Texas flash flood ‘exceeded flow over Niagara Falls’

By the Climate Centre
Phone-camera videos taken by Texas residents have graphically illustrated the terrifying speed and ferocity of the flash flooding on the River Guadelupe that has claimed scores of lives, many of them children at a summer camp, and left others still missing Monday.
The US National Oceanic and Atmospheric Administration released an animation showing how quickly the rainfall across central Texas built up from the remains of Tropical Storm Barry, with an estimated three months’ worth of rain falling in a few hours.
NOAA data indicates this amount of rain could be expected once every 500 years with an atmosphere not warmed by climate change.
The disaster was caused by thunderstorms fuelled by what was left of Barry, which hit Mexico earlier last week in the week after sucking up saturated air from the warm waters of the Gulf of Mexico.
“In just few hours, one-hundred-billion gallons of water fell [in an area roughly centred on Camp Mystic] – that is more than the amount of water that falls over Niagara Falls daily,” Texas KSAT weather radio reported.
The Texas Hill Country is part of what is known as Flash Flood Alley for a variety of geographical reasons and “because of the area’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,” according to Texas Public Radio.
“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 Guadalupe River flooded in most decades of the 20th century.
‘Our hearts are with their families’
The American Red Cross is working side-by-side with partners to support emergency shelters, providing food, relief supplies, and financial and family travel assistance.
Several emergency shelters are open for those seeking refuge or a place to charge their phone and connect with the National Society’s mental health volunteers, and there are two reunification centres open to help families reconnect.
“Our hearts are heavy as we witness the devastating impact of the recent floods in Texas,” the American Red Cross said. “The loss of life and destruction are truly heart-breaking.”
IFRC Secretary General Jagan Chapagain, referring to those lost and still missing, said on X/Twitter: “Our hearts are with their families.”
Climate Centre science lead Liz Stephens said today: “Obviously, the quality and timeliness of the warnings issued ahead of this disaster will now come under scrutiny.
“The role of climate change will also be the subject of debate. We know that a warmer atmosphere holds more moisture; so when these weather systems form, climate change may be making them more intense and more deadly, but we don’t know with the same certainty how climate change is influencing local weather patterns.
“Again and again globally, with climate change fuelling more intense rainfall, we have seen how our early warning systems – even good ones – are just not designed for what’s possible even now, let alone what’s coming in the future. And it’s the most vulnerable – children, the elderly, those with limited mobility – who are most at risk.”
US-based Climate Centre hydrometeorologist Andrew Kruczkiewicz adds: “Living with flood-risk is part of the way of life in Flash Flood Alley – particularly at this time of year.
“But in the future, ensuring that warnings are not only available and accessible but likely to lead to action – including in the middle of the night when people are asleep – is key, as weather become more intense, more complex and more sudden.
“We may find ourselves pairing new with familiar, trusted technology, like old-fashioned radios that sound an alarm loud enough to wake people up, or a network of sirens.”
Texas National Guard personnel search the river banks in the immediate aftermath of the flash floods in the state’s Hill Country over the weekend. (Photo: @TXMilitary via X)