In the wake of Hurricane Helene, the Southeast United States has been hit with an unprecedented deluge of water—more than 40 trillion gallons of rain—leaving behind devastation that meteorologists are calling “apocalyptic.”
This massive volume of rain is enough to fill Lake Tahoe once, or the Dallas Cowboys stadium a staggering 51,000 times. It’s the kind of record-breaking weather event that has stunned experts and left communities grappling with the aftermath of one of the largest storms in decades.
“This is an astronomical amount of precipitation,” said Ed Clark, the head of NOAA’s National Water Center, emphasizing the sheer scope and intensity of the rainfall. He noted that, in his 25 years of experience, he had never witnessed anything so geographically extensive or so powerful.
Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the rain totals using satellite and ground data and confirmed that the eastern U.S. was drenched by 40 trillion gallons of water through Sunday alone, with 20 trillion gallons specifically hammering Georgia, Tennessee, the Carolinas, and Florida—courtesy of Hurricane Helene.
While the catastrophic rain damage is centered in these states, the storm’s impact was amplified by several factors, including geography. As Clark and other experts pointed out, much of this rainfall poured down on mountainous regions, where the terrain intensified runoff and made flooding even more severe.
High-elevation areas like North Carolina’s Mount Mitchell saw more than two feet of rainfall, while the town of Busick recorded a staggering 31.33 inches. When you drop trillions of gallons of rain on the Appalachian Mountains, it all flows downhill, compounding the destruction in low-lying areas.
But this wasn’t just a one-off event—Hurricane Helene was part of a dangerous weather cocktail. A slow-moving low-pressure system had already parked itself over the Southeast, bringing days of heavy rain, and an unnamed coastal storm added even more precipitation before Helene arrived.
Together, these systems funneled warm moisture from the Gulf of Mexico, setting the stage for what meteorologist Ryan Maue called a “perfect storm” of conditions. The fast-moving Helene, one of the largest storms in recent history, hit the already saturated region hard, dumping more rain and overwhelming local water systems.
And the damage is nothing short of catastrophic. More than 100 lives have been lost, and entire communities are underwater, with the storm leaving a trail of destruction across several states. The floodwaters are receding slowly, but the process of recovery will take much longer.
Experts are increasingly attributing the intensity of these storms to climate change. As the world warms—over 2 degrees Fahrenheit since pre-industrial times—the atmosphere can hold more moisture, leading to heavier rainfall. This basic law of physics means that storms like Helene are becoming wetter and more dangerous. Kathie Dello, North Carolina’s state climatologist, noted that while the region is no stranger to tropical storm impacts, “these storms are wetter and warmer,” causing more widespread destruction than in the past.
Scientists at the Lawrence Berkeley National Lab backed this up with a quick analysis, estimating that climate change contributed 50% more rainfall during Helene in parts of Georgia and the Carolinas. While the debate about how much of the storm’s intensity is directly linked to climate change continues, for many meteorologists, the “fingerprints of climate change” on Helene are unmistakable.
