Avalanche Forecast
Issued: Jan 22nd, 2013 10:05AM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Timing of incoming weather is uncertain on Wednesday
Weather Forecast
Tuesday night and Wednesday: The frontal system is pushing its way into the interior and precipitation should start around Wednesday morning. 10 to 15 mm (possibly more in W and S of region) is expected to fall during the day with moderate to strong winds from the SW in the alpine. Freezing levels will lower to valley bottom and the inversion will disappear. Thursday: A break before the next system. Expecting some clearing, winds tapering off staying from the same direction, temperatures also staying cool and freezing level to valley bottom.Friday: Expecting light precipitation and moderate SW winds.
Avalanche Summary
Numerous moist loose avalanches up to size 1.5 and snowballing on S facing slopes was reported.
Snowpack Summary
Storm snow accompanied by strong SW-W winds will create loose snow concern in sheltered areas and new wind slabs in the alpine and at treeline on lee slopes. These new layers will most likely be touchy for a certain time and could also put on the needed load to awake the deeper instabilities that have been unreactive to skier traffic lately. The new snow will be sitting on a variety of surfaces; sun crust on S facing slopes, surface hoar layer mostly found in shaded-sheltered areas below treeline, facets and old windslabs that were breaking down. The early January surface hoar layer found under the top 50-70 cm, which has been unreactive to skier traffic but still producing the odd sudden planar shears especially under the elevation of 1500 m. in sheltered areas, could become more reactive with this added load. Under these concerning layers, a strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.Â
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: Jan 23rd, 2013 2:00PM