonged warm-up.

Terrain and Travel

  • Carefully evaluate steep lines for wind slabs.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Use caution entering steep, lee terrain features below ridges, where wind slabs could be found. The snow could slide easily where it rests on faceted grains or a hard melt-freeze crust.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 21st, 2022 4:00PM