NOAA’s Space Weather Prediction Center
WASHINGTON — A severe solar storm smacked Earth with a surprisingly big geomagnetic jolt Tuesday, potentially affecting power grids and GPS tracking while pushing the colorful northern lights farther south, federal forecasters said.
No damage had been reported as of Tuesday afternoon. Two blasts of magnetic plasma left the sun Sunday, combined and arrived on Earth about 15 hours earlier than expected — and much stronger — said Thomas Berger, director of the Space Weather Prediction Center in Boulder, Colo.
This storm ranks a 4 on the National Oceanic and Atmospheric Administration’s 1-to-5 scale for geomagnetic effects. It is the strongest solar storm since fall 2013. It’s been nearly a decade since a level 5 storm hit Earth.
Forecasters figured it would come as a level 1 late Tuesday night or Wednesday morning; instead, it arrived just before 7 a.m. Pacific Time on Tuesday.
Forecasters had predicted a glancing blow instead of a dead-on hit, Berger said. Another theory is that the combination of the two storms may have made it worse, he said.
The storm seemed to be weakening slightly, but could last all day, officials said. It has the potential to disrupt power grids but only temporarily. It also could degrade the global positioning system, making tracking maps and locators less precise.
Such storms often bring radiation bursts that affect satellite operation, but this one has not, Berger said.
But the most noticeable effect is usually considered a positive. The Aurora Borealis or northern lights, which usually can be viewed only in the far north, dipped south, so more people could enjoy the colorful sky show.
Forecasters said before sunrise Tuesday, auroras were seen in the northern tier of the U.S. — Washington, North Dakota, South Dakota, Minnesota and Wisconsin.
Space Weather branch chief Brent Gordon said if the storm’s effects continued through Tuesday evening, there was a “very strong possibility” that the northern lights could be seen as far south as Tennessee and Oklahoma. That also means much of Russia and northern Europe, as far south as central Germany and Poland, had the potential for the sky show if skies were clear.
