Wettest storms in U.S. history. Hurricane Harvey is at the top, with 49.32 inches of rain, as of 29 August 2017. Graphic: Capital Weather Gang / The Washington Post

By Jason Samenow
29 August 2017
(The Washington Post) – The rain from Harvey is in a class of its own. The storm has unloaded over 50 inches of rain east of Houston, the greatest amount ever recorded in the Lower 48 states from a single storm. […]John Nielsen-Gammon, Texas state climatologist, said a rain gauge near Mont Belvieu at Cedar Bayou, about 40 miles east of Houston, had registered 51.9 inches of rain through late Tuesday afternoon. This total exceeds the previous record of 48 inches set during tropical cyclone Amelia in Medina, Texas in 1978.All rainfalls totals from this storm are still preliminary and require review. But, if verified, this amount breaks not only the Texas state rainfall record but also the record for the remaining Lower 48 states.Hawaii has logged isolated reports of greater amounts at high elevations from tropical systems, but the footprint from Harvey in Southeast Texas is much larger. It has produced at least three feet of rain over most of the Houston region, affecting more than 5 million people.“The 3-to-4 day rainfall totals of greater than 40 inches (possible 50 inches in locations surrounding Santa Fe and Dickinson) are simply mind-blowing that has lead to the largest flood in Houston-Galveston history,” the National Weather Service office serving Houston wrote.Nielsen-Gammon found Harvey’s total rainfall concentrated over a 20,000-square-mile area represents nearly 19 times the daily discharge of the Mississippi River, by far the most of any tropical system ever recorded. [more]

Harvey marks the most extreme rain event in U.S. history