CAPE CANAVERAL, Fla. (AP) — An unusually strong solar storm headed toward Earth could produce northern lights in the U.S. this weekend and potentially disrupt power and communications.
The National Oceanic and Atmospheric Administration issued a rare geomagnetic storm watch — the first in nearly 20 years. That was expected to become a warning Friday night, when the effects of the solar outburst were due to reach Earth.
NOAA already has alerted operators of power plants and spacecraft in orbit to take precautions.
“As far as the worst situation expected here at Earth, that’s tough to say and I wouldn’t want to speculate on that,” said NOAA space weather forecaster Shawn Dahl. “However, severe level is pretty extraordinary, It’s a very rare event to happen.”
NOAA said the sun produced strong solar flares beginning Wednesday, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth. Each eruption — known as a coronal mass ejection — can contain billions of tons of plasma and magnetic field from the sun's outer atmosphere, or corona.
The flares seem to be associated with a sunspot that’s 16 times the diameter of Earth, according to NOAA. An extreme geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa.
The latest storm could produce northern lights as far south in the U.S. as Alabama and Northern California, according to NOAA.
The most intense solar storm in recorded history, in 1859, prompted auroras in central America and possibly even Hawaii. “That's an extreme-level event," Dahl said. “We are not anticipating that” but it could come close.
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WASHINGTON —NOAA’s Space Weather Prediction Center (SWPC) — a division of the National Weather Service — is monitoring the sun following a series of solar flares and coronal mass ejections (CMEs) that began on May 8. Space weather forecasters have issued a Severe (G4) Geomagnetic Storm Watch for the evening of Friday, May 10, according to a statement from the space weather prediction center. Additional solar eruptions could cause geomagnetic storm conditions to persist through the weekend.
A large sunspot cluster has produced several moderate to strong solar flares since Wednesday at 5:00 am ET. At least five flares were associated with CMEs that appear to be Earth-directed. SWPC forecasters will monitor NOAA and NASA’s space assets for the onset of a geomagnetic storm.
CMEs are explosions of plasma and magnetic fields from the sun’s corona. They cause geomagnetic storms when they are directed at Earth. Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting phone communications, the electric power grid, navigation, radio and satellite operations.
SWPC has notified the operators of these systems so they can take protective action. Geomagnetic storms can also trigger spectacular displays of aurora on Earth. A severe geomagnetic storm includes the potential for aurora to be seen as far south as Alabama and Northern California.