More than 30 million people across the Midwest and Northeast are under winter weather alerts as a powerful storm system disrupts holiday travel.

Blizzard conditions with strong winds and whiteout visibility have affected parts of the Midwest, causing road closures, power outages, and significant flight delays and cancellations nationwide.

Severe thunderstorms and possible tornadoes have also damaged communities in Illinois as a sharp cold front sweeps across the central U.S.

Temperatures are dropping rapidly behind the front, shifting from above-average warmth to well below normal in many regions, CNN has reported.

With over 100 million people expected to travel by car for year-end trips, authorities are urging the public to avoid unnecessary travel due to dangerous conditions.