Atmospheric river intensity scale (IMAGE) American Geophysical Union Caption The intensity of an atmospheric river depends on how long it lasts (typically 24 to 72 hours; horizontal axis) and how much moisture it moves over one meter each second (measured in kilograms per meter per second; vertical axis). While weaker atmospheric rivers can deliver much-needed rain, more intense storms are more damaging and dangerous than helpful. Credit AGU, after Ralph et al. 2019 (DOI: 10.1175/BAMS-D-18-0023.1) Usage Restrictions Reproducible with credit, may not be altered. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.