What is a G5 geomagnetic storm?

USA TODAY - For more and to sign up click here Russell Falcon (NEXSTAR) — On Friday night, the most significant G5 geomagnetic storm since 2003 hit Earth — causing several coronal mass ejections, or CMEs — and allowing many across the U.S. to see northern lights where they usually can’t. But just what does all this mean? To start with, as explained by the weather team at Nexstar’s WGN-TV in Chicago, a geomagnetic…