The sun has emitted the strongest solar flare so far this year, an event shortly followed by a coronal mass ejection (CME).

The solar flare took place at 3:16 a.m. EDT on Thursday April 11 as a M6.5-class flare, temporarily causing a radio blackout on Earth, according to NASA.

"This is the strongest flare seen so far in 2013," NASA spokeswoman Karen Fox said in a statement. "Increased numbers of flares are quite common at the moment, since the sun's normal 11-year cycle is ramping up toward solar maximum, which is expected in late 2013."

Solar flares are bursts of radiation. Though they cannot physically influence humans on Earth, they can disrupt radio signals in the atmosphere above the planet. The M-class flare seen on Thursday was about 10 times less powerful than X-flares, the strongest solar flares emitted by the sun. M-class flares are the weakest solar flares that still interfere with communications near Earth.

CMEs are solar phenomena whereby the sun emits billions of tons of solar particles, possibly affecting satellites and electronic systems on Earth. CMEs that move toward Earth can result in a geomagnetic storm, an event whereby the CME interacts with the Earth's magnetosphere. Thursday's CME began at 3:36 a.m. EDT. It was measured to be traveling from the sun at 600 miles per second and should reach Earth in the early morning hours of Saturday April 13. A CME from the sun was also reported on Friday March 15.

The solar flare and CME were also paired with a solar energetic particle (SEP) event near Earth. SEP events are the result of fast-moving protons and charged particles moving toward our planet and have the potential to disrupt high frequency radio communications.

NASA, NOAA, the U.S. Air Force Weather Agency (AFWA) and other agencies constantly monitor the sun to watch for space weather events. Many spacecraft and satellites are protected from the effects of these events through advance notification.