New scale will measure ‘atmospheric rivers’ on US West Coast
SAN DIEGO (AP) — Scientists in California are introducing a scale to measure “atmospheric rivers,” the weather phenomenon that can dump massive quantities of Pacific Ocean water on the U.S. West Coast, carrying it through the air from as far away as Hawaii.
The Scripps Institution of Oceanography at the University of California, San Diego announced Tuesday that the 1-through-5 scale will characterize the strength of atmospheric rivers from “weak” to “exceptional.”
Under the system, an atmospheric river in January 2017 would have been category 4 — or “extreme” — because it persisted for 36 hours and produced up to 14 inches of rain in the Sierra Nevada.
Scripps says it’s similar to scales that gauge hurricane, wind, or tornado intensity and could aid flood response and water management.