The Chicago area may have another chance of seeing the dazzling Northern Lights light up the sky Friday, Oct. 11. But that's only if cloudy conditions remain at bay.
"Hopefully we can keep some of these clouds at bay after sunset," NBC 5 Meteorologist Pete Sack said, as clouds were in the Chicago forecast Friday afternoon and into evening.
According to the Space Weather Prediction Center and the National Oceanic and Atmosphere Administration, a "severe" geomagnetic storm watch is once again in effect for Friday. That same watch was in effect for Thursday, leading to the aurora being seen much further south than usual.
"Watches at this level are very rare," the agency said.
The Northern Lights are enhanced when coronal mass ejections, or CME’s, erupt from the sun and speed across space before hitting Earth’s atmosphere. According to the SWPC, CME’s are “large explosions of plasma and magnetized particles from the Sun’s corona.”
Those ejections expand in size as they approach Earth’s atmosphere, and can cause geomagnetic storms when they arrive.
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According to the SWPC, auroras can be observed just after sunset or before sunrise. They are not visible during daytime hours, and do not need to be directly overhead to be seen, if conditions are bright enough.
"For many people, the aurora is a beautiful nighttime phenomenon that is worth traveling to arctic regions just to observe," the SWPC said. "It is the only way for most people to actually experience space weather."
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Luckily, much of the northern half of the U.S. didn't have to go far to see them Thursday, and might have the same chance of seeing them Friday.
The SWPC reports the aurora Friday is expected to visible "over much of the northern half of the country," and potentially as far south as Alabama.
According to the Space Weather Prediction Center's latest viewing forecast for Friday, the "viewline" -- the southern-most locations from which people may see the aurora on the northern horizon -- includes portions of Northern and Central Illinois.
Though the lights may be visible with the naked eye, pictures taken with digital cameras may make auroras more visible.
If you didn't get a chance to look up Thursday, or you'll be unable to step outside Friday evening, here's a look back at the aurora visible across the Chicago area last night.