Avalanche Forecast

Moderate - Intensity of incoming weather systems is uncertain

TUESDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind moderate, southwest. Temperature near 0. Freezing level 1500 m. Weak alpine inversion.WEDNESDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind moderate to strong, south. Temperature -2. Freezing level 1600 m.THURSDAY: Snow. Accumulation 10-20 cm. Ridge wind moderate to strong, southwest. Temperature near 0. Freezing level 1600 m.

Sunday there were reports of natural loose wet avalanches to size 2.5 on solar aspects as well a size 3 deep-persistent, slab avalanche on a northerly aspect that's suspected to have failed on the December 15th layer.Very significant avalanche activity occurred in the region last Wednesday and Thursday. A smaller avalanche cycle, mostly affecting the recent storm snow was reported on Saturday. As temperatures warm lower elevations that have so far remained cool during the inversion, there is still an increased likelihood of triggering something large.

Warm alpine temperatures have made the snow surface moist on slopes that face the sun. Below the surface, 40 to 60 cm of recent snow has settling into a cohesive slab on top of the reactive January 5th interface which consists of a crust/surface hoar combination on steep southerly aspects and pure surface hoar on remaining aspects. The late December surface hoar also remains reactive and is now down 80 to 90 cm below the surface. Adding to the complexity of the mid to upper snowpack is the mid-December surface hoar which is now 100 to 130 cm below the surface. This spooky interface continues to produce sudden snowpack test results and is most pronounced at treeline, but is also present below treeline. The overlying slab is now deep, dense and destructive. Two laminated crusts created by rain events in late November lay just below the mid-December interface, and may co-exist with facets. In shallow, rocky terrain the mid-December surface hoar and the late November crust seem to be reacting together which is a volatile combination.