A powerful geomagnetic storm hit Earth on Friday, the strongest in over 20 years, causing radio blackouts and extending the display of the northern lights to the southern U.S. As the week began, officials warned that the storm was ongoing, with the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center issuing a G3, or “strong,” geomagnetic storm warning. Although conditions were expected to gradually improve throughout the day, moderate to strong geomagnetic storms were still likely for Monday, with minor storms anticipated for Tuesday.
In addition to the ongoing geomagnetic storm, high levels of solar activity were expected, with the possibility of more solar flares. The update coincided with the recording of another X-class solar flare, the strongest classification of such events, which was labeled as “moderate.”
According to the Space Weather Prediction Center, flares of this magnitude are uncommon and may result in temporary disruptions or complete loss of HF radio signals on the sunlit side of Earth. Another X-class flare on Sunday likely contributed to hour-long high-frequency radio blackouts across wide areas of the Earth’s sunlit side.
These flares originated from Sunspot Region 3664, a significant area of the sun responsible for the weekend’s extreme geomagnetic storm. The region remains active and complex, leading to ongoing CMEs and flares. Solar radiation storms and further radio blackouts are expected to persist throughout the week due to continued CME influences.
The complexity and size of Sunspot Regions 3664 and 3663 are noteworthy, with the former being visible to the naked eye from Earth due to its massive size. NOAA emphasized the magnetically complex nature of these regions and their substantial impact on solar activity.
As the week progresses, the forecast anticipates a decrease in geomagnetic responses but warns of potential unsettled to G1 (Minor) levels of activity. Solar radiation storms are also expected, along with the possibility of strong radio blackout events, depending on the intensity of solar flares.