More than 140 fatalities are recorded each year. Most flash flood fatalities occur at night and most victims are people who become trapped in automobiles.
Flash floods occur in mountain canyons and valleys and in normally dry washes.
They also can occur where houses or towns are built close to streams. Flash floods can pick up cars, campers and mobile homes. They can roll large rocks, knock down trees, and rip out roads and bridges. The National Weather Service says a flash flood watch means there may be flooding. Stay alert and watch for thunderstorms.