Avalanche Forecast

Issued: Apr 19th, 2022 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

Use caution entering steep terrain features, as new wind slabs may have formed.

Summary

Confidence

High - The snowpack structure is generally well understood.

Weather Forecast

TUESDAY NIGHT: Partly cloudy with no precipitation, 10 km/h west wind, alpine temperature -8 C.

WEDNESDAY: Mix of sun and cloud with no precipitation, 10 km/h southwest wind, alpine temperature -5 C, freezing level rising to 1800 m.

THURSDAY: Cloudy with snowfall, accumulation 5 cm, 10 km/h south wind, alpine temperature -3 C, overnight freeze and daytime freezing level rising to 2000 m.

FRIDAY: mix of sun and cloud with isolated flurries, accumulation 2 to 5 cm, 10 km/h west wind, alpine temperature -2 C, overnight freeze and daytime freezing level rising to 2100 m.

Avalanche Summary

Cornices up to size 3 were triggered by explosives on Monday, with some of them triggering slabs on slopes below.

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

Snowpack Summary

Around 10 to 15 cm of snow accumulated on Tuesday in most of the region, with locally higher amounts up to 30 cm in the west. The snow fell with strong southwest wind, which may have formed new wind slabs in lee terrain features at treeline and alpine elevations. The snow fell onto consolidated faceted snow over a hard melt-freeze crust. A moist, consolidated snowpack exists at low elevations below treeline. 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

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • 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.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Problems

Wind Slabs

An icon showing Wind Slabs

Small wind slabs may have formed from recent snow and strong southwest wind. Use caution entering steep, lee terrain features below ridges. Resulting slabs could slide easily, as they rest on faceted grains or a hard melt-freeze crust.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 20th, 2022 4:00PM