And another source for Space Weather; Solar Flares!

A solar flare is a bright flash of X-rays seen during an energetic explosion in an active region of the Sun. It's usually seen as a large burst of X-rays, but may also have a coincident bright flash of white light. A flare lasts a matter of minutes but releases an immense amount of energy. During solar flares the Sun can be 1000 times brighter in X-rays than normal.

Flare intensities are categorized by NOAA NWS Space Weather Prediction Center (NOAA SWPC) based on the X-ray flux measured at Earth. Large X-ray flares can cause greatly enhanced levels of ionization of the Earth's ionosphere that can cause problems for radio communications as well as certain types of low-frequency navigation.

Here is a X1-class solar flare from June 11, 2014.

Credit: NASA Solar Dynamics Observatory (Little SDO)