10 to 25 cm of snow accompanied by southwest wind is expected Monday night. This snow adds to the existing wind stiffened storm slab that rests on a crust. If overnight snow totals exceed 20 cm in your local area, the Alpine danger may be "High."
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Continued precipitation is expected through Monday night before a brief lull in the action Tuesday and Wednesday. Thursday's system has potential to be juicy, but there is a lot of discrepancy surrounding how much precipitation it will deliver. Stay tuned for details. MONDAY NIGHT: Overcast, freezing level around 1000 m, moderate southwest wind, 10 to 25 cm of snow.TUESDAY: Overcast, freezing level around 1000 m lowering through the day, light southwest wind, 5 to 10 cm of snow expected.WEDNESDAY: Overcast, freezing level around 500 m, light scattered wind, trace of snow possible. Up to 30 cm possible Wednesday night.THURSDAY: Overcast, freezing level may rise as high as 750 m, strong west wind, 10 to 30 cm of snow possible.
Avalanche Summary
On Monday control work produced avalanches to size 2 with crowns averaging 20 cm in depth. On Sunday ski cutting in the alpine triggered small avalanches in steep lee terrain.
Snowpack Summary
15 to 35 cm of new snow sits on a crust that formed Saturday. About 20 cm of moist snow can be found below the crust. The new snow was redistributed by moderate to strong southeast through southwest winds on Sunday. Up to 100 cm below the surface there is a widespread melt-freeze crust that was buried on December 15th. This layer has not produced much in the way of avalanche activity and is likely trending towards dormancy. Beneath the mid-December crust, the lower snowpack is generally strong and well settled.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.