Extreme geomagnetic storm
on sun

Causing possible power outages and satellite disruption, an extreme geomagnetic storm occurred yesterday that registered at the highest level on measurements of such solar activity.

Extreme geomagnetic event recorded on sun on Sunday (NOAA photo)

Forecasters at the National Oceanic and Atmospheric Association Space Environment Center in Boulder, Colo., observed the event, which measured G-5 – the highest level – on the NOAA Space Weather Scales.

"This event registered a 9 on the K-Index, which measures the maximum deviation of the Earth's magnetic field in a given three-hour period," Gayle Nelson, lead operations specialist at NOAA Space Environment Center, said in a statement. "The scale ranges from 0 to 9, with 9 being the highest. This was a significant event."

The event was forecast by NOAA as the result of a solar flare that occurred on Friday, May 13.

Possible impacts from such a geomagnetic storm include widespread power system voltage control problems with some grid systems may experience complete collapse or blackouts. Transformers may experience damage. Spacecraft operations may experience extensive surface charging, including problems with orientation, and uplink/downlink and tracking satellites. Satellite navigation may be degraded for days, and low-frequency radio navigation can be out for hours. Reports received by the NOAA Space Environment Center indicate that such impacts have been observed in the U.S., the agency says.

"We usually have something of this magnitude only about four or six times a year, so this is kind of a big event," Mowry said Florida meteorologist Larry Mowry.