Avalanche Forecast

Issued: Jan 11th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Expect conditions to change as you gain elevation. Reactive storm slabs may form in higher terrain while rain continues to impact lower elevations. Minimize your exposure to all avalanche terrain during heavy snow or rain.

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

The storm continues, another front moves over the region Wednesday bringing rising temps, snow and wind.

TUESDAY NIGHT: Freezing levels climb to 1600 m overnight, with 15-25 cm expected above. Strong southwest winds. 

WEDNESDAY: 10-20 cm expected over the day. Freezing levels around the Duffy will remain around 1500 m, in the South (Coquihalla/Manning Park areas) they will reach 2500 m by mid afternoon. Strong southwest winds. 

THURSDAY: The front exits leaving clearing skies and no precipitation expected. Freezing levels rise above 2000m, with light easterly winds. 

FRIDAY: A mix of sun and cloud with strong southwesterlies. Freezing levels ranging from 1500-1900 m. 

Avalanche Summary

The incoming storm is expected to create storm slabs that are reactive to human triggers at high elevations. Low elevations will see rain on snow and rising temperatures, creating likely conditions for wet loose avalanches.

Over the last few days natural avalanche activity has been observed in the highway corridors to size 2.5 in below treeline features. 

Snowpack Summary

20-40 cm of mixed precipitation has created a variety of surface snow conditions. Alpine areas have seen strong southwest winds creating deeper deposits in north through east facing slopes. At lower elevations the precipitation fell as rain creating a saturated upper snowpack. 

This recent precipitation adds to the 50+ cm of snow that has fallen since January 1, which may overly sugary faceted grains that formed during the cold spell in late December.

Around 80 to 200 cm deep, a weak layer of faceted grains may be found above a melt-freeze crust that formed in early December. The layer is most prominent between 1700 and 2100 m. Observed avalanches on this layer are sporadic and isolated. The most likely place to trigger it would be in thin, rocky snowpack areas. The lower snowpack is well-settled and strong.

Terrain and Travel

  • Use increased caution at all elevations. Storm snow is forming touchy slabs.
  • Be alert to conditions that change with elevation and wind exposure.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Fresh storm slabs will form with new snow above 1500m and warm temperatures. Greater loading will be found in wind loaded features, from strong southwest winds. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Wet

An icon showing Loose Wet

Expect loose wet avalanches below 1700m as rain continues to saturate the surface snow. Be prepared to change your travel plans if you encounter wet and heavy surface snow.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Jan 12th, 2022 4:00PM