Sunspot group, AR11520, produced an X1.4 solar flare, peaking in the NOAA GOES X-ray monitor at 16:52 UT (12:52 EDT). This flash of electromagnetic radiation temporarily altered the upper atmosphere changing its ability to reflect and transmit certain radio frequencies. This produced a radio blackout lasting around 1 hour. This radio blackout event is an R3 event on the NOAA scale (R1-R5 scale). Along with the flare high energy subatomic particles at the S1 level (S1-S5 scale).
There was an associated coronal mass ejection (CME) launched in the direction of Earth.
Here is the computer model from NASA Goddard Space Weather Center. The CME is predicted to impact Earth, Messenger, Spitzer, MSL, Mars. The CME is expected to impact Earth 7/14/2012 at 10:20 UT (+-7 hrs), 6:20 am EDT.
The predicted impact is for a G2 – G4 level geomagnetic storm, moderate to severe. This could produce aurora as far south as northern California and Alabama. This would be into central UK and Europe or southern New Zealand. At its worst it could lead to some intermittent satellite/radio navigation problems, surface charging on satellites and power grid fluctuations. But the larger storm is less likely as these are rough estimates.
credit: NASA Goddard Space Weather Center
original alert: http://swc.gsfc.nasa.gov/main/20120712-AL-006