Epic deluge in Hawaii may have broken all-time U.S. rainfall record, with 4 feet in 24 hours
A devastating flash flood event in mid-April caused widespread damage on the lush Hawaiian island of Kauai. Now comes word that during the 24-hour period between April 14 and 15, a staggering 49.69 inches of rain fell at a rain gauge about 1 mile west of Hanalei.
If this amount is verified by the National Climatic Extremes Committee, which is part of the National Oceanic and Atmospheric Administration (NOAA) and serves as a sort of Guinness Book of World Records for weather and climate, it would be the heaviest 24-hour rainfall total ever recorded in the U.S.
The current record is 43 inches, set on July 25-26, 1979, in Alvin, Texas. It would also crush the state record of 38 inches, which was also set in Kauai, back in 1956.
The committee members will review the rain gage to determine if it was functioning properly at the time of the rainstorm. This particular gage is operated by a nonprofit organization called the WAIPA Foundation. It's possible that the committee will conclude that the amount of rain was actually less than recorded, or conversely, that it underestimated the rainfall total.
It's not surprising that a national rainfall record would come from Kauai, since it's rugged terrain contains some of the wettest landscapes on Earth. Mt. Waialeale, for example, receives about 460 inches of rain per year, and is the wettest place in the country.
The April rains, though, were unusually intense and widespread, causing flash flooding throughout the island and forcing thousands to evacuate. Homes, businesses, and infrastructure was damaged or destroyed in a disaster that few in the continental U.S. heard of.
This rainstorm is in keeping with climate change trends, as global warming is already making extreme precipitation events both more frequent and intense.
No studies have yet been done on this particular event to see how climate change affected it, but other research has shown that global warming has made heavy rainfall events, including Hurricane Harvey, which was the most extreme rainstorm on record in the U.S., much more likely.
Andrew Freedman is Mashable's Senior Editor for Science and Special Projects. Prior to working at Mashable, Freedman was a Senior Science writer for Climate Central. He has also worked as a reporter for Congressional Quarterly and Greenwire/E&E Daily. His writing has also appeared in the Washington Post, online at The Weather Channel, and washingtonpost.com, where he wrote a weekly climate science column for the "Capital Weather Gang" blog. He has provided commentary on climate science and policy for Sky News, CBC Radio, NPR, Al Jazeera, Sirius XM Radio, PBS NewsHour, and other national and international outlets. He holds a Masters in Climate and Society from Columbia University, and a Masters in Law and Diplomacy from The Fletcher School at Tufts University.
