The heavy rain that turned a river in Texas into a raging wall of water was fueled by unique atmospheric conditions, according to meteorologists and climate scientists.

As a succession of thunderstorms fed by the remnants of Tropical Storm Barry pummeled Texas' Hill Country, tools used by the National Oceanic and Atmospheric Administration to detect extreme rainfall began “maxing out the color charts.

"These are roughly one-in-1,000-year events, [and] would be extremely rare in the absence of human-caused warming,” one climate scientist says.

Heavy rains fell quickly in the predawn hours of Friday in the Texas Hill Country, causing the Guadalupe River to rise 26 feet in just 45 minutes.

Meanwhile, anguished parents waited for word on the 10 young campers still missing from Camp Mystic, which was hit hard by floodwaters.

The Gulf, which borders Texas, has become significantly warmer in recent years due to climate change, Swain explained. This results in a very warm body of water that produces a lot of evaporation, releasing more tropical moisture into the air than seen historically.

There was little indication of how torrential the Texas downpours would become before dawn. At least 27 people were killed, many of them children at Camp Mystic.

Texas Hill Country is no stranger to extreme flooding. In the rugged, rolling terrain it’s known for, heavy rains collect quickly in its shallow streams and rivers that can burst into torrents like the deadly flood wave that swept along the Guadalupe River on July 4.

Some regions in the mid-Atlantic are also facing risks of flooding. On Sunday, Tropical Storm Chantal flooded parts of North Carolina, where more than 10 inches of rain fell near the Chapel Hill area. The Haw River, near Bynum, North Carolina, crested to nearly 22 feet, the highest crest on record there, as a result of those heavy rains.

Last week’s devastating Hill Country flooding is likely to feature heavily in a Wednesday hearing on President Donald Trump’s nomination of Neil Jacobs

The National Weather Service extended a flood watch July 7 through 7 p.m. local time for much of central Texas.