North Rockies

Pay attention to the wind and how the snow feels. Recent wind slabs have been most reactive where they overlie a thin crust.

SUNDAY NIGHT: Cooling temperatures, increasing cloud, and isolated flurries, 5 cm. Gusty moderate west-northwest wind. Ridgetop low temperatures below -3 C as freezing level descends to valley bottom.

MONDAY: Clearing with sunny breaks in the afternoon. Moderate west wind, daytime high temperatures below -2 C, and freezing level reaching 800 m before returning to valley bottom.

TUESDAY: Mix of sun and cloud. Gusty increasingly strong west wind. High temperature -4 C. Freezing level at valley bottom, possible inversion.

WEDNESDAY: Sunny breaks with increasing cloud. Moderate west wind. High temperature -4 C.

On Saturday, wind slab avalanches to size 1.5 were reactive to riders and explosives triggered avalanches to size 2, avalanches were 20-40 cm deep and found in lee areas from westerly winds.

Small (size 1-1.5) storm slab and loose dry avalanches avalanches were reported late Thursday with new snow and wind, particularly where more than 30 cm of snow accumulated and wind exceeded 25 km / hr.

Winds have stiffened 20-35 cm recent snow in open areas at treeline and throughout the alpine. Gusty winds may have loaded terrain further downslope than usual. Cool overnight temperatures have produced a surface crust up to 1500 m and on steep solar slopes. 

The recent snow covered a thin crust up to 1650 m, this was the suspected surface in recent wind slab avalanches. Another crust is found down 70 cm, but has not shown recent reactivity. The lower snowpack is generally strong and bonded, with one or multiple crusts near the ground. We suspect the lower snowpack could be weak in shallow rocky wind-affected slopes east of the divide.

• Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
• Wind slabs may be poorly bonded to the underlying crust.
• Carefully evaluate steep lines for wind slabs.