Space Forecasting Center Space weather forecasts and alerts are issued by NOAA's Space Environment Center (SEC), located in Boulder, Colorado. SEC receives space weather data from many different satellites and ground-based stations around the world. Forecasters track Sunspots, map coronal holes and provide a detailed description of all active regions visible on the solar disk. The face of the turbulent Sun, as seen here in Hydrogen-alpha wavelengths, is far more violent than most people suppose. Hydrogen-alpha is an absorption line of neutral hydrogen in the red part of the visible spectrum. It is used to characterize solar flares, filaments, prominences, and the fine structure of active regions. (click here to learn more about these features) Sunspot Groups, like those seen as dark areas in visible-light images of the Sun, are also responsible for X-ray emissions. These are active regions where hot, dense plasmas are energized. They are also associated with regions of oppositely directed magnetic fields which can erupt as a solar flare and coronal mass ejection.