Storm forecasting is still a messy field, and without meterologists being able to predict exactly where a stom is going to hit, it's hard for computer researchers to determine what the storm will do to a city when it hits. Even as more money and better data-gathering techniques are employed to track and predict hurricanes, deciding when and where a storm will hit is still a woefully imprecise science. Luettich points out that in a city like, say, New Orleans, officials would want to know the impact of a storm days--or even weeks--in advance. There are plans to be made: evacuation buses to be lined up, people to be prepped. But although storms can be predicted with more certainty the closer they move to the mainland, at five days out, it's still only a best guess. "Truthfully, at five days out, you could go from a situation where you had major impacts to a situation where you had no impact at all," Luettich says.