In the early hours of July 4, the only sound many of the vacationers along the banks of the Guadalupe River would have heard was pounding rain and thunder. They didn’t get any official warning of the rapidly rising waters that ultimately proved deadly to dozens of people swept away in central Texas flash floods.

More than 100 people have died in devastating flash floods in Kerr County, Texas. But what caused this extreme weather, and will events like this get more common?