A rare and intense geomagnetic storm is forecasted for September 16, potentially pushing the northern lights as far south as California, Missouri, and parts of Europe.
Triggered by a massive solar flare and a subsequent coronal mass ejection (CME), this storm could allow mid-latitude regions to witness the aurora borealis in places that rarely see it. The National Oceanic and Atmospheric Administration (NOAA) has issued a G3 geomagnetic storm alert, indicating that tonight’s storm could produce dazzling auroras far beyond their usual reach near the poles.
What Caused This Geomagnetic Storm?
This geomagnetic storm has two principal causes, both linked to the recent intense solar activity. The primary source is a large coronal mass ejection (CME), a burst of plasma and magnetic field launched from the Sun during an exceptionally powerful X-class solar flare that occurred on September 14, 2024. The X4.5 flare, one of the strongest recorded in the current solar cycle, sent the CME hurtling toward Earth at high speeds. When these charged particles collide with Earth's magnetosphere, they cause disturbances that can result in stunning auroras.
Alongside the CME, the storm is also influenced by a coronal hole in the Sun’s atmosphere. Coronal holes are regions where the Sun’s magnetic field opens up, allowing solar wind to escape more freely. These streams of solar wind, combined with the impact of the CME, have created the perfect conditions for a powerful geomagnetic event. The interaction of these two phenomena led NOAA’s Space Weather Prediction Center to issue the G3 storm watch, indicating that auroras could be seen much farther south than usual.
Aurora Viewing: What to Expect
If the forecast holds, skywatchers across mid-latitudes could be treated to a spectacular aurora display. While the northern lights are usually visible only in regions near the Arctic Circle, such as Alaska, Canada, and Scandinavia, this storm may extend the auroras down to much lower latitudes. For those in the United States, this means that states like Oregon, Missouri, and California could see the vibrant greens, pinks, and purples of the aurora borealis.
Across Europe, regions as far south as Germany and Poland may also catch a glimpse of the northern lights. Past geomagnetic storms of similar intensity have produced impressive aurora shows, even with less powerful storms reaching the mid-latitudes. Given the strength of this particular storm, NOAA expects widespread visibility of the auroras under favorable weather conditions.
Timing and Space Weather Unpredictability
Despite the excitement around the forecast, space weather remains inherently unpredictable. The precise timing of the CME’s arrival at Earth is uncertain, though predictions suggest it could occur between 0600 UTC and 1800 UTC on September 16. Space weather physicist Tamitha Skov cautioned that the CME could be delayed or deflected due to fast solar wind streams, which would affect the intensity and visibility of the aurora. “The big solar storm launched during the X4.5 flare is on its way to Earth. NOAA and NASA predictions indicate arrival anytime from 0600 UTC to 1800 UTC, likely on the late side,” Skov wrote on X (formerly Twitter).
Other space weather forecasters, such as Sara Housseal, have echoed this caution, reminding aurora hunters to keep an eye on updates. “We’ve reached the point where we could expect the CME to arrive at any time based on model outputs, but there is still no sign that an arrival is imminent,” Housseal noted. For aurora enthusiasts, this unpredictability is part of the thrill of space weather events, as there’s always a chance that the storm might either fizzle out or surpass expectations.
How to Maximize Your Chances of Seeing the Aurora
To improve your chances of witnessing the aurora, it’s important to find a location with dark, clear skies far from city lights. Light pollution can diminish the visibility of the aurora, so heading to rural areas or parks will offer the best chance of catching the lights. Checking real-time space weather forecasts and apps can also be incredibly helpful for tracking when and where the auroras are most likely to appear. Popular apps like “My Aurora Forecast & Alerts” and “Space Weather Live” provide real-time updates and predictions based on your location.
As the night approaches, keep a close eye on the sky and follow updates from NOAA and other space weather experts. With the potential for a geomagnetic storm of this magnitude, the northern lights could put on a rare and memorable show for those lucky enough to be in the right place at the right time.