EARTH-DIRECTED SOLAR FLARE AND CME:

Sunspot AR2790 is more potent than it looks. On Dec. 7th (1632 UT), the relatively small spot unleashed a C7-class solar flare and hurled a CME toward Earth. Extreme ultraviolet cameras onboard NASA's Solar Dynamics Observatory recorded the explosion:

A pulse of X-rays from the flare ionized the top of Earth's atmosphere, causing a minor shortwave radio blackout over South America (map). Affected frequencies were mainly below 10 MHz. Ironically, the flare itself was a source of strong radio emissions. Ham radio operators may have heard a 'roar' of solar static during the blackout.
UPDATE: The explosion also hurled a coronal mass ejection (CME) toward Earth. Coronagraph images from the Solar and Heliospheric Observatory (SOHO) show a halo CME leaving the sun a few hours after the flare:

Note: The bright 'stars' to the right of the sun are Mercury (top) and Antares (bottom)

NOAA analysts have modeled the storm cloud; their results confirm that it will likely reach Earth during the second half of Dec. 9th. En route to our planet, the CME will scoop up some slower-moving material from an unrelated solar wind stream. The combined impact could spark geomagnetic storms as strong as category G3, although lesser G1- to G2-class storms are more likely.
This is NOT a major space weather event. But after 3 years of uber-quiet Solar Minimum, it is noteworthy. If a strong geomagnetic storm materializes, auroras could be sighted in northern-tier US states from Maine to Montana to Washington. Stay tuned!
www.spaceweather.com