


Routine Space Environment Product Issued Weekly
Issued by NWS
Issued by NWS
Versions:
1
384 FXXX06 KWNP 080256 WEKHIL :Product: 7-day Space Weather Highlights :Issued: 2025 Sep 08 0224 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # https://www.swpc.noaa.gov/content/subscription-services # # 7-day Space Weather Highlights # Highlights of Solar and Geomagnetic Activity 01 - 07 September 2025 Solar activity reached moderate levels (R1-MInor) over 04 Sep, 05 Sep, and 06 Sep. All M-class flares were attributed to Region 4207 (S29, L=045, class/area=Fhi/390 on 04 Sep). The remaining 17 numbered active regions on the visible disk in the past week were either quiet or only produced C-class events. Other significant activity included a CME that erupted from a filament centered near N12W04 around 04/1945 UTC. This resulted in a halo CME signature in subsequent coronagraph imagery. Initial modelling of the event suggested arrival early on the 07 Sep. Observed arrival was mid-to-late on 06 Sep. The proton flux at geosynchronous orbit remained below the S1 (Minor) threshold. The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels. Geomagnetic field activity was ranged from quiet to G2 (Moderate) levels. G2 conditions observed on 01 Sep were attributed to the onset of a CME that left the Sun on 30 Aug. Total magnetic field strength reached a peak of 25 nT and the Bz component was observed as far south as -23 nT at 02/0000 UTC. Shock arrival at ACE was observed at 01/2030 UTC, marked by a solar wind speed increase from ~410 km/s to ~645 km/s. A sudden impulse was observed at Earth at 01/2101 UTC. G1 (Minor) activity was observed on 02 and 03 Sep during the waning phase off the CME. Quiet conditions were observed over 04-05 Sep. An increase in activity was observed on 06 Sep, with a G1 period marking the arrival of a CME that left the Sun on 04 Sep. Total magnetic field strength reached an initial peak of 21 nT at 06/1407 UTC. The Bz component rotated as far south as -10 nT. The solar wind speeds increased to ~700 km/s. The Bz component rotated northward shortly after which resulted in mostly quiet conditions ov07 Sep during the waning phase of the CME.