OKLAHOMA CITY  — As the nation’s midsection braces for another bout of severe weather, many residents in Oklahoma are still reeling from a rare combination of tornadoes and flash flooding spawned from the latest round of thunderstorms that rumbled across the state.

Conditions appeared to be ripe on Friday and Saturday for storms that could produce even more powerful tornadoes across an area covering southern Kansas, western Oklahoma and parts of North Texas, said meteorologist John Hart of the Storm Prediction Center in Norman.

More storms with rain, hail and tornadoes are also forecast in eastern Nebraska, while people living in the state’s west, along with South Dakota, might have to dust off their snow shovels.

The National Weather Service has forecast 3 inches to 5 inches of weekend snow in the Nebraska Panhandle and about 6 inches to 12 inches for South Dakota. Meteorologist Rob Cox said snow is not uncommon in Nebraska in May and even June.

Storms that spawned 51 tornadoes in several southern Plains states late Wednesday brought torrential downpours in central Oklahoma so heavy that a 43-year-old Oklahoma City woman drowned after becoming trapped inside her underground storm cellar.

“It just flooded with her in it, and she couldn’t get out because it was like a river coming down on top of her,” said police Sgt. Gary Knight. “I don’t recall it ever raining like that before.”

Skylyna Stewart’s body was discovered in an older, underground shelter detached from the home, and Knight and other emergency management officials said such cases are extremely rare.

The 7.1 inches that fell in Oklahoma City was the third highest rainfall for any day on record, dating back to 1890, said state climatologist Gary McManus, and radar data from the southeast part of the city where Skylyna Stewart’s body was recovered indicated as much as 8 to 12 inches may have fallen.

“Part of the problem was that we had gotten a lot of rain earlier,” McManus said. “The soils were moist, and the rain had nowhere to go.”

A few miles away in Moore, Kelly Ruffin said she and her family took shelter from the storms in an underground shelter installed in their garage when water from the heavy rains began leaking in.

“It was a heavy trickle at first, and within about 10 or 15 seconds, it was gushing,” Ruffin said. “We had to decide if we were going to stay down there and drown or get out, because the sirens were going off. We decided to get out.”

Blake Lee of F5 Storm Shelters & Safe Rooms has been installing shelters in Oklahoma for nearly five years and described the drowning as a “really, really freak deal.”

“It was a flash flooding situation, and we got more rain yesterday than we typically get in a month,” Lee said. “The underground garage model, to this day I’ve never heard of anyone dying in them.”

Blake said it’s not uncommon for an underground shelter to leak, and he encouraged people who have one to check them every few months to make sure they’re not filling up with water.

“If you’ve been doing this long enough, you’re going to have shelters that leak. It can happen,” he said. “But it’s a really easy fix.”