The sun has been very active this week, causing major geomagnetic storms as a large sunspot group crosses the sun's face.
In the past several years the study of solar weather (more importantly, "Space weather" in the region of space around the Earth) has been recognized as an important area of study. Storms on the sun release large amounts of radiation and energetic particles, both of which can and have damaged satellites. With our growing use (and, dare I say, dependence) on satellites, from weather to GPS to phone calls, it is clearly important to learn to predict "space weather."
Space weather is also important for astronauts and cosmonauts on the International Space Station. Inside the station they are safe, but they cannot safely go outside during these storms. The radiation also affects Earth's upper atmosphere, making radio communications (such as military and jet aircraft radios) difficult if not impossible, especially near the poles. On the good side, solar storms make aurora (the "Northern Lights"), which are quite beautiful.
If you'd like to follow space weather, the Space Environment Center has more information than you could care to find!