When the tornado sirens began to wail near the home of Oklahoma City meteorologist Harold Brooks the evening of May 3, his seven-year-old daughter knew just what to do. "We need to go to Shelby's," she told her parents. Shelby was not just a classmate -- her home also was one of the few in the neighborhood with a basement. Although his neighborhood emerged from the storm unscathed, Brooks said his daughter embodied the hopes of forecasters nationwide -- she heeded the tornado warnings and knew exactly what to do.
Forty-eight people lost their lives in the deadly spate of tornadoes, but there were no deaths among people aged four to 24. "No school children died," Brooks said. "The probability of that happening is less than 1-in- 1,000."
Brooks, who is the head of the Mesoscale Applications Group at the National Severe Storms Laboratory (NSSL) in Norman, Okla., said the kids learned tornado preparedness in school -- a valuable lesson, as it turned out. While the predictions, forecasts and warnings issued during the storm system were unprecedented in their timing and accuracy, they would have been useless if the community didn't know how to respond.
According to Brooks, an estimated 684 people would have died May 3 without the tornado warnings and the community's response to them. The tornadic assault on Oklahoma City and its surrounding suburban communities was the most expensive on record, with damages expected to top $1 billion. One of the tornadoes produced the most powerful winds ever recorded on earth. According to Brooks, a radically violent storm tearing through a heavily populated area is a once in a century event. But the research coverage, the forecast and warning systems, and the communications efforts that surrounded the storm were also historic -- never before had they combined their efforts so effectively.
"There was a very strong interaction between researchers, the forecasting communities and the media," Brooks said. "Communication was phenomenal and the media was pervasive -- 76 percent of area households tuned in to their televisions or radios to get reports." According to Brooks, the culmination of 50 years of research and science saved hundreds of lives. "There was a big payoff of basic research, operational meteorology, and the media getting the word out," he said.
Of all the spots in the country for a violent tornado to strike, Oklahoma City is probably the most prepared. In the heart of Tornado Alley, residents are used to watching the skies and listening to forecasts during a stormy spring evening. Fittingly, many of the world's leading storm scientists are based in the region.
In addition to the NSSL, there is a team of renowned meteorological research scientists at the University of Oklahoma, which is also home to the Oklahoma Weather Center and the Center for Analysis and Prediction of Storms (CAPS). On May 3, the meteorological event of their careers took place, and right in their own backyards.
Fifteen years ago, President Ronald Reagan decided America had lost its edge in scientific investigation and he set about creating a national system of science and technology centers to be headed by the National Science Foundation (NSF). In 1989, CAPS was established at the University of Oklahoma as one of the NSF's first 11 Science and Technology Centers.
Its formal mission is to "demonstrate the practicability of storm-scale numerical weather prediction and to develop, test and validate a regional forecast system appropriate for operational, commercial and research applications." Its ultimate vision is to create a storm prediction system that can forecast the timing, location and intensity of a storm. According to Kelvin Droegemeier, cofounder and director of CAPS, the work of the scientists he has been leading for the past decade is now beginning to bear fruit.
The centerpiece of their research is a new three-dimensional modeling system known as the Advanced Regional Prediction System (ARPS) -- a numerical prediction system designed to explicitly represent storms in a computer model. To generate the models, the researchers first gather wind, temperature and humidity information from a host of observation systems, including weather balloons, satellites, surface networks, Doppler radar, even commercial aircraft.
After they collect the data they input it into computers and break the atmosphere into a representational cube in which they solve billions of equations a minute to account for the rapidly unfolding weather conditions. With extremely fast supercomputers, the researchers are able to capture the structure of a maturing storm and make predictions of how the storm will take shape.
Droegemeier said just five years ago it would have been considered impossible, but on May 3 he and his team of scientists were able to predict the strong likelihood of violent tornadoes two hours in advance. After recording, inputting and updating conditions, the researchers created models of the storm and saw the development of the mesocyclone -- the strong rotating updraft of a supercell thunderstorm, the kind of storm that produces violent tornadoes. Although the system didn't pinpoint the exact location of the storm, watches and warnings were issued for the entire area and the media was able to alert the greater community.
The current state of technology is indeed exceptional, but meteorologists still don't know what happens within the first few minutes of a storm. "We don't know what occurs just before a tornado develops. The best we can do at the moment is forecast three to six hours in advance that the conditions that produce tornadoes are developing," said Droegemeier. "The challenge is to capture the initiation of the storm -- to track where it begins."
That challenge may be overcome sooner than expected thanks to data gathered by Doppler Radar on May 3. Three Doppler-on-Wheels vehicles were deployed during the storm and their high resolution recordings provided unprecedented detail of tornado formation.
The vehicles were in the field collecting ordinary observations -- such as temperature, winds, humidity and pressure -- when the storms struck. One tracking unit watched a tornado being born. But that wasn't the evening's only radar first. Another vehicle recorded an image of several small tornadoes spinning inside the vortex of a massive funnel -- data that will teach researchers a lot about tornado "families." Still another reading taken by a Doppler-on-Wheels measured wind speeds of 318mph, the strongest wind speed ever measured on the ground. This tornado, which flattened the city of Moore, was at the highest end of the Fujita scale, which ranks twisters on a scale of one to five. If the monster tornado had been just 1mph faster, it would have entered the mythical realm of an F-6, which has never before been recorded and as such isn't part of the Fujita scale.
According to Brooks, the Holy Grail of storm researchers and forecasters is predicting the intensity of a tornado, but the data collected by Doppler on May 3 will bring them much closer to discovering what goes on inside a storm just before it spawns a tornado. This data is crucial for reducing the number of false alarms.
One of the main functions of the Storm Prediction center in Norman is to improve the quality of forecasts. "We need credibility," said Brooks. "We need people to believe the message and heed the call when we issue a tornado warning." Otherwise, their estimate of more than 600 lives saved on May 3 could be the actual death toll the next time a twister rages through a densely settled area.