An unusually powerful spring storm dispersed a wide range of extreme weather Monday into early Tuesday, and it has not finished its assault as it barrels northeast into the Midwest. The storm’s sweeping effects have included flooding and more than 20 tornadoes in the Southern Plains.

Tornadoes and flooding in the Southern Plains

As unusually cold air pouring through the Rocky Mountains collided with warm, unstable air in the Southern Plains, violent thunderstorms erupted Monday afternoon through Tuesday morning. Forecasters had highlighted the potential for a devastating outbreak of large, long-track tornadoes, but the storms were not as bad as feared.

Even so, the National Weather Service logged more than 180 severe-weather reports, include 26 tornadoes, between northern Texas and southwest Missouri.

Oklahoma was hardest hit.

A confirmed tornado struck near Tulsa International Airport at 6:36 a.m. Tuesday. Schools in Tulsa closed, and there were reports of damage at its zoo (animals were unharmed), which was also shut down.

A large tree rests inside a home where a man was rescued in Tulsa on Tuesday morning. (Tom Gilbert/Tulsa World/AP)

Damaging tornadoes also struck near Mangum, Okla., Leach, Okla., and Paducah, Tex., on Monday.

Flash flooding proved to be more of a widespread hazard than the tornadoes. Flooding spread from the north and west sides of Oklahoma City northeast to Tulsa, where four to eight inches of rain fell in a short time. Roads were closed, and numerous high-water rescues were required.

In El Reno, west of Oklahoma City, several people, including children, were rescued from a flooded home. Schools were closed Tuesday in the city.

In addition, the Weather Service indicated Tuesday that there were “widespread” reports of flooding along Interstate 40 near El Reno, which was closed in both directions for several hours.

To the northeast, in Stillwater, Oklahoma State University and Stillwater Public Schools both closed due to floodwaters Tuesday. “Many roads are impassable, with water rescues being performed from homes,” the Weather Service tweeted early Tuesday morning.

Even though the heaviest rain has passed, flooding warnings remain in place over northeast Oklahoma as water levels are still rising along area creeks, streams and rivers.

Flooding also spread to the northeast, affecting areas of Kansas and western Missouri, which are also covered by flood warnings.

The National Weather Service predicted the Little Arkansas River in Sedgwick, Kan., just north of Wichita, would reach record high levels, 4.5 feet above flood stage.

Threat of severe weather and flooding to sweep east through Arkansas and Missouri into Tuesday night

Risk of severe storms Tuesday. (National Weather Service Storm Prediction Center)

A dangerous line of thunderstorms capable of producing damaging winds, large hail and tornadoes is expected to sweep across much of Arkansas and central and eastern Missouri on Tuesday afternoon and evening.

The National Weather Service has declared an “enhanced risk” of severe storms throughout this zone which includes Little Rock and St. Louis. A tornado watch has been issued for northern Arkansas and southern Missouri until 7 p.m. Central time.

The heavy rain associated with this storm system means a threat of flooding across almost the entire state of Missouri, which extends east into western Illinois and north into southeast Iowa, where flood watches are in effect.

In many of these areas, the ground is saturated (with soil moisture in the 90th to 99th percentile), and only small amounts of additional rain will cause flooding.

Tuesday night into Wednesday, this storm system is forecast to lift northeast through the Plains into Minnesota, dragging a cool front through the Upper Midwest, which will generate heavy showers and storms through eastern Iowa, much of Illinois, and Wisconsin.

By Wednesday night and Thursday, the storm will weaken as it pulls off into Canada.

But a new storm ejecting out of the Southwest into the Plains on Thursday could ignite a new round of severe storms from the Texas Panhandle through western Oklahoma and into Kansas.