A once-in-a-generation storm system is set to impact millions across the Midwest and South, bringing significant risks of tornadoes and catastrophic flooding. Forecasters have issued dire warnings, predicting historic rainfall amounts that could lead to life-threatening flood conditions and a potential tornado outbreak. Areas from Arkansas to Indiana are particularly vulnerable, with flash flood watches and tornado warnings already in effect. Weather alerts have been issued for severe storms throughout the week, including damaging winds, large hail, and prolonged heavy rainfall. Communities are preparing for an unprecedented weather event that may bring more than a foot of rain in some regions, with live updates tracking the severe storms as they move towards major urban areas like St. Louis and Cincinnati.