NOAA forecasters estimate a 45% chance of polar geomagnetic storms on July 29-30 in response to a high-speed solar wind stream buffeting Earth’s magnetic field. Even stronger storming could occur on July 31st when a CME associated with yesterday’s M6-flare arrives. High-latitude sky watchers should be alert for auroras for the next three nights.
Sunspot AR1532 is crackling with M-class solar flares. The latest, an M6-class eruption on July 28th (2056 UT), produced a bright flash of extreme ultraviolet radiation, shown here in a snapshot from the Solar Dynamics Observatory:
Contrary to earlier reports, this explosion did produce a CME and the cloud is heading for Earth. According to a forecast track prepared by analysts at the Goddard Space Weather Lab, the CME will reach our planet on July 31st at 1500 UT (+/- 7 hours). Weak to moderate geomagnetic storms are possible when the cloud arrives.