The experimental Magnetometer, which measures Earth’s magnetic field strength, has detected a significant change just before 16:00.  This is the first event detected/recorded since data collection started in November 2012.

… same data zoomed out:

And to verify the event, here’s a graph from the GOES-13 and GOES-15 satellites:

The following alert message was issued by NOAA: http://www.swpc.noaa.gov/alerts/alerts_timeline.html :

“Space Weather Message Code: ALTEF3
Serial Number: 1984
Issue Time: 2013 Jan 17 1343 UTC
ALERT: Electron 2MeV Integral Flux exceeded 1000pfu
Threshold Reached: 2013 Jan 17 1315 UTC
Station: GOES13
Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems.”