South Columbia

Conditions are generally safe, but there are still isolated hazards from cornices and pocket wind slabs. Check out the newest forecaster blog as you plan your spring objectives.

A few large cornice failures (size 2) were reported on Monday and Tuesday, and a skier-triggered size 3 cornice reported Wednesday in Rogers Pass. There were also a few small (size 1) human-triggered wind slab avalanches in alpine terrain (see photos of this remotely-triggered wind slab from Wednesday).

FRIDAY NIGHT: Cloudy with starry breaks and isolated flurries, trace to 5 cm, light northeast wind, treeline temperatures dropping to -15 C.

SATURDAY: Mostly sunny, light wind from the northeast, freezing level rising to 1500 m, treeline temperatures warm to -3 C.

SUNDAY: Sunny, increasing southwest wind, freezing level rising to 1500m, treeline temperatures warm to 0 C.

MONDAY: Mix of sun and cloud and incoming flurries, increasing southeast wind, freezing level rising above 1600 m, treeline temperatures above freezing.

At treeline and above up to 20 cm consolidated and wind-affected snow covers a crust on all aspects to 2200 m and up to mountain tops on solar aspects. Recent northeast wind has formed wind slabs on lee aspects below ridgetops and left a variety of wind affected surfaces. Another prominent crust layer is found 40-80 cm deep. Cornices are very large and exposure to slopes beneath them should be minimized, especially if the weather is sunny, warm, or windy.

• Pay attention to cornices and give them a wide berth when traveling on or below ridges.
• Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
• Back off slopes as the surface becomes moist or wet with rising temperatures.