How weather conditions set the stage for deadly Texas flash floods
More than 12 inches (30 centimeters) of rain fell in the
Texas Hill Country
over a span of several hours early Friday, causing water levels to quickly rise, according to the weather forecasting company AccuWeather. The area is naturally prone to flash flooding, but this was an especially bad storm that hit during the vulnerable overnight hours, experts said. More than two-dozen deaths have been reported along with numerous rescues.
Meteorologists said that an atmosphere warmed by human-caused
climate change
can hold more moisture and allow bad storms to dump more rain, though it's hard to connect specific storms to a warming planet so soon after they occur.
'In a warming climate we know that the atmosphere has more moisture to give, to hold on to and then to release. But also the thing that we know about climate change is that our rain events are not as uniform as what they used to be,' said Shel Winkley, a meteorologist with Climate Central. 'So, you'll get these big rain events happening in localized areas, tapping into the historic level of moisture in the atmosphere.'
In recent weeks, flash flooding driven by bursts of heavy rain turned deadly elsewhere in Texas and in West Virginia. In
San Antonio
in June, more than 7 inches (18 centimeters) of rain fell over a span of hours, prompting dozens of rescues from the fast-rising floodwaters and killing at least 13. And in West Virginia that month, at least
nine people died
when as much as 4 inches (10 centimeters) of rain fell within 40 minutes and caused flash flooding in the Wheeling area.
Staggering rain runs off hard ground
Robert Henson, a meteorologist and writer with Yale Climate Connections, said this latest Texas rain storm was roughly a once-in-a-generation event. It fell in the Texas Hill Country where water quickly shoots down rugged hills into narrow river basins that swell quickly.
'As is often the case with the worst disasters, many things came together in a terrible way.' Henson said.
Plus, the area had been in a drought, so the water ran down the dry, hard land fast. That made it more dangerous for
children attending camp.
'A sudden surge of rain like that is going to have a harder time getting absorbed,' said Brett Anderson, a senior meteorologist at AccuWeather. 'It just runs right off of it. It's like concrete.'
The sheer amount of rain was overwhelming. Former NOAA chief scientist Ryan Maue, a private meteorologist, calculated Saturday morning that the storm had dropped 120 billion gallons of water on Kerr County, which received the brunt of the storm.
A storm with plenty of fuel
Moisture fueled the storm from many directions. Tropical Storm Barry formed briefly last weekend, moving over Mexico and then its remnants continued up into Texas. But the jet stream, a current of air that moves weather patterns, wasn't there to push that moisture away.
'Normally weather systems and the remnants of tropical systems will get picked up by the jet stream, and that's just not over Texas currently,' said Winkley, the Climate Central meteorologist. 'It's essentially a weather system without a road to get away from the Lone Star State.'
The warm water of the Gulf fueled the moist atmosphere. Even more moisture came from areas over the Pacific Ocean to the west. The combination gave the storm plenty of fuel once it got started.
Winkley said in the area that flooded, climate change might mean that rain storms are less common, but when they do occur they can be more severe.
Generally a warmer atmosphere can hold more moisture, creating conditions for storms to drop more rain.
'With climate change we have a warming atmosphere. A warmer atmosphere holds a lot more moisture, and we are seeing obviously much more total atmospheric moisture across the globe in recent years than we normally have,' said Anderson, the AccuWeather meteorologist.
___
The Associated Press receives support from the Walton Family Foundation for coverage of water and environmental policy. The AP is solely responsible for all content. For all of AP's environmental coverage, visit
https://apnews.com/hub/climate-and-environment
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Hill
3 hours ago
- The Hill
Turkey faces a ‘very risky week' for wildfires as flames also scorch parts of southeast Europe
ISTANBUL (AP) — Turkey faced a 'very risky week' for wildfires, an official said Monday, as blazes across parts of southeast Europe and the Balkans damaged homes and led to a huge firefighting operation that included evacuations. Nearly 100 people face prosecution over the fires in Turkey. Blazes erupted near Bursa, Turkey's fourth-largest city, over the weekend. A wildfire to the northeast of Bursa had been largely extinguished, but one to the south of the city continued, although its intensity had been 'significantly reduced,' Forestry Minister Ibrahim Yumakli told reporters in Ankara. He also said that a fire that has been burning for six days in Karabuk, in northwest Turkey, had also 'been reduced in intensity,' and a blaze in Karamanmaras in the south had largely been brought under control. A wildfire also erupted Monday in forests outside the western port city of Izmir, where 11 aircraft were helping ground-based fire units and residents battle the blaze. 'We are in a very risky week,' Yumakli said of the wildfires. Blaze in Greece In Greece, firefighters raced to tackle a wildfire that broke out Monday near a university campus close to the center of Athens. Water-dropping planes and helicopters buzzed over the city center as they headed to the wildfire near the National Technical University of Athens, located in foothills ringing the Greek capital. In all, 11 planes and eight helicopters were reinforcing 110 firefighters on the ground, the fire department said. Police announced road closures in the area, including to the only highway that circles the city. A waning fire on the island of Kythera, which lies south of the Peloponnese, was reinvigorated by strong winds. Over the weekend, the blaze burned through around 10% of the small island's land mass, triggering the evacuation of several villages. Bulgaria assisted by Turkish firefighters A Turkish firefighting team of 22 personnel and five vehicles crossed the northern border Monday to assist Bulgarian crews fight a large fire near the village of Lesovo, which was evacuated. The blaze was one of hundreds across Bulgaria, the most severe of which was near the southwestern village of Strumyani. The Interior Ministry described the fire as 'extremely large' and 'widespread,' leading to 200 firefighters being withdrawn because of the effects of high winds on the fire. Several villages have been extensively damaged, with dozens of homes burned to the ground. By Monday, 269 fires had been extinguished in the previous 24 hours, the government said. Other European Union countries have responded to Bulgaria's requests for help, sending firefighting helicopters and planes. In several instances, the cause of fires have been determined to be carelessness by people, such as open fires and discarded cigarettes. Senior Interior Ministry official Miroslav Rashkov said that two people had been arrested for deliberately starting fires and would be prosecuted. Volunteer firefighters killed Turkey has been fighting severe wildfires since late June. In Bursa, three volunteer firefighters were killed after their water tanker overturned, local news agency IHA reported. One died at the scene and the two others were pulled from the tanker and hospitalized but died late Sunday. The volunteer crew from the province of Bolu was on its way to the village of Aglasan, northeast of Bursa, to combat a blaze when the vehicle fell into a ditch beside a rough forest track, the agency reported. Separately, officials said earlier Sunday a firefighter died of a heart attack while battling a blaze. The fatalities brought the total deaths over the past month to 17, including 10 rescue volunteers and forestry workers killed Wednesday in a fire in the western city of Eskisehir. The huge blazes around Bursa forced more than 3,500 people to flee their homes. While firefighting teams have contained the damage to a limited number of homes across affected areas in Turkey, vast tracts of forest have been turned to ash. Unseasonably high temperatures, dry conditions and strong winds have been fueling the wildfires. Turkey and other parts of the eastern Mediterranean are experiencing record-breaking heat waves. The government had earlier declared disaster areas in two western provinces, Izmir and Bilecik. Turkey battled at least 44 separate fires Sunday, Yumakli said. Turkish President Recep Tayyip Erdogan said Monday that 99 suspects faced prosecution in relation to the wildfires. Albania fires In Albania, firefighters battled at least six separate wildfires Monday, the defense ministry said. Two weeks of blazes have ravaged thousands of hectares, or acres, of forest in the Balkan country. The areas most at risk were in the northeast, where inaccessible mountain plateaus had water-dropping aircraft carrying out the bulk of the firefighting. In the country's southern region, overnight winds ignited blazes in the municipalities of Delvine and Konispol and in the Himare district on the Adriatic coast, which suffered wildfires last week. Authorities said that at least a dozen people were arrested over the weekend over the wildfires.
Yahoo
3 hours ago
- Yahoo
Heat dome continues to raise temps across South and Midwest, will begin to move into Northeast
'Corn sweat' has increased temperatures throughout the Plains and Midwest this week. The 'heat dome' that has hovered over tens of millions of people in the South and Midwest this week is now spreading into parts of the Northeast on Thursday, according to the Weather Channel. A heat dome is a high-pressure bubble in the upper levels of the atmosphere that traps hot air and sun radiation underneath it. The Climate Reality Project, a nonprofit focused on climate change advocacy and education, compares heat domes to putting a lid on a hot pot; the lid keeps the hot air from leaving the pot and keeps the contents of the pot hot for a longer time. While late July usually is the hottest time of the year for most of the U.S., AccuWeather reports these temperatures will be 5 to 15 degrees Fahrenheit higher than the historical average. An 'Extreme Heat Watch' advisory alert, which warns 'dangerous heat is possible,' was issued for West Virginia on Thursday. An 'Extreme Heat Warning' alert, which warns 'dangerous heat is happening or about to happen,' was sent to areas in Illinois, Missouri, Mississippi, Arkansas, Louisiana, Kentucky, Tennessee, New Jersey, Delaware, Pennsylvania and New York on Wednesday. Some of these extreme heat warnings were sent to major cities like Boston, Detroit, New York City and Washington, D.C., where temperatures will reach the mid-90s by Friday, the Weather Channel reported. However, temperatures in these areas are expected to drop over the weekend. Parts of the Midwest and the South will still be in temperatures near or above 100 degrees through the rest of the weekend, and potentially into the middle of next week. Florida, which has been experiencing hot and muggy conditions across the state all week, will continue to experience high temperatures in the upper 80s to lower 90s on Thursday and Friday, according to Florida Disaster, a division of the state's Department of Emergency Management. The state's heat index values will be particularly high on the western side of the Florida Panhandle, compared to the rest of the state. (The National Weather Service (NWS) 'heat index' is a calculator that estimates what outdoor temperatures feel like to the human body.) Experts cannot determine exactly when the heat dome will end. Heat domes take a long time to break down, Bryan Jackson, a meteorologist at the NWS's Weather Prediction Center, told Scientific American, so the extreme heat is expected to last through the rest of the week for some areas. 'Corn sweat' drives up humidity in the Midwest As heat index values in the Midwest peaked this week because of the heat dome, high humidity levels have contributed to 'corn sweat' in these areas. Corn sweat is a colloquial nickname for evapotranspiration, which is when plants, like corn stalks, release water vapor into the air and essentially turn it into additional humidity that can drive up humidity levels and heat index numbers in the area, according to the Weather Channel. This mostly affects people in the Midwest, with residents in Missouri, Indiana, Iowa, Illinois and Kentucky experiencing heat index numbers in triple-digits because of the corn sweat, the Washington Post reported. The corn sweat has also affected these areas' dew points, which correlate to how much moisture is in the air, NWS explains. The higher the dew point, the more muggy and wet the air will feel. A dew point minimum of 75 equates to an extreme humidity level and feels 'oppressive, like a tropical rainforest,' according to the Washington Post. In areas affected by the corn sweat, such as southern Missouri, the dew point is at 88. Northeast, Midwest also warned about severe thunderstorms AccuWeather meteorologists alerted on Wednesday that severe thunderstorms are expected to move across the Midwest before hitting the Northeast in the next few days. These storms carry the potential for high winds and hail, according to AccuWeather meteorologists. The worst of the storms are expected to hit throughout Thursday afternoon and evening, mostly affecting cities like Chicago, Detroit, Oklahoma City and Kansas City, before shifting into the Northeast on Friday. While it's rare to see precipitation happen within a heat dome, severe thunderstorms are likely to form around its edges, often called the 'ring of fire.' "In the world of meteorology, the ring of fire deals with thunderstorms along the northern edges of strong upper-levels high,' AccuWeather meteorologist Bernie Rayno said. 'Oftentimes, this setup produces severe thunderstorms along the northern edges of the heat.' How to stay safe in extreme heat Extreme heat is the deadliest type of weather in the U.S., even more so than tornadoes, flooding or hurricanes, according to research by the NWS. Prolonged extreme heat, as is expected in the heat dome this week, is especially dangerous for people who do not have access to air-conditioning or who spend a lot of time outdoors. If you live in a place that will be affected by the heat dome, here's what to do to help protect yourself: Stay indoors and cool for as long as you can. Here is a list of public places you can go to for free air-conditioning. Stay hydrated. Adding electrolytes to your drinking water can further protect you from dehydration. If you need to go outside, protect your skin by wearing sunscreen with an SPF of 30 or higher, sun-protective clothing and UV-blocking sunglasses. Understand and look out for symptoms of heat-related illness. These include heavy sweating, fatigue, dizziness, muscle cramps, nausea and headaches. If you are experiencing these symptoms, move to a cool area to rest and hydrate. Solve the daily Crossword
USA Today
6 hours ago
- USA Today
NHC is tracking Tropical Storm Iona, 3 other systems in Pacific
While the Atlantic Ocean is calm for now, the same cannot be said of the Pacific Ocean, according to the National Hurricane Center. Forecasters are currently keeping tabs on four systems in the Pacific, including Tropical Storm Iona, the hurricane center said in a July 28 advisory. Iona, located about 915 miles southeast on Honolulu, Hawaii, has maximum sustained winds near 50 mph with higher gusts, and is expected to strengthen some in the next 48 hours, the NHC said late Sunday night. "Steady strengthening is forecast tonight and Monday, with Iona forecast to become a hurricane by Monday night," the July 27 advisory said. "Some weakening is expected to begin by late Tuesday or Tuesday night." According to AccuWeather, while no direct impacts are expected to the Hawaiian Islands, Iona will cause gusty winds that could increase wildfire risks on the islands through this week. 'Gusty trade winds can start to pick up across the Hawaiian Islands on Tuesday and can last through the end of the week and into the start of next weekend," according to AccuWeather Lead Hurricane Expert Alex DaSilva. AccuWeather forecasts that the increased trade winds combined with moderate or greater drought conditions across over half of the Hawaiian Islands will "heighten the wildfire risk," as the dry grass and vegetation will provide "plenty of fuel for any fire that sparks." There are currently no coastal watches or warnings in effect and no hazards affecting land, according to the hurricane center. Hurricane season to ramp up: Hurricane season warning signs pile up. Brace for a dangerous August. NHC keeping tabs on three other systems in Pacific The hurricane center said an area of low pressure located well east-southeast of the Hawaiian Islands is producing "disorganized showers and thunderstorms." Gradual development of this system is possible and a tropical depression could form during the next couple of days as the system moves generally westward. The NHC gives this system a 40% chance of formation through the next seven days. A second disturbance is currently located several hundred miles south-southwest of the Gulf of Tehuantepec and is producing a "large area of disorganized showers and thunderstorms," according to the NHC. "During the next day or two, an area of low pressure is forecast to form from this area of disturbed weather, well off the coast of southwestern Mexico," forecasters said in the July 28 advisory. Forecasters also said environmental conditions appear conducive for gradual development of this system, and a tropical depression is likely to form late this week as the system moves west-northwestward. The NHC gives this system a 70% chance of formation through the next seven days. Lastly, the hurricane center said a small area of low pressure has formed about 1,000 miles southeast of the Hawaiian Islands. "If deep convection persists, a short-lived tropical depression or tropical storm could develop later today," hurricane center forecasters said, giving the system a 50% chance of formation through the next 48 hours. Tropical Storm Iona tracker This forecast track shows the most likely path of the center of the storm. It does not illustrate the full width of the storm or its impacts, and the center of the storm is likely to travel outside the cone up to 33% of the time. Tropical Storm Iona spaghetti models This forecast track shows the most likely path of the center of the storm. It does not illustrate the full width of the storm or its impacts, and the center of the storm is likely to travel outside the cone up to 33% of the time. How do hurricanes form? Hurricanes are born in the tropics, above warm water. Clusters of thunderstorms can develop over the ocean when water temperatures exceed 80 degrees Fahrenheit. If conditions are right, the clusters swirl into a storm known as a tropical wave or tropical depression. A tropical depression becomes a named tropical storm once its sustained wind speeds reaches 39 miles per hour. When its winds reach 74 mph, the storm officially becomes a hurricane. Prepare now for hurricanes Delaying potentially life-saving preparations could mean waiting until it's too late. "Get your disaster supplies while the shelves are still stocked, and get that insurance checkup early, as flood insurance requires a 30-day waiting period," NOAA recommends. Gabe Hauari is a national trending news reporter at USA TODAY. You can follow him on X @GabeHauari or email him at Gdhauari@
