Avalanche Forecast

Issued: Apr 25th, 2022 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 Cornices.

Chris Gooliaff,

Glacier.

Monday's midnight moisture might make moving messy below Treeline, while winter weather and wind slabs whiten the wilderness above.

Start and finish early to maximize your travel time on solid surface crusts.

Summary

Weather Forecast

Snow/rain tonight will prevent a solid crust recovery below treeline, with freezing levels (FZL) hovering near 1800m. Unsettled wx through Thurs

Tonight: Rain/Snow, 15cm, Alpine low -4*C, FZL 1800m, mod SW wind

Tues: Flurries with sun/cloud, trace amounts, Alp high -3*C, FZL 1800m, light W wind

Wed: Sun/cloud, Alp high -5*C, FZL 1500m, light SW winds

Snowpack Summary

There are 2 snowpacks in the region at the moment. Below 2000m exists a firm Spring-time melt-freeze snowpack that is solid in the am, then breaking down with daytime warming. Above 2000m, a winter snowpack dominates, with several crusts in the upper pack, wind slabs on lee Alpine features, and dry powder on high, sheltered, N'ly slopes.

Avalanche Summary

Strong solar input and warm temps caused a loose wet cycle to size 2.5 this weekend. On Friday a notable size 3 slab avalanche from Avalanche Crest was observed at Treeline, W aspect (suspected to be windslab on the April 18th crust).

The warmth over the weekend also helped several glide slabs to avalanche.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Loose Wet

Minimal crust recovery Sunday night coupled with moderate to heavy rainfall Monday evening may create isothermal conditions below 2000m. Watch for moist/wet avalanches, especially on steeper slopes, until cooler weather locks it back up.

Use extra caution on slopes if the snow is moist or wet.
Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Wind Slabs

Pockets of wind slab, up to 30cm deep, sit on a crust on all but high N'ly slopes, where they are perched atop previous variable slabs. Incoming moisture and wind overnight will create new slabs in lee features Treeline and above.

Recent snow may be more sensitive to human triggering on solar aspects where it sits on sun crust
Use caution on steep lee and cross-loaded slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Cornices

Large cornices are reaching their "Best Before" date, meaning they are calving off under their weight and the added stress of warmer weather. Limit your exposure below them and expect they'll be fragile while traveling along ridge crests.

Give cornices a wide berth when traveling on ridges.
Avoid travel on slopes that are exposed to cornices overhead.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Apr 26th, 2022 4:00PM