At 8:01 p.m. on Friday, the NWS Morristown TN released a flash flood warning in effect until 11 p.m. for Clay County.

Back-to-back flooding disasters in recent years — in Texas, New Mexico and Kentucky, among many others — have showed that preparing for flash flooding is a new necessity as the planet warms.

A flash flood is a rapid rise of water along a stream or in a low-lying urban area, the National Weather Service said. Flash flooding can result from slow-moving thunderstorms, from numerous thunderstorms that develop repeatedly over the same area, or from heavy rains associated with tropical cyclones.

An analysis of National Weather Service job vacancies found that in more than a third of offices overseeing flash flood hotspots, one or more of three senior leadership roles are open.

Straighter, smoother streams flow more violently than those that meander due to a reduction in friction. Areas with steeper terrain can see water accelerate downhill at a much faster rate causing a more destructive flash flood than flatter, open areas.

A surge of deep tropical moisture returns to Texas this weekend. Here's where the risk of flash flooding is highest in the state this weekend.

On Friday at 7:56 p.m. a flash flood warning was issued by the National Weather Service in effect until 11 p.m. for Clinton, Lycoming and Union counties.

Along with expected storms and heavy rainfall, Oklahomans could see flash flooding this upcoming weekend. Here's what to know.

Recent flash flooding in Texas​, New Mexico​ and North Carolina​ is highlighting the extreme danger of these natural disasters and the need to be prepared.