Storm supercells churned in the Great Plains Saturday and forecasters say there is a "high risk" of severe weather into Sunday in four states.

The entire population -- 200 people -- of the small Iowa town of Thurmond have been evacuated after a reported tornado struck Saturday night, damaging "most every house," John Benson of Iowa Homeland Security and Emergency Management told CNN.

Wichita was under a tornado emergency late Saturday as a large twister, part of a series of severe storms in the Great Plains, moved through south-central Kansas and threatened to destroy homes.

The "confirmed large and extremely dangerous tornado was located just east of Conway Springs and moving northeast at 35 mph," toward the Wichita area, the National Weather Service reported Saturday night. "This is a particularly dangerous situation."

Major damage to houses and buildings were likely, "and complete destruction possible," the weather agency said. But by 10 p.m. (11 p.m. ET), Kansas authorities had reported no serious damages.

Earlier in the day, a possible tornado struck a hospital Saturday evening in Creston, Iowa, according to a dispatcher with the Union County Sheriff's Department. A search-and-rescue operation was under way.

"We have been hit. We are triaging and moving patients," a spokeswoman at Greater Regional Medical Center in the south-central Iowa city confirmed.

City Council member Randy White told CNN he was aware of no serious injuries. "A lot of windows have been broken out and some cars have been flipped over. We can't see a lot right now because the power is out."

A temporary hospital was set up at Southwestern Community College, White said.

The region had more than 80 preliminary tornado reports by 10:30 p.m. ET Saturday, according to CNN meteorologist Jacqui Jeras, though some of those reports could be of the same twister. Most were in rural areas and damage was reported to be relatively minor, including downed trees and power lines and minor flooding.