On July 2 (23:14 UT), giant sunspot AR3354 exploded, causing a prolonged X1-class solar flare. The radiation from the flare ionized the upper atmosphere of the Earth. This caused shortwave radio communications over the western parts of the United States and the Pacific Ocean to shut down. Sailors and radio amateurs could notice signal loss and other propagation effects for more than 30 minutes after the flash.
Although the explosion lasted long enough to lift the CME (coronal mass ejection) out of the Sun’s atmosphere, this does not appear to have happened.
The cause of this outburst is interesting and unusual. The sunspot did not explode on its own. It was helped by a plume of plasma swirling over the edge of the sun. Hot, magnetized gas hitting the sunspot caused the explosion.