The picture above is taken from the NASA run SOHO spacecraft which shows an image of a helical shaped Coronal Mass Ejection coming from the Sun. This shape of ejection is rare. Coronal Mass Ejections are nothing more than pieces of the Sun ejected from the main body of the Sun and thrown into Space. When this happens it usually does not happen on a small scale. Upwards of 10 billions tons of coronal mass at a time can be thrown into space. These 10 billion tons of material is made up primarily of Protons, or hydrogen stripped of all its electrons. When these protons reach earth as they sometimes do they are responsible for a great many different terrestrial events. Some of these events include power blackouts, aurora borealis, radiation hazard to astronauts, interuppted cellular phone converations, increased static on UHF television stations, and many many others.
Currently scientists have several different methods to try to predict when and where these coronal mass ejections (CME) will occur on the Sun. Both aspects of this prediction are important. Only CME's coming from certain parts of the Sun will actually be thrown towards the Earth. So obviously where on the Sun the will occur is important. The prediction of when they will occur is very important as the Sun is constantly rotating. So if you only know the area of the Sun an ejection will occur from it isn't as useful as knowing the area and the time, as the area is constantly rotating. Once both of these have been established steps can be taken, if enough lead time on an Earth-bound CME can be achieved, steps can be taken to limit the Terrestrial effects.
Current prediction techniques take on various forms, some optical some in other wavelegths. The one currently being explored here at The University of North Texas is utilizing high resolution radio "maps" of the sun, and complete spectra. These two things are looked at for the change in radio flux vs. the change in time to attempt to make accurate predictions for when and where a CME will take place.