SEMINOLE, Okla. — Residents in the southern Plains still reeling from a deadly tornado outbreak that forecasters had warned about for days were bracing for even more storms.
The National Weather Service said a storm system that was expected to move into the Plains and parts of the Midwest on Wednesday could bring more thunderstorms, heavy rain and possibly even tornadoes to a region that saw deadly twisters two days earlier.
Scientists were able to predict almost to the hour when Monday's twisters might strike, thanks to technological advances, particularly the use of supercomputers that can crunch vast amounts of atmospheric data.
The line of storms may have spawned as many as 19 tornadoes as it marched through central Kansas and into Oklahoma, leveling houses, flipping cars and dropping hail as big as softballs. Two people were killed and dozens more injured.
"What is disheartening is to tell people for a week that something is going to happen, get warnings out and still have people lose their lives," said Dick Elder, chief meteorologist with the National Weather Service in Wichita.
Since the storms, families have been picking through broken furniture and dented appliances outside their shattered homes. Garbage trucks have been scooping up mattresses and other debris.
"We're just worried about the next round coming through and water damage," said Sara Hasley, of Tecumseh, who emerged from a neighbor's storm cellar after the violent weather earlier this week to find shingles missing from her mother's roof.
State officials, meanwhile, revised the death toll from that storm system from five to two after discovering three critically injured Cleveland County children had survived. A miscommunication occurred when relatives called a hospital to check on the children, who had been transferred, and state officials were later told they had died, said Oklahoma Department of Emergency Management spokeswoman Michelann Ooten.
The children's 27-year-old mother was killed, as was a 41-year-old man who died in southeast Oklahoma City.
Computer models can now forecast threatening storms a week or more in advance — and do so more accurately than ever.
Supercomputers at the National Oceanic and Atmospheric Administration in Camp Springs, Md., provide information sent to the Storm Prediction Center in Norman, Okla., and on to National Weather Service field offices, where warnings are issued for local areas.
"Year after year, the precision and the accuracy of those models increases," said Mike Foster, the meteorologist-in-charge at the National Weather Service office in Norman. "What we have to do is build in the minds of people everywhere that there is accuracy in those, and when they hear something seven days out, there is some meaning behind that."
In the early 1980s, computer models forecast storms two days in advance. But meteorologists still relied heavily on radar and storm spotters to confirm the location, size and strength of tornadoes.
"Comparing 20 years ago to today it is different as daylight and dark," Elder said. "We still use spotters to verify what we are seeing, but our warnings are so much more."
Despite the advance warning, many people disregarded blaring sirens Monday as three tornado-producing storms bore down on the Oklahoma City area during evening rush hour. Television station video showed motorists clogging roadways as a tornado formed at Norman.
"That looked to me like people cruising down the road there — business as usual," Foster said.
Part of the Oklahoma culture could be to blame. Tornadoes occur frequently here, and with regular TV programming often dumped in favor of storm coverage, forecasters fear people have become desensitized to the seriousness.
"I believe that if we warn too much, the message, even the frenetic message, starts to blend into the white-noise background of life," Foster said.
Misty Vestal, a relative of one of the victims, said extended warnings encourage people to take risks they might not have considered when technology was less advanced.
"I think a lot of people think they can beat it home," Vestal said.