Hurricane Helene’s death toll has surpassed 150 as searchers use helicopters to get past washed-out bridges and hike through wilderness to reach isolated homes.
Crews were still trudging through knee-deep muck and debris in the wake of the deadly category 4 storm that dumped more than 40tn gallons of rain on the southern US after it crashed ashore in Florida on Thursday.
The 40tn gallon calculation was made by meteorologist Ryan Maue, a former Noaa chief scientist, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations.
The amount of rainfall is enough to fill Lake Tahoe – with its depth of 1,645ft and surface area of 191 sq miles – or 60 million Olympic-sized swimming pools. It could also fill the Dallas Cowboys’ 80,000-seat stadium 51,000 times over.
“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration (Noaa)’s water center in Tuscaloosa, Alabama, according to the Associated Press.
Clark said the estimate of 40tn gallons was, if anything, conservative. Also, if that amount of water had fallen in the parched western states, it would have been enough to fill Lake Powell and Lake Mead twice over, he said.
“These storms are wetter and these storms are warmer,” North Carolina state climatologist Kathie Dello said. “There would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction.”
The area in North Carolina around Asheville, where the French Broad River and Swannanoa River meet, received more than 20in (51cm) over three days. For context, 8.4in over that time span would have been considered a once-in-1,000-year event by a metric created prior to climate change.
More than 1.7 million homes and businesses in six states from Florida to West Virginia remained without power Tuesday.