Glenna went outside, saw hail and heard a loud boom. He ran to his basement just in time.
On Monday, he was surveying the damage on crutches after suffering a leg injury when the wind knocked his home off its foundation.
"I would say we had pretty good warning," Glenna said. "We just didn't listen to it."
Forecasting has steadily improved with the arrival of faster, more powerful computers. Scientists are now better able to replicate atmospheric processes into mathematical equations.
In the last decade alone, forecasters have doubled the number of days in advance that weather experts can anticipate major storms, said Bill Bunting of the National Weather Service.
But Bunting, forecast operations chief of the service's Storm Prediction Center in Norman, Okla. said it was not until Saturday that the atmospheric instability that turns smaller storm system into larger, more menacing ones came into focus.
That's when information from weather stations, weather balloons, satellite imagery and radar suggested there was plenty of moisture — fuel for storms — making its way northeast from the Gulf of Mexico.
Despite Sunday's destruction, 2013 has been a relatively mild year for twisters in the U.S., with the number of tornadoes running at or near record lows.
So far this year, there have been 886 preliminary reports of tornadoes, compared with about 1,400 preliminary reports usually sent to the weather service by mid-November.
Similar slow years were 1987 and 1989.
An outbreak like the one that developed Sunday usually happens about once every seven to 10 years, according to tornado experts at the National Weather Service's Storm Prediction Center in Norman, Okla.
There were similar November outbreaks in 1992 and 2002, with the 1992 one being even bigger than this year's, said top tornado researcher Harold Brooks at the National Severe Storms Laboratory, also in Norman.