South Rockies

Continually assess conditions throughout the day and watch for building wind slabs.

If triggered, wind slabs could step down to deeper layers resulting in very large avalanches.

Large, naturally triggered persistent slab avalanches have been observed recently on north facing slopes. These failed on buried weak layers 1-2 m deep, and some have stepped down to ground. See photos below.

Check out this MIN from our field team.

Moderate

• Uncertainty is due to the extreme variability of wind effect on the snowpack.
• Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Around 15 cm of new snow accompanied by strong southerly wind is expected by Wednesday afternoon. This falls over 50 to 80 cm of wind affected, settling snow that is generally bonding well to the mid December crust.

A prominent crust with 10 cm of facets above is buried 120 to 180 cm deep in terrain above 1800 m. At lower elevations, the mid and lower snowpack is moist to the ground.

Tuesday Night

Mostly cloudy with 4 cm of snow. 20 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 700 m.

Wednesday

Mostly cloudy with 4 to 10 cm of snow. 30 km/h south ridgetop wind. Treeline temperature -5 °C. Freezing level 500 m.

Thursday

Mostly cloudy with 3 to 10 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1400 m.

Friday

Mostly cloudy with 5 to 15 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 800 m.

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.
• Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• Make conservative terrain choices and avoid overhead hazard.