WASHINGTON — Long before sunrise in Texas, a shallow spot of the Guadalupe River rose above the height of a two-story house in just five hours on Thursday, sending a rush of water through a region still weary from last summer’s fatal flash floods.
The dangerous flooding for a second consecutive year set off dozens of high-water rescues, washed out roads and killed at least one person, authorities said. Relentless downpours served as another frightening reminder of the flood-prone Texas Hill Country, following what experts say was fueled this time by the right mix of air and lots available moisture.
“Last year, it was one big wave that came through. And it wiped everything out, and then it receded, and then we could deal with the damage. This time, we’re on day three of heavy rain and everything keeps continuing to rise, and it’s expected to rain today and tonight,” said Suzanne Sutphin Gschwind of Kerrville, where some of the worst flooding took place.
Hot weather over the middle of the continental United States ensured storms that formed would move slowly, and rounds of rain over roughly the last three days at times reached several inches an hour. The flooding is “about as bad as it gets” – conditions that are typically rare, said Bob Oravec, a meteorologist with the National Weather Service.
“Obviously, something like this doesn’t occur every year, but it has occurred over two years in a row and it has occurred over a region that is prone to flash flooding by its topography,” Oravec said.
Nearly 1 trillion gallons of water fell on the three hardest-hit counties in Texas over three days – Uvalde County alone got more rain in that period than California has seen over the last month, according to Ryan Maue, former chief scientist at the National Oceanic and Atmospheric Association.
Flooding over the Fourth of July weekend last year killed more than 100 people, including roughly two dozen children and camp counselors at Camp Mystic, a now-shuttered Christian camp for girls. These storms dumped rain on a wider area, overlapping with some of the places where floodwaters overturned cars, ripped down trees and sent rescuers hustling to save lives last July.
A local official in Travis County, which includes Austin, said people were trapped on barn roofs and in trees. Texas Gov. Greg Abbott said drones and helicopters were airborne for rescues.
“We are looking at every square inch of the entire area for anybody who may be stranded anywhere. And there will be help coming very rapidly to whoever may be displaced, wherever they are,” Abbott said.
The flood in Texas Hill Country
The rain hit Texas Hill Country, a part of central and south Texas with steep terrain. Shallow soil covers limestone hills that have been soaked for days. Instead of the land absorbing the water, it shoots into rivers with steep banks.
That causes water to rise fast, a dangerous scenario that catches people by surprise.
When rivers rise so fast “it’s almost like a river tsunami,” said Tyler Roys, a senior meteorologist with the forecasting company AccuWeather. These conditions are so deadly because water is heavy and moves quickly. Just one cubic foot of water – imagine a box a bit larger than the size of a basketball – weighs about 62 pounds (28 kilograms).
Compared to last year’s flood, the rain fell hard, but in some places it wasn’t quite as intense and rivers in many places didn’t rise quite as quickly, Texas State Climatologist John Nielsen-Gammon said. Plus, the previous days of rain previewed the flood threat.
“This one is producing greater overall precipitation totals, but it is mostly doing it with lower rain rates. They are still fairly high, but they aren’t as high as they were last year,” he said.
While swollen from rainfall, so far Guadalupe River levels have largely remained below record levels, some of which were reached during last year’s deadly floods. The river did surpass last year’s mark at the small community of Comfort, rising to 37 feet (11.3 meters) early Thursday, a mark 1.5 feet (0.5 meters) higher than it reached last year. At its height then, water weighing as much as the Empire State Building flowed downstream roughly every minute.
The river’s record at this spot is 42.3 feet (12.9 meters) set in 1869.
Climate change and forecasting
It is difficult, especially as storms are happening, to know whether climate change has made the event more likely or worse.
Oravec said that the conditions that created this storm – hot air that steers and slows storms – have long occurred, but that climate change could make these conditions more common. A warmer atmosphere also has the potential to hold more moisture and heavier rains.
Last year’s flooding did raise awareness of the dangers floods create, especially when they occur at night, Oravec said.
“I think overall it has been a good forecast. The effects are catastrophic, but the signal was there for potential heavy rainfall,” he said.
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Associated Press writers Christopher L. Keller in Albuquerque, New Mexico, Claudia Lauer in Philadelphia and Kathy McCormack in Concord, New Hampshire, contributed.
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