Large and complex sunspot 3825 erupted, producing a major X4.5-class solar flare. NASA’s Solar Dynamics Observatory (SDO) recorded the extreme ultraviolet flash. A huge plasma plume is hurled out from the sun during the powerful eruption. Coronagraph images from the Solar and Heliospheric Observatory (SOHO) show a CME emerging from the blast site. NOAA forecasters have to wait for more coronagraph images to confirm any Earth-directed component.

Radiation from the flare has caused a deep shortwave radio blackout over the Atlantic Ocean and the Americas. Mariners and ham radio operators may have noticed loss of signal at all frequencies below 30 MHz for more than 60 minutes after the flare’s peak (15:29 UTC).