With the front of the incoming winter storm arriving today, dangerous avalanche conditions will exist. Human-triggered avalanches are likely and naturally occurring avalanches are possible. Gale-force winds and blowing snow will create challenging travel conditions, conservative decision-making and cautious route finding will be essential.
Rapid snowfall rates will create instabilities within the new snow. Rapid warming in the snowpack the past 2 days followed by freezing conditions produced a melt-freeze surface crust. This will be the bed surface theat the new snow could slide on.
Winds speed on the Sierra crest could exceed 100 mph today with the incoming storm. Up to a foot of snow is expected today creating the recipe for wind slab avalanches. Be aware of leeward slopes, cross-loaded slopes, and terrain features that amplify the effects of drifted snow.
A winter storm warning is in effect starting at 10 am this morning and continues throughout the weekend. 12-18 inches of new snow is expected today and tonight. Rapid snowfall rates and strong wind from the SW will create fresh wind slab and storm slab problems. March 2nd and 3rd brought out the sun after several days of blizzard-like conditions. The cold snow that fell during the blizzard experienced rapid warming by the strong solar radiation of the March sun. Temperatures rose into the 40s and a melt-freeze crust formed on solar aspects. Watch out for this crust as the new snow will fall on it, creating a sliding layer.
