Central Sierra Nevada

Challenging travel conditions including icy crusts and wet heavy snow represent today's main concern in the backcountry. Triggering an avalanche remains unlikely on a regional scale. Stay alert since some unstable snow may still exist on isolated terrain features especially where the snowpack remains shallow and weak. LOW avalanche danger exists for all elevations. Travel using normal caution and being willing to step back into safer terrain if warranted.

Normal caution

Despite unseasonably warm temperatures overnight, the snow surface should have radiated enough heat out into the clear night skies for some places to refreeze. The weak refreeze won't last long on sunny slopes. Expect wet snow on these aspects when the surface crusts melt. Some rollerballs, pinwheels, and other small loose wet instabilities may also form on the most sun-exposed slopes. These should remain small since the January sun is weak and low in the sky and the days are short.  On northerly aspects, expect to find a mix of firm icy surfaces and breakable crusts. These snow conditions could present a challenge to backcountry travelers.

Avalanche activity remains unlikely even though the weak layers buried in the snowpack still exist. No avalanches have been reported on the persistent weak layer in the last 2 weeks. Most data and observations indicate that the weak layer has become dormant. However, snowpit tests in a few places - specifically in the Carson and Ebbetts Pass areas - continue to yield unstable results on the Dec 11 facets.

Create travel plans focusing on terrain and snow conditions that match your group's skill level. Monitor the snowpack and conditions while traveling and be willing to step back into safer terrain when conditions warrant. Even though the avalanche danger is LOW, don't ignore signs of instability (including unstable snowpit test results, whumpfing, or cracking).

Recent Observations:

*  The majority of recent observations show improving stability associated with Dec 11 persistent weak layer. In the northern 2/3rds of the forecast area, snowpit tests point to the layer going dormant. Some unstable test results have continued to occur in the southern 1/3rd of the forecast area, especially in the Carson Pass and Ebbetts Pass areas where the snowpack remains shallower and weaker overall.

* Unstable snowpack test results were reported on the Dec 11 persistent weak layer from the Blue Lakes area yesterday (Carson Pass area).

* Observers reported firm rain crusts on northerly aspects up to at least 9700 ft on Melissa Corey Peak (Carson Pass area) and on Relay Peak (Mt Rose backcountry). This crust likely extended up to at least 10,000 ft.

* Observations from Relay Peak targeting the buried Dec 11 facets did not show signs of instability.

* Small rollerballs and pinwheels occurred on sunny E aspects on Relay Peak in response to ski cuts. Where there was snow on south-facing slopes, more supportable melt-freeze conditions existed but snow coverage is minimal on these slopes.