Sign up for TPR Today, Texas Public Radio's newsletter that brings our top stories to your inbox each morning.
Flash flooding is a common occurrence in the Hill Country, but even longtime residents were stunned when the Guadalupe River rose like it did early Friday morning. Ten to 12 inches of rain dumped on Kerr County in a matter of hours, producing more water than the daily flow over Niagara Falls, KSAT in San Antonio reported.
What is flash flood alley?
It's what meteorologists and locals alike call the Texas Hill Country because it's one of the most dangerous regions in the country for flash flooding.
As any Texan knows, the weather here is unpredictable. That's because of the state's unique position between cold, dry air from the north and moist, warm air from the Gulf of Mexico. Central Texas in particular is prone to intense rainstorms. Water fills the Colorado and Guadalupe rivers and their tributaries, making the area a popular destination for boaters and swimmers.
But when certain weather patterns collide like they did on Friday, the area is inundated with water that rushes through the hills and canyons. The abundant limestone keeps the water from soaking into the ground, so it rushes into the valleys, Sarah Spivey, a meteorologist with KSAT, told NPR.
Friday's rain was particularly intense because of a lingering tropical storm that hit Mexico and migrated to Texas.
"Normally weather systems and the remnants of tropical systems will get picked up by the jet stream" – air that moves weather patterns – "and that's just not over Texas currently," Shel Winkley, a meteorologist with Climate Central, a nonprofit that studies climate change, told The Associated Press.
Put another way, "we're essentially looking at a rain bomb directly overhead," Spivey said.
How are residents warned of flooding?
Central Texas residents are fairly accustomed to flash flood alerts from the National Weather Service (NWS) pinging their phones.
The NWS issues different kinds of watches and warnings depending on the weather and severity of conditions, with the most extreme advising residents in flood-prone areas to immediately flee to higher ground.
Flooding history
The Guadalupe River flooded in nearly every decade of the 20th century. Ten people – teens attending a summer camp in Comfort – died in 1987 during a flash flood when their school bus drove into water. A flood in 1998 was the deadliest in the area up until that point, killing 12 people.
Friday's flood has so far claimed 59 lives, including 38 adults and 21 children.
The Guadalupe-Blanco River Authority and Federal Emergency Management Agency, or FEMA, released a report following the 1998 flood that advised residents on how to stay safe.
"The lesson to be learned," it read, "is that given the right circumstances, a rare combination of weather events can shatter previous limits – including man's best efforts to determine the magnitude of floods."
Copyright 2025 Texas Public Radio