OKLAHOMA CITY (CBSDFW.COM/AP) — An intense storm system moved across Texas and Oklahoma on Monday night, spawning tornadoes that caused damage and a deluge of rain but not the “particularly dangerous” twisters that forecasters had feared.

No injuries were reported.

Late Monday, the National Weather Service reduced the severe threat of violent storms to a small area of southern Oklahoma and northern Texas. But it kept an area stretching from Tulsa, Oklahoma, to Wichita Falls, Texas, under tornado watch — the level of threat just below a tornado warning — until 5 a.m. Tuesday morning

Flash flooding is threatening more 50 million people from Oklahoma to Kansas. The Oklahoma Department of Transportation shut down Interstate 40 in El Reno, about 25 miles west of Oklahoma City, because of high water Tuesday morning.

In Stillwater, emergency responders were rescuing people from their homes because of high water.

The National Weather Service had warned that Monday evening could bring perilous weather to a large swath of western Texas, most of Oklahoma and southern Kansas. The storm was expected to move later Monday into western Arkansas.

As predicted, more than a dozen sightings of tornadoes were reported in Texas, Oklahoma, Kansas, and Missouri early Monday evening, although they were in sparsely populated areas. Oklahoma residents were particularly nervous Monday because it was the sixth anniversary of a massive tornado in Moore, south of Oklahoma City, that killed 24 people.

A tornado struck western and northern portions of the southwestern Oklahoma town of Mangum on Monday afternoon. Glynadee Edwards, the Greer County emergency management director, says some homes incurred roof damage and the high school’s agriculture barn was destroyed, but the livestock survived.

“The pigs are walking around wondering what happened to their house,” she said.

Emergency officials reported a tornado near Lucien, in northern Oklahoma, severely damaging a house and destroying a barn. One storm cell near Crescent, 32 miles north of Oklahoma City, spawned twin tornadoes.

National Weather Service meteorologist John Pike in Norman, Oklahoma, said a developing layer of relatively warm air aloft late Monday afternoon and evening over central Oklahoma was capping development of the kind of supercells that spawned tornadoes earlier in the afternoon in western and northern Oklahoma. Storm cells that did develop, however, followed one after the other in what is called “training,” leading to scattered reports of flash flooding Monday night.

The Storm Prediction Center website shows the main severe thunderstorm threat Tuesday will be over Missouri and northern Arkansas, with a slight threat in a surrounding area bounded by Dallas; Springfield, Illinois; Garden City, Kansas; and Oklahoma City.

The Monday storms followed a spate of tornadoes in the Southern Plains on Friday and Saturday, leaving widespread damage and some people injured.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)