(AP) - Researchers working on ways to improve weather forecasting unveiled a new $17 million supercomputer Wednesday that will be able to make five trillion calculations per second. "This is a huge step forward," said A. E. "Sandy" MacDonald, director of the government's Forecast Systems Laboratory in Boulder, Colo., where the new computer is installed. "We think it's going to make weather forecasting in the coming years much better," MacDonald said of the supercomputer called JET. MacDonald's lab, part of the National Oceanic and Atmospheric Administration, studies weather forecasting and develops computer models and methods for use in day-to-day forecasting by the National Weather Service.