The trouble with tornado tracking

Tornadoes and hurricanes may have swirling destruction in common, but when it comes to forecasting, the storms could not be more different. Due to their large size and longevity, hurricanes can be tracked for weeks in advance. Tornadoes, on the other hand, are relatively small and short-lived. Even with today’s advanced tracking technology, communities in a twister’s path often only get a few minutes’ warning.

The problem with tracking tornadoes doesn’t necessarily lie in storm detection. Doppler radar and satellites have greatly improved since the days when tornado alerts relied on eyewitness accounts. But challenges arise in creating and running computer programs to model how storms might form and evolve over time.

At NOAA’s National Severe Storms Lab (NSSL) in Norman, Okla., which focuses on tornadoes, hail and high winds, the computation problems break down into issues with size, scale and speed.

Studying the storms that give rise to tornadoes requires extremely high-resolution observational data, which is then plugged into weather models that often can’t quite grasp the strange physics of highly volatile storm systems, says Ashton Robinson Cook, a meteorologist at NOAA’s Storm Prediction Center, also based in Norman, Okla.

At the fine scales needed for accurate weather prediction, these models can only be run on the fastest supercomputers. But that still takes time. While all that computing is going on, a storm may be rapidly evolving into something dangerous; with existing technology, the average time to detect, track and release warnings on a developing storm system or tornado is 14 minutes.

Researchers at the NSSL are hoping to increase that lead time to as much as an hour, Cook says, by looking beyond supercomputers to systems based on graphical processing units, which would greatly increase the efficiency and computing power.

Other goals, Cook says, include increasing the number and resolution of weather radar stations around the country (right now, 70 percent of the U.S. has inadequate radar coverage) and continuing to improve scientists’ knowledge about the physics of how storms form and evolve into deadly and destructive tornadoes.

Mary Caperton Morton
Monday, April 2, 2012 - 12:00