Magnetic Storm Bound For Earth

A strong geomagnetic storm was expected to hit Earth on Friday with the potential to affect electrical grids and satellite communications.

One of the largest sunspot clusters in years developed over the past three days and produced a coronal mass ejection, similar to a solar flare, at 3 a.m. EDT Wednesday, forecasters at the National Oceanic and Atmospheric Administration said.

The disturbance was expected to produce a geomagnetic storm rated G3. A G5 storm is the strongest.

The storm could make the aurora visible as far south as Oregon and Illinois.

A coronal mass ejection is an explosion of gas and charged particles into space from the corona, the outermost layer of the sun's atmosphere.

A second sunspot cluster not yet visible from Earth could produce more geomagnetic storms in the next two weeks, NOAA said.