Emerging sunspot AR3869 erupted this morning (Oct. 24th @ 0357 UTC), producing a slow X3.3-class solar flare.
Extreme ultraviolet radiation from the flare ionized the top of Earth’s atmosphere. This, in turn, caused a shortwave radio blackout over Australia and Southeast Asia. Ham radio operators may have noticed loss of signal at frequencies below 30 MHz for as much as an hour after the flare.
Of greater interest is the coronal mass ejection. The explosion launched a bright CME into space. The bulk of this CME will miss Earth, but there is an Earth-directed component. According to a NASA model, the CME’s flank will strike our planet on Oct 26th (around 0600 UTC). The glancing blow could cause a minor G1-class geomagnetic storm.