Avalanche Forecast

Moderate - Due to the number of field observations

Light snowfall (2-3cm) is expected on Tuesday and early Wednesday. Clouds are expected to scatter throughout the day on Wednesday, while clear skies are forecast for Thursday. Ridgetop winds are expected to be generally light to moderate and southwesterly on Tuesday, switching to northwesterly by Wednesday. Daytime freezing levels should hover around 1200m for the forecast period.

A natural wind slab avalanche cycle to size 2.5 was observed in mostly northeast facing alpine terrain on Sunday. The activity occurred in response to new snow and strong southwest winds on Saturday night. A size 2 persistent slab avalanche was also noted on Sunday in the Dogtooth Range. The avalanche, which failed on a northeast aspect at 2200m, started as a smaller wind slab and stepped-down to the late February layer. On Monday, explosives control triggered another size 2 persistent slab avalanche on a north facing alpine slope.

On Saturday night, 8-15cm of new snow fell. Strong southwest winds redistributed these accumulations into touchy wind slabs at treeline and in the alpine. 35-70 cm below the surface you'll find a persistent weak layer comprised of surface hoar, facets and/or a thick crust. This layer, which was buried on February 27th, seems variably reactive. In other words, it's still really touchy in some places while in other places it's really tough to trigger, and there's not much of a reliable pattern telling us what exact aspects are most suspect. I'd continue to be suspicious of steep, unsupported features at treeline and in the alpine as this layer has the potential for large avalanches. Deeper weak layers from mid-February and early January are now down 50-90cm and 70-120cm respectively. Triggering an avalanche on either of these layers has become unlikely but either still has the isolated potential to produce very large avalanches with a heavy trigger or significant warming.