Central Sierra Nevada

Avalanche problems

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  This morning's firm, frozen snow surfaces may melt away, exposing leftover wet, loose snow on sunny slopes as the day warms up. If the snow surface starts to feel wet, becomes unsupportable, or you see other indicators of wet surface snow, like roller balls or pinwheels, it's time to move off slopes steep enough for wet, loose snow to slide down. 

  Temperatures finally dropped below freezing in most places last night. These colder temperatures, combined with areas of clear skies, should have allowed a crust of firm refrozen snow to form on the surface in many areas. Wet snow will still exist below this crust. March sunshine and above-freezing air temperatures today will help melt last night's crust on sunny slopes, potentially exposing the wet snow lingering below the surface. Once this happens, avalanches of wet, loose snow will become possible on steep sunny slopes. These avalanches may start small, but as they move downhill they entrain more snow, so long, steep slopes can produce larger wet loose avalanches. This problem should be less prevalent on shady northerly aspects, but those slopes may remain firm and frozen for most of the day.