Northwest Coastal

Large persistent slabs continue to occur sporadically.

Sticking to conservative terrain is the easiest way to stay safe.

On Sunday, there were several large cornice and storm slabs (size 1.5-2) both natural and explosive triggered on north and west aspects in the alpine.

Last Friday, a failing cornice triggered a size 3 avalanche on an eastern slope in the alpine. This avalanche is believed to have occurred on the March 5th surface hoar layer.

Where a thick, supportive surface crust is found, we expect that triggering avalanches on buried weak layers is unlikely.

Up to 40 cm of recent snow has fallen over various recent crusts which are found up to 1800 m, higher on sunny slopes.

Three layers of note, currently exist in the mid-snowpack:

• A layer of surface hoar and a crust that formed in mid-March is 50 to 80 cm below the snow surface.

• Another layer of surface hoar that formed in early March buried 70 to 120 cm.

• A layer of facets, surface hoar, and/or a crust from mid-February is buried 120 to 200 cm deep.

The remainder of the snowpack is well consolidated.

Monday Night

Mostly cloudy with 0 to 2 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -6 °C.

Tuesday

Mostly cloudy with 0 to 1 cm of snow. 20 to 30 km/h west ridgetop wind. Treeline temperature -5 °C.

Wednesday

A mix of sun and cloud. 10 km/h variable direction ridgetop wind. Treeline temperature -3°C. Freezing level 1400 m.

Thursday

A mix of sun and cloud. 10 km/h southwest ridgetop wind. Treeline temperature 0°C. Freezing level 3000 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 aware of the potential for large, destructive avalanches due to deeply buried weak layers.
• Cornice failures could trigger large and destructive avalanches.
• Avalanche activity is unlikely when a thick melt-freeze crust is present on the snow surface.