GEOMAGNETIC STORM WATCH (G3): A series of three CMEs is now heading for Earth. The first two, launched by M-class flares on August 7th, are relatively minor. The third, launched by yesterday's #X-flare (described below), is more potent. Striking Earth in succession on Aug. 9th, 10th, and 11th, the three CMEs could spark geomagnetic storms as strong as category G3 with mid-latitude auroras in the USA and Europe. CME Impact alerts: SMS Text
X-CLASS SOLAR FLARE AND HALO CME: Active sunspot AR3777 just produced its most powerful solar flare yet--an X1.3-class explosion on Aug. 8th (1935 UT). NASA's Solar Dynamics Observatory recorded the extreme ultraviolet flash:
Radiation from the flare ionized the top of Earth's atmosphere and caused a shortwave radio blackout from North America to the Hawaiian islands. Mariners and ham radio operators may have noticed loss of signal below 30 MHz for as much as an hour after the flare.
Of greater interest is the coronal mass ejection (CME). Soon after the flare, SOHO coronagraphs detected a halo #CME heading straight for #Earth: