Solar Flares and Radio Blackouts

Solar Flares and Radio Blackouts

Departing sunspot AR2290 is crackling with M-class solar flares. The strongest so far, an M8-class explosion on March 3rd @ 01:35 UT, almost crossed the threshold into X-territory. NASA's Solar Dynamics Observatory recorded the extreme ultraviolet flash:
A pulse of radiation from the flare ionized the upper layers of Earth's atmosphere. This caused a blackout of radio transmissions at frequencies below 10 MHz. The effect was particularly strong above Australia and parts of the south Pacific: blackout map.
NOAA forecasters estimate a 25% chance of more M-class flares on March 3rd, subsiding to 10% on March 4th as sunspot AR2290 rotates onto the farside of the sun. Ham radio operators and mariners may notice disturbances to HF communicatons during the next 24-48 hours.

From SpaceWeather.com