Avalanche Forecast
Issued: Mar 1st, 2018 4:44PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
TONIGHT: Snow. Accumulation 10-15 cm. Ridge wind moderate, east. Temperature near -8. Freezing level lowering to valley bottom.FRIDAY: Snow. Accumulation 10-20 cm. Ridge wind light, northeast. Temperature near -3. Freezing level 800 m.SATURDAY: Mainly cloudy, light flurries. Accumulation 2-5 cm. Ridge wind light, east. Temperature near -4. Freezing level 600 m.SUNDAY: Mix of sun and cloud. Ridge wind light, east. Temperature near -6. Freezing level 500 m.
Avalanche Summary
Storm snow has grown touchy cornices and formed widespread soft storm slabs near ridge tops and open areas at treeline and below. On Wednesday there were reports of several natural and skier triggered size 1 loose, dry storm snow releases on all aspects above 1700 m, as well as a few size 2-2.5 natural storm slab releases on northeast aspects that where possibly cornice triggered.Tuesday a size 2.5 natural storm slab release that was likely triggered by a cornice collapse, was reported on a northerly aspect in the alpine. Cornice collapses up to size 1.5 were also reported but did not produce slab releases on the slopes below.Numerous wind slabs up to size 2 and loose dry avalanches up to size 1.5 were reported from the Lizard Range on Monday running either naturally or triggered by skiers testing small slopes. Explosives triggered widespread storm slabs up to size 1.5 and size 2 results on northerly aspects. Crown depths typically ranged from 40-80 cm.
Snowpack Summary
Approximately 40-70 cm of light dry snow has fallen in during the past week. This storm snow overlies various old surfaces including old hard wind slabs, crusts, facets and spotty surface hoar. Also in the upper to mid snowpack, a surface hoar layer buried mid-February is now 80 to 100 cm below the surface on sheltered northerly aspects.Deeper in the snowpack, the widespread mid-December weak layer sits about 200 cm deep. This consists of a crust, facets or surface hoar.Near the base of the snowpack, a crust/facet layer could be awoken from a thin-spot trigger point, or with a very large load like a cornice fall.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 2nd, 2018 2:00PM