Avalanche Forecast

Issued: Apr 2nd, 2021 4:00PM

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

Garth Lemke,

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Be vigilant for windslabs building with small inputs of snow and steady SW winds. The freezing level is incrementally rising the next few days. Expect precipitation in the form of rain at lower elevations that can rapidly destabilize the snow.

Summary

Weather Forecast

Saturday will bring 12 cm mostly late in the day, -3C, light gusting strong SW winds, and 1800m freezing level. Sunday will be flurries, 4cm of snow, -5C, light to moderate West winds, and 1500m freezing level. Monday will be warmer with a 1900m freezing level.

Snowpack Summary

Widespread variability on the surface with 10cm of new snow and variable winds forming wind slabs on a variety of aspects at TL and ALP. Deteriorating travel conditions below 1900m. The snowpack shows strength and good bonding in field tests but "feels" weak in shallow snowpack regions like Whistlers/Portal creek and Maligne zones.

Avalanche Summary

Use the Mountain Information Network to report your field observations and contribute to the bulletin. Friday's Icefield patrol noted no new natural but the visibility was poor. From the vantage point on top of Whistler mountain also noted no new activity but visibility was very poor. 

Confidence

Freezing levels are uncertain on Saturday

Problems

Loose Wet

An icon showing Loose Wet

The incoming 10mm of precipitation will likely be rain at low elevations. This has the potential to activate this problem by soaking the shallow snowpack. 

  • Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs

New and building wind slab can be found in all lee features near ridge crests, and cross-loaded gullies. Previous reverse loading occurred early this week from uncharacteristic North winds.

  • Be alert to conditions that change with elevation.
  • Be careful with wind loaded pockets, especially in steep confined alpine terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

When in the Whistlers/Portal and Maligne Regions identify and assess the bond at this mid-pack layer. This interface shows strength in field tests, but there is concern for wide, spatial variability over large and/or connected features.

  • If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
  • Be alert to conditions that change with elevation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Apr 3rd, 2021 4:00PM