Storms on the Sun, called CMEs, eject matter and energy towards Earth...

http://www.windows.ucar.edu/spaceweather/build_storms.html
Windows to the Universe: how storms build in space.

http://www.spacescience.org/ExploringSpace/SpaceWeather/RippingStorms/1.html
A Magnetic Storm Rips Through Earth's Magnetosphere

http://hesperia.gsfc.nasa.gov/sftheory/cme.htm
Coronal Mass Ejections, Solar Flares, and the Sun-Earth Connection

http://sohowww.nascom.nasa.gov/gallery/current/19970407/
April 7-11, 1997 CME event