New snow amounts from the first half of this week range from 1.5 to 3 feet across the forecast area. The areas of greatest snowfall have occurred along the Sierra Crest in the northern half of the forecast area. The lower and middle end of snowfall amounts have occurred along the Sierra Crest in the southern half of the forecast area and along the Carson Range.

New snow this week was deposited onto bare ground, making the full height of the snowpack recent storm snow. Observed avalanche activity and evidence of snowpack instability have been focused on wind slabs that have formed on wind loaded slopes both near treeline and above treeline. Wednesday on Castle Peak (Donner Summit area), intentional skier triggered avalanches were observed on wind loaded test slopes in near treeline terrain on a NW aspect at 8,540'. These small wind slab avalanches occurred up to 1 foot deep in the snowpack. Click here for photos, snowpit profile, and more info. Larger slopes with larger and deeper slabs were observed in the area, but were not tested with a human trigger.

Looking forward for the next few days, lingering wind slabs are the ongoing avalanche concern. Human triggered avalanches will remain possible in recently wind loaded areas. Most of these locations will exist near treeline and above treeline. Ridgetop winds are forecast to shift to the NE late Thursday and become strong enough to create another round of wind loading and redistribution of snow on the ground, especially above treeline. Some warming is expected to occur through this weekend, but wet snow instability is not expected.

As you travel, make constant observations looking for indications of current or recent snowpack instability. The best indicator is recent avalanche activity. Other signs of snowpack instability including wind loading, collapse, audible whumpfing sounds, shooting cracks, and/or test slope failure are excellent indications that the snowpack in the immediate area is unstable. All that is needed is a slope steeper than 30 degrees and a trigger.

If headed out to travel on or near avalanche terrain, each person should travel with avalanche rescue equipment including a transceiver, probe, and shovel with which they are well practiced. Allow only one person at a time to travel on slopes that are steeper than 30 degrees. Many hazards such as rocks, down trees, and stumps are often hidden just beneath the snow surface. Travel cautiously and slowly as it is a very long winter after getting hurt this time of year. Often the best way to satiate early season excitement is to put fresh batteries in avalanche transceivers and practice rescue skills while out touring on snow covered forest roads.

Check out the avalanche tutorials specifically designed for skiers and snowmobilers at the Forest Service National Avalanche Center web site.

Current remote weather station data from the NWS can be found by clicking here. A general weather forecast for the area can be found by clicking here.

Please note: If you are intending to travel within the boundaries of a ski area that is not yet open for the season, no avalanche mitigation measures exist at this time. Please treat any closed ski area as the backcountry terrain and snowpack that it currently is. Respect any closure signs that may be in place at the parking lot or base area. Carry proper backcountry equipment and avalanche rescue equipment. Expose only one person at a time to avalanche terrain (which is often widespread and complex within a ski area). Do not traverse above others. Things may look the same and seem very familiar to an operating ski area, but from a safety standpoint, right now the avalanche risk is significantly higher.