Waiting for the CME.
A CME expected to sideswipe Earth’s magnetic field on July 23rd did not arrive on time. It might have missed, or it may yet deliver a glancing blow later today. There is a slight chance of G1-class geomagnetic storms in response to a tardy arrival on July 24th.
Long duration solar flare.
Today began with an explosion on the sun. Minutes after UT midnight, sunspot AR2849 erupted, producing a long-duration C4-class flare. NASA’s Solar Dynamics Observatory recorded the ultraviolet flash:An hour-long pulse of X-rays and ultraviolet radiation ionized the top of Earth’s atmosphere, disrupting the usual propagation of radio waves over the Pacific Ocean. Mariners, aviators, and ham radio operators may have noticed sudden drops in signal strength at frequencies below 20 MHz.
Mike Terry to WOR iog (2021-07-24)