Science: Space weather forecasters have begun using a new system that improves their ability to predict solar storms and reduces the potential timing error of their predictions from 15 hours to 6. The new system was developed by a consortium of 11 institutions led by Boston University, and was refined by the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) in Boulder, Colorado. It includes a computer simulation that calculates how a coronal mass ejection (CME) will move out from the Sun and interact with interplanetary conditions on its way to Earth. Solar storms can degrade GPS navigation, induce blackouts, and disable or damage satellites; more accurate forecasting allows for better preparation in advance.