Continuous winds and cold temperatures ushered in a weak disturbance on Monday. Snowfall totals ranged from 1-7” through the region, with the greatest amounts in the Mammoth and June areas. Steady moderate winds from the southwest had an easy time of redistributing cold and soft snow onto leeward slopes through Tuesday. Wind affected snow surfaces were widely observed. Mammoth Mountain Ski Patrol reported many small soft wind slabs releasing during control work on Monday, but fewer when they reached the upper mountain yesterday morning. Given a short amount of time to adjust, the snowpack seems to be adapting to the load and strengthening. But don’t rule isolated wind slabs out of your hazard and terrain evaluation just yet. Hollow sounding slabs on leeward slopes may still be triggered by a rider’s weight.
And finally, those cold winds have given way to one of the first extended high pressure systems of the season. While it’s far from the tropical vacation that East Side residents dreamed of during the endless stream of Atmospheric Rivers that swept over us earlier this month, temperatures will be above average and winds calm through Thursday. But don’t forget what intense warming will do to the top of the snowpack and the rock outcrops that surround your favorite backcountry chutes and bowls. When unconsolidated snow is newly warmed loose wet avalanches will become a problem. Fortunately the nights will be cold and help keep the melting in check, but as temperatures rise throughout the day be on the lookout. Western slopes will receive more radiation than they have so far this season, now that the sun is getting higher in the sky, and we may see some wet slides on those aspects for the first time. Enjoy the mid winter sun, but don’t ignore obvious signs of instability. Look for roller balls releasing from under cliff bands and on steep solar slopes. Even small point releases are good indicators that slopes are becoming unstable and that larger avalanches may be possible. These smaller slides can knock you off balance and can carry you into dangerous terrain if you aren’t careful.