Avalanche Forecast
Issued: Mar 14th, 2013 10:46AM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
Thursday night and Friday: Freezing levels will start to drop (1500 m.) bringing the snow line lower. Moderate amounts are expected until Friday and will taper off becoming light during the day. Moderate to strong winds should switch from the SW to the W.Saturday: Unsettled conditions without any frontal systems bringing very light precipitation, strong W winds, mainly cloudy skies and freezing levels near 1000 m.Sunday: Similar pattern as Saturday with cooler temperatures and lighter winds.
Avalanche Summary
I suspect that a natural avalanche cycle is ongoing in the region. Slab avalanches up to size 3 have been reported out of alpine features especially on N-NW-NE aspects. Loose avalanches were also reported up to size 1.5 in the recent snow.Â
Snowpack Summary
The warm storm has left from 20 to 45 cm of snow above 2000 m.. At higher elevations, snow has been transported by strong SW and W winds creating windslabs that are very touchy. Below the freezing line, the snowpack is rain soaked. Another pulse of precipitation will add weight onto the storm slab and the already moist/wet snowpack. The new snow has not been bonding well to the underlying surfaces creating lots of recent avalanche activity, easy snowpack test results and reactivity to skier traffic. Some of the significant underlying surfaces mentioned before include a surface hoar layer in shaded-sheltered areas, a suncrust on S aspects and a melt-freeze crust below 1700 m. The surface hoar persistent weak layer buried down 100 cm is also still a concern to professionals and would generate very large avalanches if triggered.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 15th, 2013 2:00PM