Avalanche Forecast
Issued: Jan 7th, 2015 7:45AM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeWarm temperatures and sunshine on Thursday should maintain touchy conditions. Conservative terrain selection is still crucial at this time.
Summary
Confidence
Fair - The weather pattern is stable
Weather Forecast
Synopsis: A strong ridge of high pressure will maintain dry, sunny, and mild conditions for Thursday. An above freezing layer (AFL) is likely between 1500 and 2500 m. Ridge top winds should be light or moderate from the NW. On Friday the AFL should shrink and we might start seeing increasing cloud throughout the day. Theres a chance of flurries on Saturday as the freezing level drops back to valley bottom.
Avalanche Summary
Most areas reported a fairly widespread and large natural avalanche cycle on Tuesday. Many of these slides stepped down to mid-December persistent weak layer and produced avalanches up to Size 3. There were also reports of skiers and machines triggering slab avalanche from a distance (remotely and sympathetically triggered).
Snowpack Summary
30 - 60 cm of snow fell across the region earlier this week with moderate southwest winds shifting these accumulations into deeper deposits in lee terrain. Warm temperatures may keep the storm storm slab sensitive to light triggers. The new snow overlies a variety of old surfaces which include heavily wind-affected surfaces in exposed locations, faceted powder and buried surface hoar in sheltered terrain. Up to 100 cm below the surface, you'll likely find a touchy weak layer of surface hoar sitting on a thick rain crust. This widespread persistent weakness exists at all elevation bands, and continues to be the primary layer of concern for the region. With the recent load of storm snow, I expect this layer to remain active with the potential for large and destructive avalanches. At the base of the snowpack, a crust/facet combo appears to have gone dormant for the time being.
Problems
Storm Slabs
Forecast sunshine and mild temperatures could maintain touchy storm slab conditions and trigger loose wet slides on steep sun-exposed slopes.
The new snow will require several days to settle and stabilize.>Choose conservative lines and watch for clues of instability.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
There is potential to trigger avalanches on a weak layer buried 80-100 cm deep. Be vary wary of slopes that did not slide slide during the last storm and be aware of the potential for triggering slabs from a distance.
Storm slab avalanches in motion have the potential to step down resulting in large and destructive avalanches due to the presence of buried surface hoar.>Stick to simple well supported terrain and be aware of what is above you at all times.>
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 8th, 2015 2:00PM