A NOAA model shows how far south the geomagnetic storm could create auroras.

(NOAA Space Weather)

Space forecasters say a large geomagnetic storm hit Earth sooner — and with more force — than they projected Tuesday morning. And it could have impacts into the Southern U.S. overnight.

According to NOAA, the storm is courtesy of (CME) that left the sun Sunday, March 15 and reached Earth at 10 a.m. ET Tuesday. It ranked a class 4, which is considered severe on NOAA's scale from 1-5, making it the strongest to hit since fall 2013.

"It's significantly stronger than expected," Thomas Berger, director of the Space Weather Prediction Center in Boulder, Colorado, told The Associated Press. Forecasters had predicted a glancing blow instead of dead-on hit. Another theory is that the combination of the two storms made it worse, but it's too early to tell if that's so, he said.

Geomagnetic storms can often threaten GPS and power grids, but no damage or outages have been reported so far.

The most noticeable impact has been the extraordinary display of northern lights reaching further south than usual. People from Wisconsin, Minneapolis, Washington state and even the Dakotas reported seeing the bright lights before sunrise Tuesday.

Astronaut Terry Virts also tweeted a stunning view from the International Space Station.

Space Weather branch chief Brent Gordon said if the storm effects continued through Tuesday evening, there was a "very strong possibility" that the northern lights could be seen as far south as the middle United States, even 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.

As for weather on earth, weather.com meteorologist Linda Lam says we’ll have clear skies from the Midwest into parts of the MidAtlantic overnight, while the chance of clouds increases from the Southern Plains into the Northern Tier and West after midnight.

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