Here’s what to know about how scientists determine how extreme a flood is and how common these extreme events are becoming.

These terms might sound like ... do—occur far more frequently than their names imply, due in part to climate change altering weather patterns worldwide. The terms "100-year flood" or "500 ...

For example, a meteorologist can look ... like rolling a pair of dice and getting double sixes twice in a row. It’s rare, but statistically possible. Another term people hear during an impending ...