Avalanche Forecast

Observations have been limited in the past few days. We suspect a widespread natural avalanche cycle occurred with the storm on Tuesday.

Last Saturday, a very large (size 4) avalanche was reported on Joffre shoulder. We suspect it failed on a weak layer of facets or surface hoar overlying a crust at the base of the snowpack.

Looking forward to Thursday, backcountry travelers should watch for evidence of wind transport and be cautious in wind-loaded areas.

20 to 40 cm of recent storm snow was accompanied by strong southwest, switching to northwest winds. New snow overlies wind-affected surfaces and a layer of surface hoar in sheltered areas at treeline and below.

A prominent crust varying in thickness is found at treeline and below, 40 to 80 cm down. In some areas, a layer of preserved surface hoar is found just above the crust.

Another weak layer of facets or surface hoar overlying a crust is found at the base of the snowpack down 80 to 120 cm. This is the suspected failure plane for a few large avalanches in the region that occurred on January 6.

Snowpack depths are 100 to 140 cm at treeline and decrease rapidly below.

Wednesday Night

Clear periods with isolated flurries. Alpine winds northwest 15 to 30 km/h. Treeline temperatures drop to -20 C.

Thursday

Mainly sunny with isolated flurries. Northerly winds 20 to 40 km/h. Treeline temperature drops to -25 C.

Friday

Sunny with no new snow. Northerly winds 15 to 30 km/h. Treeline temperature drops to -30 C.

Saturday

Sunny with no new snow. Northerly winds 15 to 30 km/h. Treeline temperatures around -20 C.

More details can be found in the Mountain Weather Forecast.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.