Central Sierra Nevada

Light rain and high elevation snow is expected for our forecast area today.  These weather conditions should have limited change on avalanche activity.  Avalanches are unlikely, normal caution is advised if traveling in the backcountry today.  

Limited snow is available for wind transport today due to rain crust on the snow surface up to 8300' and melt freeze crusts on windward aspects up to 9000-9500'.  Very little snow accumulated yesterday and today's snow levels are forecasted to rise up to around 9000', where up to 1 to 4 inches of snow is possible.  Some blowing snow could occur at these higher elevations with some small wind slab formation.  Additional rain is expected today, potentially up to 9000'.  This rain will be falling on a snowpack that has already been rained on, with rain crusts that exist up to around 8000 to 8500'.  Depending on where snow levels end up, some small wet loose instabilities could occur, most likely where this rain falls on colder higher elevation snow.  Both of these problems are expected to be limited today for backcountry users with the small amount of precipitation forecasted and our current snow surface conditions.

The Dec 12 persistent weak layer and basal facets continue to exist in the southern and eastern portions of the forecast region.  These areas are mostly above 8000-8500' and in locations with a shallower and weaker snowpack.  Both of these layers are unreactive from an avalanche perspective.  Some lingering signs of instabilities have continued in the form of unstable snowpack test results in isolated locations.  In many areas, these weak layers have gained strength as our snowpack becomes deeper and stronger.  These weak layers could reactivate in the future if a large storm loading event were to occur. 

Depending on where you travel today in the backcountry, variable snow surface conditions could be encountered.  Use normal caution if heading out today.  Make sure you have a plan ahead of time with your group and everyone is on board in the decision making process.