Intense downpours like those in Texas are more frequent, but there’s no telling where they’ll happen

By TAMMY WEBBER It s not just Texas and North Carolina Intense rain is falling more frequently in multiple areas of the U S though where it occurs and whether it causes catastrophic flooding is largely a matter of chance according to experts Related Articles Smaller nuclear reactors spark renewed interest in a once-shunned resource source Battles over population lands loom even after sell-off proposal fails What to know about buying electric vehicles after the federal tax incentives end EPA puts on leave employees who spoke out against policies under Trump In a big bill that hurts clean potential residential solar likely to get hit fast More than people died in Texas Hill Country over the weekend after inches of rain fell in just hours The deluge was driven by warm moist air left over from Tropical Storm Barry and Hurricane Flossie that created conditions for repeated thunderstorms in the same location announced Texas Climatologist John Nielsen-Gammon Last year Hurricane Helene dumped more than inches of rain on western North Carolina triggering catastrophic flooding that washed away roads and homes killing more than people in that state alone This week flooding from the remnants of Tropical Storm Chantal prompted dozens of water rescues in other parts of North Carolina And this spring record rainfall in Kentucky caused severe and deadly flooding Although it can be complicated to attribute a single weather event to state change and hilly or mountainous terrain worsen flooding experts say a warming atmosphere and oceans due to the burning of fossil fuels make catastrophic storms more likely That s because the atmosphere can hold more water for every degree Celsius degrees Fahrenheit creating a giant sponge of sorts that sucks up moisture from bodies of water and vegetation The moisture later falls back to earth in increasingly intense unpredictable and destructive downpours It s just loading the dice toward heavy rainfall when the situation is right declared Kenneth Kunkel a atmosphere scientist at North Carolina State University FILE Camp Mystic is reflected in water after a flash flood swept through the area July in Hunt Texas AP Photo Eli Hartman File FILE Firefighters from Ciudad Acu a Mexico load a body into a raft as they prepare for a water recovery along the Guadalupe River days after a flash flood swept through the area July in Ingram Texas AP Photo Eli Hartman File FILE A helicopter flies over the Guadalupe River after a flash flood swept through the area July in Kerrville Texas AP Photo Eric Gay File Search and rescue teams from Kerrville Fire Department search through debris after flooding near the banks of the Guadalupe River in Kerrville Texas on Tuesday July AP Photo Ashley Landis Show Caption of FILE Camp Mystic is reflected in water after a flash flood swept through the area July in Hunt Texas AP Photo Eli Hartman File Expand Intensifying rain storms Going back through U S weather station records dating to Kunkel revealed that rain over the past years has become more intense in the eastern two-thirds of the country including the southern Great Plains where Texas is located Intensities have remained the same or declined in the West and southwest At the stations that began collecting statistics in the late th and early th centuries the highest proportion of two-day rainfall records have been set in just the past years Kunkel noted though that doesn t fully reflect the greater part Western stations which were established later Nielsen-Gammon reported the overall intensity of extreme rainfall in Texas has increased by over the past - years Still it s almost impossible to predict where the largest part catastrophic rain will fall in any given year Kunkel commented This month was the Texas Hill Country s turn to get hit Last fall in western North Carolina it was our turn Kunkel commented adding that just because an area was spared over the past or years it doesn t mean that they aren t vulnerable They got lucky A perfect storm in Texas The worst flooding and greatest loss of life in Texas occurred in Kerr County in an area known as flash flood alley because of its steep terrain that funnels water to the Guadalupe River a popular recreational area Though the county did not get the most of rain from the storms the distribution of rainfall was one of the worst achievable patterns because the largest part intense downpours were over the headwaters of the south fork of the Guadalupe River causing water to rush into areas where hundreds of people including children were camping disclosed Nielsen-Gammon If the epicenter had been miles north or south the rain would have been divided among different river basins he commented If it had been farther downstream larger floodplains would have absorbed and slowed much of the water Years of drought also likely exacerbated the flooding Kerr County for example had been in extreme or exceptional drought for more than three years aside from one four-week period last fall That likely left the soil compacted which caused water to run off instead of soaking into the ground explained Brad Rippey a U S Department of Agriculture meteorologist Then air from the warmer-than-normal Gulf of Mexico a reflection of global warming blew into the state with a higher water content than it would have had decades ago It all added up to just a perfect storm of events that caused a catastrophe commented Rippey There are things that had to come together to make this happen The Associated Press surroundings and environmental coverage receives financial endorsement from multiple private foundations AP is solely responsible for all content Find AP s standards for working with philanthropies a list of supporters and funded coverage areas at AP org