Active sunspot 1401 erupted today, Jan. 19th, between 15:15 and 16:30 UT. The long-duration blast produced an M3-class solar flare and a CME that appears to be heading toward Earth. This movie from the Solar Dynamics Observatory shows the extreme UV flash:

NASA's twin STEREO spacecraft recorded an impressive CME emerging from the blast site: movie #1, movie #2. Analysts at the Goddard Space Weather Lab confirm that the CME is heading for Earth, and they say strong geomagnetic storms are possible (although not guaranteed) when the cloud arrives this weekend. Their animated forecast track predicts an impact on Jan. 21st at 22:30 UT (+/- 7 hrs).