Solar Activity 24-Hour Summary

Date: 2026 Sep 03 0030 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center

Solar Activity

Solar activity reached moderate levels. Newly numbered Region 4524 (N12E78, Hax/alpha) produced an M3.0 flare at 02/1920 UTC as it rotated onto the visible disk. This event was accompanied by a type II radio sweep with an estimated speed of 1,181 km/s with the associated CME being evident as rapid field line and structural loops departing the eastern limb beginning at approximately 02/1907 UTC in GOES-19 304 imagery. While the bulk of this event is well off the Sun-Earth line, we await sufficient coronagraph imagery to assess any impact of Earth-directed shock.Additional notable activity included a disappearing filament as seen as coronal dimming in GOES-19 195 imagery near 02/0908 UTC. This event may have resulted in the CME first seen in STEREO-A coronagraph imagery at approximately 02/1108 UTC. Modeling of this event indicates that a bulk of the material should be ahead of Earths orbit with a chance for a glancing blow on 07 Sep.

Forecast: Solar activity will likely reach low levels with isolated to occasional C-class flare activity, with a slight chance for M-class flares (R1-R2/Minor-Moderate), through 05 Sep.Energetic Particle The greater than 2 MeV electron flux reached high levels with a peak flux of 2,370 pfu observed at 02/1350 UTC. The greater than 10 MeV proton flux was at background levels.

Forecast: The greater than 2 MeV electron flux is expected to reach high levels through 03 Sep before decreasing to normal to moderate levels on 04-05 Sep. The greater than 10 MeV proton flux is expected to continue at background levels through 05 Sep.

Solar Wind

Solar wind parameters were at nominal levels. Total magnetic field strength ranged 1-6 nT and the Bz component was +/- 4 nT. Solar wind speeds decreased to below 400 km/s and phi became predominantly negative at approximately 02/1141 UTC.

Forecast: Solar wind conditions are expected to largely remain at ambient-like levels through 05 Sep.

Geospace

The geomagnetic field was quiet.

Forecast: Mostly quiet levels are expected to prevail through 05 Sep.