Usually that crowd is difficult to impress, but Lee had captured its attention with the first high- resolution rendering of landspout tornadoes. These lesser-known cousins of supercell tornadoes are of interest to meteorologists now that housing subdivisions are dotting the landspout-prone Florida peninsula and the plains of northeastern Colorado. Landspout tornadoes are not as violent as supercell tornadoes, but their cumulative toll can be as great. People have witnessed as many as six funnels emerging simultaneously from a rapidly growing line of thunderstorms before weaving destructive paths several hundred meters wide and over 10 kilometers in length.

What impressed the experts during the five-minute animation wasn't just its striking imagery but also its unusually high resolution. In capturing the dynamics of these storms, Lee and Wilhelmson had developed a computer code for NCSA's CM-5 system that resolved the entire storm dynamics on a 60-meter horizontal grid (one data point every 60 meters over 10 kilometers). That resolution is almost twice as fine as the grids most often used for modeling tornadic circulations in severe storms. Severe storms -- thunderstorms, tornadoes, squalls -- are usually modeled on 3D grids on which partial differential equations for winds, temperature, pressure, moisture, and water are solved. In the landspout simulation, equations are updated every 0.4 seconds for just under an hour, resulting in billions of numbers.

Equally impressive were the massive numbers of particles modeled. Wilhelmson and Lee identified the air flow patterns within the tornadoes and storms by tracing the trajectories of some 6,500 particles. Other animations had used 50 particles, sometimes 100. Here were 65 times as many.

"I think this is what the future holds," says Wilhelmson. "Within 20 to 25 years, the National Weather Service will cover the entire globe with a fixed high-resolution grid."