Central Sierra Nevada

Wet surface snow on sunny slopes may allow for some small and isolated surface instabilities as daytime warming progresses. Encountering an isolated unstable slab of wind drifted snow is unlikely but not impossible. Watch out for isolated areas where 6+ inches of wind drifted snow sits on top of softer, weaker, sugary snow.

Normal caution

Wet Loose avalanche problem: Warming air temperatures today and decreasing winds will allow for surface wet snow formation on sun exposed slopes. The recent storm snow is either close to or has become fully assimilated with the older melt-freeze layer across most E-SE-S-SW-W aspects. Small and isolated surface wet snow sluffs are possible today but larger problematic avalanches remain unlikely. If you are triggering roller balls and pinwheels, move to lower angle terrain.

Wind Slab avalanche problem: The recent new snow followed by strong to gale force NE winds created areas of blowing and drifting snow on Tuesday and Wednesday. Most observations have indicated that the wind slabs formed where this blowing and drifting snow deposited are now stable. The exception is in very isolated locations where a wind slab 6+ inches thick was able to deposit on top of old weak faceted snow from the Jan/Feb dry spell. This setup has been seen in isolated distribution on shaded NW aspect near treeline to below treeline terrain where a wind slab was able to cross load on top of the sugary faceted snow. If you get into a shaded area where surface penetration into cold snow is getting deeper, take a few seconds to check if you have a slab of newer snow on top of sugary snow. If so move cautiously around this area.

While the vast majority of backcountry travelers will not encounter unstable snow today. Minimize the consequences of an unlikely and unexpected encounter with a wet loose or wind slab avalanche by sticking to well disciplined, best practice techniques for travel in or below avalanche terrain. If needed, read up on the definition of "normal caution".

Recent Observations:

• Snowmelt has sped up over the last two weeks exposing more obstacles (rocks, bushes, etc) and areas of bare ground on SE-S-SW aspects.
• The recent light snowfall has helped to smooth the previously rough snow surfaces in some areas. Variable snow surface conditions ranging from firm ice to soft snow remain widespread.
• A well-bonded and consolidated snowpack exists across nearly all aspects and elevations. Gradual near-surface faceting has created weak snow in the top portion of the snowpack on many wind-protected and semi-wind protected NW-N-NE aspects. For the most part, more new snow is needed on top of this weak layer before slab avalanche problems occur. Note the isolated exception outlined above.