An avalanche warning for areas above 5,500 feet, issued by the Forest Service’s Mount Shasta Avalanche Center, is in effect until noon on Thursday, Jan. 21.
The mountains surrounding the city of Mount Shasta had received three to four feet of new snow since Sunday as of Tuesday morning, and since then, and additional 10 to 20 inches has likely fallen based on water amount recorded in  Mount Shasta City.
An additional 20 to 40 inches of snow is expected through midday Thursday.
This very heavy snowfall in combination with strong winds above tree line are adding to the avalanche danger by further loading slopes, the Avalanche Center said in a press release.
Weak layers exist in the snowpack. This, combined with heavy snowfall and wind loading, has caused the avalanche danger to increase.
Natural and human triggered avalanches will be likely today through midday Thursday in the backcountry above 5,500. While the avalanche danger will likely slowly diminish with precipitation rates and diminishing winds, the snowpack will remain sensitive and extreme caution is advised.
Stay off of and out from underneath slopes steeper than 30 degrees. People without extensive backcountry avalanche skills are advised to stay out of the backcountry.
This statement does not include ski areas and highways where avalanche mitigation is normally done, the release states.
For more information, visit www.shastaavalance.org