WASHINGTON (AP) — A solar storm shook the Earth's magnetic field early Friday, but scientists said they had no reports of any problems with electrical systems.
After reports Thursday of the storm fizzling out, a surge of activity prompted space weather forecasters to issue alerts about changes in the magnetic field.
"We really haven't had any reports from power system operators yet," Rob Steenburgh, a space weather forecaster at the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Boulder, Colo., said early Friday. "But sometimes they don't come in until after the storm."
He said the storm reached a moderate level late Thursday, before going to a strong level early Friday. For most of Thursday, it was rated as minor.
Scientists say such storms don't pose a threat to people, just technology.
The space weather center's website says a storm rated as strong could force corrections to voltage systems and trigger false alarms on some protection devices, as well as increase drag on satellites and affect their orientation.
The forecasters weren't aware of any significant impact to electrical or technological systems, but said there was a two-hour blackout of high frequency radio communications — affecting mainly ham radio operations — stretching from eastern Africa to eastern Australia.
Steenburgh also said that there was another solar flare late Thursday, similar to the one a few days ago that set off the current storm.
"Right now we're still analyzing when it will arrive" and how strong it could be, he said.
The space weather center had reports of Northern Lights across Canada and dipping into the northern tier of U.S. states, Steenburgh said.
While some experts thought the threat from the solar storm passed by earlier Thursday, the space weather center maintained the storm's effects could continue through Friday morning.
The current storm, which started with a solar flare Tuesday evening, caused a stir Wednesday because forecasts were for a strong storm with the potential to knock electrical grids offline, mess with GPS and harm satellites. It even forced airlines to reroute a few flights on Thursday.
It was never seen as a threat to people, just technology, and teased skywatchers with the prospect of colorful Northern Lights dipping further south.
But when the storm finally arrived around 6 a.m. EST Thursday, after traveling at 2.7 million mph, it was more a magnetic breeze than a gale. The power stayed on. So did GPS and satellites. And the promise of auroras seemed to be more of a mirage.
Scientists initially figured the storm would be the worst since 2006, but now seems only as bad as ones a few months ago, said Joe Kunches, a scientist at the NOAA center. The strongest storm in recorded history was probably in 1859, he said.
"It's not a terribly strong event. It's a very interesting event," Kunches said.
Forecasters can predict the speed a solar storm travels and its strength, but the north-south orientation is the wild card. This time it was a northern orientation, which is "pretty benign," Kunches said. Southern would have caused the most damaging technological disruption and biggest auroras.
On Thursday, North American utilities didn't report any problems, said Kimberly Mielcarek, spokeswoman for the North American Electric Reliability Corporation, a consortium of electricity grid operators. Her office didn't respond to a phone call early Friday.