About 70 million people are expected to be affected by the storm over the next few days, with 30 million expected to see hail. Temperatures from the Rocky Mountains to the northern Great Plains will range from minus 34 degrees Celsius to minus 48 degrees Celsius on January 20. Western New York is facing the risk of heavy snowfall, with some areas expected to receive up to 60 to 90 centimeters (24 to 36 inches).

Meanwhile, California continues to face a high risk of wildfires amid strong, dry winds. The NWS has warned of "extremely dangerous conditions" for parts of Los Angeles and Ventura counties from noon on January 20 to the morning of January 21 (local time), with Santa Ana winds reaching a maximum speed of 113 km/h along the coast and 160 km/h in mountainous terrain. Firefighters continue to battle two major fires, the Palisades and Eaton fires in Los Angeles, which began on January 7 and are only partially contained so far, according to AFP.