Just when you thought the sun might be taking a breather, another powerful eruption was unleashed, and the northern lights forecast became even more promising. A fourth coronal mass ejection (CME) erupted from the sun on October 8, during a powerful M-class solar flare from the restless sunspot region AR4549. This brings the number of CMEs potentially headed toward Earth to four, raising the possibility of increased geomagnetic activity and auroral viewing in the coming days. Early analyzes suggest that the last CME could potentially catch up with the third CME on its way to Earth. Will the Northern Lights be visible in the United States? NOAA’s aurora forecast suggests that auroral activity could increase across northern North America. Exactly how far south the aurora could appear remains uncertain and depends on how the incoming CMEs interact with Earth’s magnetic field. G2 geomagnetic storm conditions are forecast for October 9, and during such storms, auroras have previously been observed as far south as New York and Idaho. You May Like While the northern US states currently have the best prospects, skywatchers further south shouldn’t completely rule out their chances just yet. With multiple CMEs approaching Earth in rapid succession, there is still considerable uncertainty about how geomagnetic conditions will develop. If the incoming flares interact favorably with Earth’s magnetic field, auroras could reach much further south than currently predicted. Aurorals are possible in the northern US tonight (after midnight UTC). (Image credit: Map inset: NOAA Space Weather Prediction Center, background added in Canva Pro.) So if you’re in mid-latitudes, make sure your aurora alerts are on and your camera batteries charged. These could be an interesting few days for Northern Lights enthusiasts! To get real-time forecasts based on your location, consider using a space weather app. A great option is “My Aurora Forecast & Alerts” (available for iOS and Android). For a deeper dive into space weather conditions, “Space Weather Live” is another great option (available for iOS and Android). Aurora forecast for the Northern Hemisphere, courtesy of the UK Met Office. When should you look for the Northern Lights? NOAA’s latest 3-day forecast now places the strongest geomagnetic activity later than previously expected on October 9. Minor geomagnetic storm conditions (G1) are forecast between 8 am and 2 pm EDT (1200 and 1800 GMT), with moderate conditions (G2) expected between 2 and 8 pm EDT (1800 and midnight GMT). What to read next More activity is possible over the weekend, with NOAA currently forecasting minor (G1) conditions between 11 pm and 2 am EDT on October 10-11 (0300-0600 GMT October 11). For those who want to capture some auroras, the advice remains the same! Keep your aurora alerts on and check conditions whenever the sky is dark and clear. These forecast windows are not set in stone, particularly when multiple CMEs are involved! When could CMEs arrive? Model showing expected arrival times for incoming CMEs. (Image credit: NOAA Space Weather Prediction Center) This is where things get complicated. Current models suggest that the first CMEs could reach Earth on October 9. Space weather physicist Tamitha Skov notes that the two CMEs on October 6 could reach Earth in relatively quick succession, dealing a double blow to Earth’s magnetic field. However, its journey can be influenced by the surrounding solar wind, making it difficult to nail down precise arrival times. The third CME could follow late October 10 or early October 11 (UTC), potentially prolonging unstable geomagnetic activity and aurora prospects into the weekend. And now there is a fourth CME to consider. Early analyzes suggest that this latest eruption is traveling faster than some of its predecessors, raising the possibility that it could overtake the third CME before reaching Earth. The ‘cannibal CME’ could further complicate the timing and strength of the resulting geomagnetic activity. And remember, even a CME aimed at Earth doesn’t guarantee a spectacular auroral display. Much will depend on how the magnetic fields carried by these eruptions interact with Earth’s magnetic field when they arrive. With AR4549 still magnetically complex and facing Earth, more solar activity could be on the way. The sun is sure to keep us on our toes this week! Editor’s note: This article has been updated to include a fourth coronal mass ejection (CME) that emerged from the sun on October 8, along with the latest geomagnetic storm forecasts and revised arrival estimates.
