SOLSTICE GEOMAGNETIC STORM: A series of CMEs hit Earth’s magnetic field on June 22nd, producing a severe G4-class geomagnetic storm. Northern Lights spilled across the Canadian border into more than a dozen US states, including places as far south as Colorado, Georgia, Virginia and Arkansas. “The auroras did not disappoint,” says Chris Cook, who witnessed the display from Cape Cod, Massachusetts:
“They were visible in deep twilight!” he adds. “I positioned myself on a beach overlooking Cape Cod Bay so I could capture the reflection in the water at low tide.”
More auroras are in the offing as Earth’s magnetic field reverberates from the CME strikes. NOAA forecasters estimate a 90% chance of polar geomagnetic storms on June 23rd, subsiding only a little to 70% on June 24th. Aurora alerts: text, voice
Realtime Aurora Photo Gallery
X-ray and UV radiation from the flare ionized the upper layers of Earth’s atmosphere, causing a blackout of some shortwave radio signals over North America (blackout map). Mariners and ham radio operators, in particular, may have noticed disturbances at frequencies below ~20 MHz.
The explosion also hurled a full-halo CME directly toward Earth: movie. NOAA analysts are still modeling the storm cloud to estimate its likely time of arrival. Best guess: June 24th.