OKLAHOMA CITY – Severe storms were lashing the central United States early on May 7, after a tornado destroyed parts of two communities in Oklahoma and large hail fell in Kansas.

Earlier, the National Weather Service Storm Prediction Centre issued a rare “high risk” severe storm threat for the region, warning of intense thunderstorms with hurricane-force winds that could continue all night.

At least 15 tornadoes were reported to have struck parts of the central United States by the evening of May 6.

Seven of the tornadoes were reported to have touched down in Oklahoma, two in Iowa, two in Kansas, two in South Dakota, one in Nebraska and one in Tennessee, according to the weather service.

Baseball-sized hail fell in Kansas.

The extent of the damage was unclear, the service added, but more severe weather, possibly including more tornadoes, was expected.

A tornado took out about one-third of the small city of Barnsdall in north-east Oklahoma, destroying or damaging buildings and injuring multiple people who were hospitalised in about 20 ambulances, said Mr Jerry Roberts, the emergency management director in Osage County.

The tornado also lifted the roof off a nursing home in Barnsdall, said Mr Steven Cobb, a meteorologist for the weather service office in Tulsa, Oklahoma.

As the storm bore down, the weather service issued a rare tornado emergency alert, which warns of catastrophic damage and severe threat to human life, for about 30 minutes in part of Osage County and Washington County in Oklahoma.

The tornado destroyed power lines along its path, leaving entire towns without electricity, Mr Cobb said.

It touched down near Barnsdall about 9.30pm and moved north-east towards Bartlesville, until it lifted off the ground there at about 10.15pm, he said.

Barnsdall was also hit by a tornado in April, but the May 6 tornado appeared more powerful, estimated to be a 2 on the Enhanced Fujita scale, which goes from 0 to 5, Mr Cobb said.

In Bartlesville, the worst damage was in the city’s south-west and north-east sides, said Mr Kary Cox, the director of Washington County Emergency Management.

Emergency responders rescued trapped individuals in a Hampton Inn and were recovering downed power lines early May 7, the city of Bartlesville said. The city said that minor injuries had been reported, without stating how many.

More than six million people across parts of Oklahoma, Kansas, Iowa, Missouri, Nebraska and Texas were under tornado watches early on May 7.

About 12.15am local time, the weather service issued a tornado warning for Oklahoma City and the area east of it.

“This is a particularly dangerous situation,” the weather service said in the late afternoon of May 6 on social media of the tornado threat in Oklahoma.

In Garfield County, Oklahoma, severe weather destroyed some barns, felled trees and sent cars hydroplaning into ditches, but no one was injured, said Mr Mike Honigsberg, emergency management director for the county.

The Storm Prediction Centre, which is part of the weather service, predicted its highest risk level for the first time since March 31, 2023. On that day, 131 tornadoes formed across 11 states from the Midwest to the South.

The last high-risk level for Oklahoma was May 20, 2019, when 35 tornadoes spawned across five states, mainly in the Plains.

Forecasters raised the risk level on the morning of May 6 as the conditions across the Plains evolved, increasing their confidence that multiple significant tornadoes along potentially long paths will occur.

“Anybody in the affected areas should have a safety plan,” said Ms Kelly Butler, a meteorologist in the Wichita, Kansas, office of the weather service.

The weather service described the environment in southern Kansas and into Oklahoma as being “similar to some past higher-end, and even historic, severe weather and tornado events”.

A possible flood risk could also occur, as heavy rain increases over parts of eastern Kansas and Nebraska, as well as western Iowa and Missouri, as a front moves out of the Rockies, according to the Weather Prediction Centre.

The Weather Prediction Centre warned of a slight risk of excessive rainfall over parts of the Central Plains and Middle Mississippi Valley from May 6 into the morning of May 7.

The heavy rain could produce flash flooding in urban areas, roads, small streams and low-lying areas.

The severe weather risk comes a week after more than two dozen tornadoes were reported and at least five people were killed in Oklahoma and Iowa, including an infant, the authorities said.

The current threat did not end on May 6. More storms are forecast for the next couple of days, primarily on May 8, from Texas to Ohio. NYTIMES