Tuesday night a G4 geomagnetic storm driven by X-class solar flares and multiple CMEs produced vivid Northern Lights across northeast Wisconsin. SWPC reported one early-morning CME's magnetic field was about eight times stronger than normal, and a third CME was expected around midday Wednesday. SWPC Coordinator Shawn Dahl said a G5 is a slight-to-real possibility; visibility will depend on the next CME's strength and local weather. Skywatchers were urged to keep an eye on the skies for another possible display.
Northern Lights Ignite Wisconsin Skies During Powerful G4 Geomagnetic Storm — G5 Possible
Tuesday night a G4 geomagnetic storm driven by X-class solar flares and multiple CMEs produced vivid Northern Lights across northeast Wisconsin. SWPC reported one early-morning CME's magnetic field was about eight times stronger than normal, and a third CME was expected around midday Wednesday. SWPC Coordinator Shawn Dahl said a G5 is a slight-to-real possibility; visibility will depend on the next CME's strength and local weather. Skywatchers were urged to keep an eye on the skies for another possible display.
01:25 AM, 11/13/2025Science
Northern Lights Ignite Wisconsin Skies During Powerful G4 Geomagnetic Storm
Tuesday night produced dramatic displays across northeast Wisconsin as the Northern Lights shimmered during a G4-strength geomagnetic storm. The event followed a period of elevated solar activity that included X-class flares and multiple coronal mass ejections (CMEs) — clouds of plasma and magnetic field blown off the Sun.
Photographers and residents shared striking images from locations across the state, capturing vivid bands of green, red and purple that reached well beyond typical viewing zones.
According to the Space Weather Prediction Center (SWPC), the magnetic field associated with one of two CMEs that moved past Earth early Wednesday measured about eight times stronger than normal, SWPC Service Coordinator Shawn Dahl said in a 4 a.m. ET update.
'The chances for a G5 do exist,' Dahl said. 'We’re calling it a slight chance to a chance at this time. But since we’re still expecting that third coronal mass ejection arrival, that’s going to cause us to have some escalated conditions yet again, perhaps.'
SWPC also reported a third CME was expected to arrive around midday Wednesday, which could spark additional geomagnetic activity and produce another round of visible auroras if the timing and strength align. Local weather and cloud cover will determine whether observers actually see the lights.
G4 storms can push auroras as far south as Alabama and California; if conditions intensify to a G5, the lights could reach into Florida and Texas. Although forecasts before Tuesday suggested more limited visibility, the aurora extended beyond expected ranges — prompting skywatchers across the U.S. to keep watching the skies.
Shelter-in-place restrictions near Door County’s Cherryland Airport were lifted after the overnight events.
Note: Strong geomagnetic storms can sometimes affect satellites, radio communications, and electrical systems. For real-time updates and guidance, consult the SWPC and local authorities.