US warns of solar storm that could bring northern lights and energy concerns

Periodically, the Sun spews massive explosions of particles into the solar system. Sometimes, when solar flares target directly Earth, particles may create spectacular auroras in the night sky in many parts of the planet. Then there are other occasions when a strike can damage satellites, distort GPS signals, and disrupt power grids.

A federal center on Wednesday issued a severe space weather storm warning after a sun-monitoring spacecraft observed a large solar flare emanating from a sunspot in the sun's northern hemisphere, accompanied by an explosion of particles known as a coronal mass ejection.

“The concerning thing here is that it was right at the center of the sun,” Sean Dahl, service coordinator at the Space Weather Prediction Center, part of the National Oceanic and Atmospheric Administration, said during a news conference Wednesday afternoon.

If the eruption was at the center of the sun, that means at least part of it was likely aimed directly at Earth. It seemed large enough to cause potential disturbances. The shower could also cause the northern and southern lights to appear on Thursday evening, reaching closer to the equator than usual.

It was the second such watch, the space weather equivalent of a hurricane watch, that the center has issued in the past 19 years.

The first, in May, put the United States on alert for a severe solar storm that appeared to be headed toward Earth. That solar storm reached the highest level of “extreme,” but early warning allowed electric utilities to prepare and helped prevent major power outages.

The charged particles generated by the latest event — protons, electrons and helium nuclei — are accelerating at more than 2.5 million miles per hour, and are expected to begin colliding with Earth's magnetic field Thursday morning Eastern time.

Mr Dahl said the storm would likely not be as severe as the one in May. “The difference is that in May, we had a series of coronal mass ejections, one faster than the other,” Dahl said. “It brought everything together and enhanced the impact.”

But a geomagnetic storm can last about 36 hours. If the storm reaches severe level, the aurora borealis in the Northern Hemisphere could extend into the central United States, and possibly… South to Alabama.

The forecast will remain largely speculative until the particle waves pass by two spacecraft, NASA's Advanced Composition Explorer, or ACE, and the Deep Space Climate Observatory, or DSCOVR.

Both are about a million miles from Earth, providing 15 to 30 minutes of warning before solar storms reach Earth. At this point, the watch may be upgraded to warning level.

In May, the center began talking with power grid operators about six hours before the storm arrived.

And this time, they're reaching out early, because the power grid, already damaged by Hurricane Helen last month, will take more hits as Hurricane Milton approaches Florida.

“As hurricane relief efforts continue and the hurricane reaches Florida and across the peninsula, we thought it would be prudent to contact them immediately now,” Mr. Dahl said. “We don't know the real situation there, but that's what worries us.”

Neither May's eruption nor this week's explosion is as serious as the event known as the Carrington event that struck Earth in 1859, knocking out telegraph stations, or another event in 1989 that caused a nine-hour blackout in Quebec.