On Tuesday, November 11, 2025 Region 4274 released an X5.1 flare (R3-Strong) at 11/1004 UTC. This event is considered to be one of the strongest flares of the solar cycle. A G4 severe geomagnetic storm is predicted for November 12. Further information about this event is provided by the Space Weather Prediction Center bulletin listed below.
Image/NOAA
Space Weather Prediction Center
National Oceanic and Atmospheric Administration Bulletin
G4 (Severe) Watch in Effect for 12 November
published: Tuesday, November 11, 2025 17:21 UTC
Geomagnetic Storm Watches in Effect, to include G4 (Severe) potential for 12 November. The current list of Watches include: 11 Nov G2 (Moderate); 12 Nov G4 (Severe); and 13 Nov G3 (Strong). These Watches are in response to potential geomagnetic storm effects related to coronal mass ejections (CME) that have erupted from the Sun over the past several days. These events include CME activity from 9 November through the early morning of 12 November. The most recent CME occurred early on 12 Nov and is the most energetic and fastest of the CMEs. This CME was associated with an X5.1 solar flare (R3; Strong) that peaked at 1004 UTC (5:04 am EST) on 11 Nov. This CME is also associated with a moderate level solar radiation storm (S2) that is currently in progress. The forecast is tough due to this latest CME’s predominant ejecta aimed north and ahead of Earth’s orbit; additionally the previous CMEs are in the mix and anticipated to have some Earth-arrival influences prior to the 12 Nov CME arrival. Confidence in an Earth-component to the most recent CME is high, while timing has a moderate level of certainty. As always with these events, the intensity of the CME will not be know with better certainty until it arrives 1 million miles from Earth and is observed by the solar wind observatories at that location. It is at that point that any needed Warning decisions can be made by SWPC forecasters. So, for now, SWPC believes there is a potential for G4 levels upon CME arrival and/or as the CME passage progresses. Stay space weather aware and follow the latest information, forecasts, and updates at spaceweather.gov
