The downpour marked the latest such flood that has occurred over the past few weeks across the United States. In one week alone, three 1-in-1,000-year rain events occurred — inundating St. Louis, eastern Kentucky and southeastern Illinois. The term, often considered controversial in part because it’s misunderstood, is used to describe a rainfall event that is expected once in every 1,000 years, meaning it has just a 0.1 percent chance of happening in any given year. But such events can occur more than every thousand years.

Human-driven climate change has been found to increase the frequency of such high precipitation events — a warmer atmosphere, capable of holding more moisture, can produce heavier rain. According to the Intergovernmental Panel on Climate Change’s 2022 report, the rate of extreme precipitation events that cause severe flooding is expected to increase in the future.

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Fox Weather reporter Robert Ray, who was reporting on the flooding in Dallas, found himself rescuing a woman who accidentally drove into a flooded intersection.

“She literally, as I was standing here setting up for the shot, guys, pulled in and didn’t realize it,” Ray told Fox Weather. “The next thing you know, her car was floating. So, I went out there and tried to push her vehicle as best I could.”

Several water rescues were ongoing Monday across the Dallas-Fort Worth area. As of 8 a.m. local time, Dallas Fire and Rescue had responded to 141 water-related emergencies, according to Jennifer J. Moreno, a spokesperson with the city’s emergency management office. By 10 a.m., the Fort Worth Fire Department was responding to 25 high water rescue calls, and Dallas police were responding to an additional 43 “high water calls.”

Jeff Lindner, a meteorologist for Harris County, Tex., noted on Twitter that one weather gauge recorded nearly 40 percent of its typical annual rainfall in just 12 hours.

Later Monday morning, that same gauge tallied over 14.9 inches of rain, still within 12 hours.

Such rates of precipitation are nearly impossible for soils — not to mention impervious paved surfaces — to absorb without runoff that can cause flash flooding.

Water levels at Trinity River in Dallas are expected to enter minor flood stage Monday into Tuesday. Flooding is also occurring in Balch Springs, a suburb of Dallas, where a grass fire earlier this summer damaged more than two dozen homes.

A communications outage caused by a Verizon line problem has prevented the National Weather Service from issuing warnings from the Fort Worth office, the NWS confirmed to The Washington Post, though the office says it is still working closely with partner offices to stay on top of the flooding.

“While Verizon works to fix the issue, long-and short-range forecasts and warnings for the Dallas-Fort Worth area continue to go out uninterrupted, through service backup by our forecast offices in Nashville, Tennessee, and Norman, Oklahoma,” said Susan Buchanan, the NWS’s Director of Public Affairs.

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After the flooding rains move out of the Dallas area, they are expecting to continue to track along Interstate 20 toward areas such as Shreveport, La. The National Weather Service’s Weather Prediction Center has issued a moderate risk of excessive rainfall for northeastern Texas and northwestern Louisiana, with 3 to 5 inches of rain expected in the area and rates of 2 to 3 inches per hour possible.

More excessive rain is expected Tuesday, with the moderate risk for heavy rainfall spreading farther across northern Louisiana into parts of Alabama.

Before Monday’s intense rainfall, the Dallas-Fort Worth area was in the midst of a substantial drought. All of Dallas County has been experiencing at least extreme drought for the past three months, according to the U.S. Drought Monitor.

At one point, Dallas had dozens of days above 100 degrees and 67 days in a row without any rainfall, a streak that was finally broken Aug. 9. Now, in a shocking reversal, it is likely that this August will be Dallas’s wettest since 1899, the Weather Channel’s Jim Cantore noted on Twitter.

Cities across Texas experienced near-record-high temperatures and dryness last month, causing serious precipitation deficits. But the heavy rainfall over parts of the state into Monday may not bring enough relief, the NWS warned.

The heavy rainfall across Texas, Arkansas, Louisiana and Oklahoma stems from an overlap of extreme moisture and a forceful triggering mechanism.

Over the weekend, an underwhelming tropical system moved ashore in northern Tamaulipas, Mexico, with relatively little fanfare. Its direct impacts were minimal, but it trucked ashore an air mass replete with deep tropical moisture. PWATs, or precipitable water indexes — a measure of how much moisture is present in a column of air from the bottom to the top of the atmosphere — are approaching a remarkable three inches.

That’s the air wafting north into thunderstorms and being converted into heavy downpours along a stationary front. The front is draped west to east near the Red River of Oklahoma toward the Arkansas-Louisiana border. A wave of low pressure that is forming along the front and propagating east will further enhance those downpours. Some locations will see a low-end tornado risk, too.

When flooding struck the Dallas area, parts of north-central and northeastern Texas were under flood watches — an alert level that is below flood warnings — until noon Central time Monday, including Dallas, Rockwall and Delta counties. The NWS warned of “rainfall totals of 2 to 5 inches, with isolated amounts in excess of 8 inches.”

Local news outlets and reporters shared videos of a water rescue on a flooded highway in the Dallas area. People swam in murky floodwaters, their vehicles abandoned on roadsides with their alarms blaring.

Matthew Cappucci contributed to this report.