Update 4pm, Nov 6th on AR 2781. Copy of report on SpaceWeather.com.
So far, the strongest solar flare from AR2781 has been a C7-class explosion at 0022 UT on Nov. 5th. X-rays and UV radiation from the flare ionized the top of Earth's atmosphere, causing a brief low-frequency radio blackout over the Pacific Ocean and Australia.
Mariners and ham radio operators in the region might have noticed signals fading, especially at frequencies below 10 MHz.
More C-class flares are almost guaranteed in the hours ahead, with a slight change of even stronger M-class flares.