X1-CLASS SOLAR FLARE: This comes as no surprise. Behemoth sunspot AR2192 has unleashed an X1-class solar flare. NASA's Solar Dynamics Observatory recorded the blast in this extreme UV image of the sun on Oct. 19th (0500 UT):
A pulse of ultraviolet and X-radiation from the flare caused a brief but strong HF radio blackout on the dayside of Earth, mainly over Asia and Australia. Also, the explosion probably hurled a CME into space. This possibility has not yet been confirmed by SOHO coronagraph data. If a CME is forthcoming, it will probably sail wide of Earth due to the sunspot's location near the sun's eastern limb.
Big sunspots tend to produce big flares, and clearly AR2192 is no exception. More X-flares are likely as AR2192 turns toward Earth in the days ahead. Also, if you have a solar telescope, point it at the sun. This active region is a real beauty.