According to the National Weather Service, a flash flood is flooding that begins within six hours, and often in as little as three hours, of heavy

At least 24 people have died and about 20 children are missing after a catastrophic flash flood in Texas. The Guadalupe River that runs through Hill Country in central south Texas rose by 26ft (8 metres) in just 45 minutes in the early hours of Friday, according to officials, bursting its banks and damaging roads and property.

Heavy rains caused devastating flash floods in the Texas Hill Country, killing at least 24 people and leaving many others missing.