STRONGEST FLARE OF 2016: Sunspot complex AR2565-AR2567 erupted on July 23rd, twice, producing two strong solar flares in quick succession. The first @ 0211 UT registered M5 on the Richter Scale of Flares. The second @ 0516 UT registered M7.6, making it the strongest flare of 2016 so far. NASA's Solar Dynamics Observatory recorded the blast:

Pulses of radiation from the two flares ionized the top of Earth's atmosphere, causing a blackout of shortwave radio transmissions over the Pacific side of Earth. These maps from NOAA show the frequencies and territories affected. People who might have noticed the fading signals include ham radio operators, mariners and aviators.

Update: The explosions hurled an impressive CME into space: movie. The body of the cloud will not hit Earth. However, Earth could experience a glancing blow from shock waves on the outskirts of the cloud. This has prompted NOAA forecasters to issue a minor geomagnetic storm warming for July 26th when the shocks might arrive. Aurora alerts: text or voice

http://spaceweather.com/