Northern lights may be visible unusually far south tonight. Here’s where.
Northern lights may be visible in swaths of the United States on Monday night, including in places unusually far south, after a powerful X-class solar flare ejected from the sun late this weekend.
A key NASA model shows the magnetic shock wave called a coronal mass ejection, or CME, may be stronger and faster than originally modeled. It could slam Earth’s magnetic field around 8 p.m. Eastern time Monday night, its impact potentially sparking a wave of auroral displays.
A storm of this strength could allow aurora to be visible to the naked eye at least as far south as parts of California, the central Plains and the Mid-Atlantic. There is potential for lights even to the south of those locations.
Long-exposure - including cellphone - photos would also be able to capture such an event at more southerly latitudes. Places such as Southern California, Texas and the Deep South would be included, with some potential for the lights to dip into Mexico or beyond.
In response to the latest outburst from the sun, NOAA’s Space Weather Prediction Center issued its highest alert for geomagnetic storm potential. It calls for a severe storm, or a G4 out of a maximum of 5.
“Watches at this level are very rare,” the center wrote.
There are inherent uncertainties to the show - namely whether the bulk of the CME hits Earth head-on or only grazes the planet. The latter scenario is a distinct possibility.
The solar flare
This is all associated with an X2-class solar flare, which launched off the sun around 11:09 a.m. Eastern time Sunday. It originated from sunspot 4,341, a large, bruise-like discoloration on the surface of the sun throbbing and pulsating with magnetic energy.
In addition to their enhanced magnetism, sunspots are unstable and cooler regions on the sun’s surface.
Solar flares are flashes of light and electromagnetic radiation that expel high-energy particles through space at the speed of light. This particular flare caused a degradation of radio wave propagation and partial radio blackout over western South America and the eastern South Pacific.
It comes as the sun continues to be near its solar maximum, an 11-year cycle on average. Sunspots are at their greatest concentration during these maximums. They are a primary cause of CMEs and solar flares.
The last significant outbreak of aurora occurred in November.
The geomagnetic storm
The solar flare was followed by a CME. CMEs are slower waves of magnetism and ejected solar plasma that surf through space like a shock wave. They typically take one to three days to reach Earth, if pointed in our direction. As it’s expected to reach us in about 36 hours, this would be a very speedy CME.
Stronger CMEs are usually faster than weaker ones.
In this case, the CME was approaching Earth as of midafternoon Monday. The timing may be ideal for much of North America and Europe - at least in some places, skies may illuminate in the hours after sunset.
CMEs interact with Earth’s magnetic field, transforming potentially harmful energy and magnetism into visible light - the aurora. Colors of the aurora are caused by the energy interacting with oxygen and nitrogen among others at high levels of the atmosphere.
How to view
To maximize visibility, get away from city lights and find a clear, unobstructed view of the northern horizon. Check the weather forecast first, too.
With much of the Lower 48 currently free of major weather systems, clear or partially cloudy skies should dominate much of the land. Areas that may experience the most clouds are generally near the Mexico border and into Texas plus parts of the South. Cloudiness may also favor the border with Canada, especially near the northern Rockies and Great Lakes.
Your best bet will be to look northward a couple times per hour after dark through at least midnight.
Social media and space weather related websites often deliver a critical heads-up.