What are the major weather threats and impacts as the severe winter storm system moves across the United States?

The severe winter storm system is creating multiple dangerous weather threats as it moves eastward across the United States. The storm has already generated reported tornadoes in Mississippi and Alabama, while depositing more than a foot of snow in parts of Virginia, demonstrating its widespread impact and intensity. The storm's path extends from the Great Lakes region to the Northeast, bringing a dangerous combination of rain, snow, and ice conditions. This creates significant public safety concerns, including treacherous driving conditions and extensive vehicle pileups that have already resulted in multiple injuries. In western states like Oregon and California, the situation is particularly critical due to mudslide risks following recent wildfires. The combination of heavy precipitation on fire-damaged terrain has prompted evacuation warnings, as communities face the dual threat of immediate weather hazards and longer-term geological instability from compromised hillsides.