New snow and strong southwest winds are forming reactive slabs. Avoid freshly wind loaded terrain features. The buried crust offers a slick bed surface for avalanches.
New snow and strong southwest wind are forming fresh storm slabs. Watch for fat deposits in leeward terrain features such as ridge crests and roll-overs.
Storm slabs may be particularly reactive where they accumulate over a weak layer such as surface hoar or a crust now buried 20-50 cm deep. The crust offers a slick bed surface for avalanches.
Monday night: 5-10 cm new snow, wind increasing to strong southwest, freezing level 700 m.
Tuesday: 10-20 cm new snow, strong southwest ridgetop wind, alpine high -5 C, freezing level 1200 m.
Wednesday: 5-15 cm new snow, light to moderate southwest ridgetop wind, alpine high -4 C, freezing level 1200 m.
Thursday: 10-20 cm new snow overnight, wind easing to light northwest, alpine high -5 C, freezing level 1300 m.
On Sunday, small natural and skier controlled size 1 loose dry and wind slab avalanches were reported running on the crust.
Solar triggered loose snow avalanches size 1-2 were reported on steep solar aspects in the alpine on Saturday. A size 1.5 natural cornice fall was also reported in this MIN from the Garabaldi area.
Have you been out and about in the mountains? If so please submit your observations to the Mountain Information Network (MIN). It doesn't have to be technical - photos are especially helpful! Thank you so much for all the great MINs submitted so far!
15-25 cm of new snow is forecast to fall by the end of the day Tuesday. As it falls, the new snow iis being loaded into lee features in wind exposed areas by strong southwest wind.
In wind sheltered areas, the new snow may be falling on a layer of small surface hoar crystals. A second layer may also exist in close proximity below.
A crust is now buried by 20-50 cm of snow at elevations above 1000 m. Prior to the new snow, the crust was punchy below 2000 m with a moist snowpack below. The new snow will likely help with bridging, and improve travel conditions.
Snowpack depths change rapidly with elevation, with 0-50 cm below treeline to 170 cm in the alpine.
