Avalanche Forecast

Moderate - Freezing levels are uncertain on Tuesday

The ridge that setup the recent inversion will shift east as an offshore front makes landfall with the south coast Tuesday morning. The interior ranges will remain mostly dry with only some light precipitation on Tuesday. A stronger Pacific storm will hit the south coast on Wednesday morning with precipitation spilling into the interior on Wednesday afternoon. Light snowfall is expected to continue through Thursday. TUESDAY: Increasing cloud cover, freezing level initially at valley bottom rising to around 1500 m in the afternoon. Strong southwest wind, trace of snow possible in the afternoon, 1 to 5 cm possible Tuesday night.WEDNESDAY: Broken cloud cover, freezing level around 1500 m, moderate to strong south/southwest wind, 2 to 8 cm of snow possible. THURSDAY: Broken cloud cover, freezing level around 1500 m, moderate to strong southwest wind, trace of snow possible.

On Sunday loose avalanches were reported from all aspects to size 1.0. On Southwest, south and southeast facing terrain between 1500 m and 2700 m, loose wet avalanches to size 2.5 and persistent slab avalanches to size 2.0 were reported to have failed naturally. A small wind slab was human triggered on a north facing feature just below ridge crest. On Saturday natural avalanches up to size 2.5 were reported on northeast facing features between 1200 m and 1500 m. One small skier triggered avalanche was remotely triggered on a moderately inclined northeast facing alpine feature. Reports from the last few days include several size 1 to 1.5 persistent slab avalanches that were triggered remotely (from a distance) with slabs 30 to 100 cm in depth. Both the early January and mid-December surface hoar layers were noted as failure planes. These reports all came from the south of the region.

A breakable melt freeze crust is beginning to form on the surface at and above treeline.The last series of storms left 20 to 50 cm of snow in their wake with more snow falling in the south of the region. This snowpack is currently quite complex, and there are three active Persistent Weak Layers (PWL) that we are monitoring. The first PWL is known as the early January interface, it is 20 to 50 cm below the surface. It is composed of surface hoar on sheltered slopes as well as sun crust on steep solar aspects. It is thought to be widespread at all elevations bands and has produced numerous recent large avalanches. The next PWL is the mid-December facet/surface hoar/crust combination which is now buried 50 to 80 cm deep and is most problematic at and below treeline. This interface is not thought to be present in the alpine.The most deeply buried PWL is the late November rain crust. It is down 70 to 100 cm below the surface and has been less reactive in recent snowpack tests but it may still be susceptible to human triggering, especially in alpine terrain features with a thin or widely variable snowpack.