ULYSSES ? Powerful thunderstorms spawned two dozen tornadoes in southwest Kansas in less than two hours Thursday, damaging a hospital roof and downing fences and sheds.

Many of the tornadoes were weak, and no injuries were reported as they touched down in a corridor roughly 20 miles wide and 110 miles long from near Ulysses in Grant County to north of Protection in Comanche County.

At one point just before 5 p.m., storm chasers reported two tornadoes moving on either side of U.S. 283 in Ford County, about 20 miles south of Dodge City.

Two minutes later, a trained spotter in Ford County reported a separate tornado with a debris cloud estimated at one mile wide.

Nine patients at Bob Wilson Memorial Hospital in Ulysses were moved to other rooms after a layer of the roof over the intensive care unit was blown off about 4:30 p.m., hospital officials said. An older wood roof remained in place, but crews covered it with tarp to prevent water damage.

Staff at the National Weather Service in Dodge City tallied 24 separate tornadoes in all from 3:50 p.m. to 5:40 p.m.

The outbreak was fed by the same weather system that brought heavy snow to eastern Colorado. Forecaster Jennifer Ritterling, of the weather service bureau in Dodge City, said tornado outbreaks sometimes hit the Plains in September and October when conditions are right.