Severe winter weather out West prompted avalanche warnings in four states on Thursday.
The National Weather Service and the U.S. Forest Service issued an avalanche warning for Colorado, California, Idaho and Montana following heavy snowfall in parts of each state.
In Colorado, extremely dangerous avalanche conditions are expected to form early on Friday and throughout Saturday, the NWS said.
According to the NWS, both natural and human-trigger avalanches are likely to happen.
Many people are expected to go skiing this weekend, as several ski resorts in the Rocky Mountains have just opened, officials said.
The U.S. Forest Service Sierra Avalanche Center issued an avalanche warning from Thursday morning to Friday morning in the Central Sierra Nevada Mountains, which is in California.
According to the Avalanche Center, additional snow and strong winds will place an extra burden on an already weak snowpack.
"Avalanche activity could be widespread and some avalanches could be large and destructive," the Avalanche Center said.
According to the UC Berkeley Central Sierra Snow Lab, a research field station focusing on snow, the area received 5.7 inches of snow overnight and is expecting another 20 to 30 inches of snow on Thursday.
A major storm, bringing heavy snow, coastal rain and high winds, is impacting 16 states as it moves across the West.