The storm systems on Monday morning. (NASA/NOAA GOES Project)
A deadly tornado outbreak on Sunday and Monday tore through multiple states, killing more than 30 people and devastating communities from Oklahoma to Alabama.
This video animation from NASA demonstrates just how massive this weather system has been. It shows what a NASA satellite captured from Saturday night through Monday morning, letting you see the line of storms develop and move east:
For more on the impact of these storms, head to Capital Weather Gang.
Mark Berman is a reporter on the National staff. He runs Post Nation, a destination for breaking news and developing stories from around the country.