LI's Dazzling Northern Lights Due To Rare Geomagnetic Storm: Photos

LONG ISLAND, NY — A rare geomagnetic storm Thursday led to a dazzling display of aurora borealis, or Northern lights, in the night sky — stirring up excitement among those who savored what they said was a once-in-a-lifetime experience.

Here's why it happened: Space weather forecasters have issued a severe, G4-level geomagnetic storm watch, only the second of that severity in 20 years, after a strong X-class solar flare and coronal mass ejection that was set to push the aurora borealis from the northern states as far south as Alabama Thursday and Friday.

No matter what the explanation, Long Islanders were in awe: "I can't believe it," Albie de Kerillis told Patch. "I have never witnessed anything like this in my lifetime."

Forecasters with the Space Weather Prediction Center, a division of the National Oceanic and Atmospheric Administration, said in a news briefing Wednesday that the CME, carried to Earth by fast-moving solar winds, was due to arrive Thursday morning or midday Eastern time. The CME arrived as predicted

The storm watch alert says the aurora might become visible over much of the northern half of the country, and maybe as far as Alabama and northern California.

Geomagnetic storm alerts are rare. In May, NOAA issued a similar statement about the strong solar storm that produced the strongest aurora display in perhaps hundreds of years. The aurora was visible widely in the United States, including in places near the southern border, and around the world.

The geomagnetic storm is ranked a G4 on a scale of 1-5, and the Kp Index, the measure of auroral strength, is 8 on a scale that tops at 9. A Kp index of 5 is generally required for the aurora borealis to be visible.

The X1 flare that produced it isn’t nearly as strong as the X8.7 flare in May that made the aurora visible in areas along the southern U.S. border, or the more recent even stronger X9 flare that produced northern displays in about a third of the country this week.

“Lady Aurora,” as some people have begun to call the shimmering curtains of pink, red, green and yellow, is fickle. Strong solar flares and high Kp indexes don’t always translate to light displays.

Mike Bettwy, the head of the SWPC’s forecast office, said aurora chasers are usually rewarded within a couple of hours after nightfall. Patience is a key, he said.

“The key is the magnetic orientation,” he said. “It’s remarkable how quickly the aurora can shut down and diminish, and just as quickly return.”

If you have photos to share, email Lisa.Finn@patch.com.

With reporting by Beth Dalbey.