South Columbia

Wind effect will drive the avalanche danger in most areas. The safest, and best, riding may be in lower elevation terrain sheltered from the wind.

Moderate - Wind effect is extremely variable

Wednesday: Mainly clear skies / Moderate to strong northerly ridgetop winds / Alpine temperatures of -15Thursday: Clear skies / Light and variable winds / Alpine temperatures of -10Friday: Mainly clear skies / Moderate southwest ridgetop winds / Alpine temperatures of -8

On Monday several naturally triggered wind slab avalanches were observed in mostly treeline and alpine terrain. These avalanches formed in response to new snow and wind on Sunday night and Monday. Continued northerly winds on Tuesday will likely promote a reverse loading pattern increasing the likelihood of human triggered wind slab activity on a variety of aspects.

Up to 30 cm of low density snow fell on Sunday night and Monday. Moderate to strong southwest and then northerly winds have shifted these fresh accumulations into wind slabs in exposed terrain. Recent snow has covered old, thicker wind slabs from previous wind events. The mid-December facet/surface hoar persistent weakness can be found buried 70-120 cm deep and is generally considered dormant. However, we are still receiving occasional reports of sudden results, suggesting that it has to potential to propagate into a large avalanche if triggered, particularly in shallow spots where this layer is closer to the snow surface. The lower snowpack is well bonded and features a thick rain crust near the ground.