A coronal mass ejection (CME) produced by the August 30, 2025, long-duration M2.7 solar flare impacted Earth at 21:01 UTC on September 1, producing G1 – Minor to G2 – Moderate geomagnetic storm conditions.
A coronal mass ejection (CME) associated with the long-duration M2.7 solar flare on August 30 impacted Earth’s magnetosphere at 21:01 UTC on September 1. The impact caused an abrupt increase in solar wind speed to between 600 and 675 km/s and raised the total interplanetary magnetic field (Bt) to 20–26 nT.
The initial response included a G1 – Minor geomagnetic storm onset at 21:08 UTC, followed by G2 – Moderate geomagnetic storming at 22:41 UTC, according to NOAA’s Space Weather Prediction Center (SWPC).
Despite unfavorable magnetic orientation in the CME’s structure, which limited equatorward auroral penetration, auroras were still reported in mid-latitudes. Purple auroral pillars were seen as far south as Barker, New York, according to space weather physicist Dr. Tamitha Skov.
“Although the poor magnetic orientation of this solar storm has kept most aurora shows at higher latitudes, there have been some nice substorm brightenings,” she said.
WOW pic.twitter.com/xuVWWbjLWF
— James Pettus (@PettusWX) September 2, 2025
The northern lights are out in Grand Bend, Ontario. #Aurora #Auroraborealis #northernlights pic.twitter.com/oQxbkkgvsk
— Jamie (@PhotoChaserJ) September 2, 2025
Forecasts from SWPC indicate continued G1–G2 storming throughout September 2, transitioning to unsettled to active conditions on September 3 as the influence of the CME wanes. By September 4, primarily quiet geomagnetic conditions are expected, with only isolated unsettled periods.
SWPC forecasters estimate a 60% chance of M-class solar flares and a 20% chance of X-class flares on September 2 and 3, decreasing to 55% and 15%, respectively, on September 4.