:Product: 0918SGAS.txt :Issued: 2025 Sep 18 0245 UTC # Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Weather Prediction Center and the U.S. Air Force. # Joint USAF/NOAA Solar and Geophysical Activity Summary SGAS Number 261 Issued at 0245Z on 18 Sep 2025 This report is compiled from data received at SWO on 17 Sep A. Energetic Events Begin Max End Rgn Loc Xray Op 245MHz 10cm Sweep 0930 0930 0930 170 1128 1128 1128 1000 1136 1137 1140 4216 N10E03 Sf 320 1213 1219 1221 4216 N10E03 C1.7 Sf 660 1213 1214 1214 360 1523 1524 1539 4220 S17E05 Sf 940 2057 2057 2057 330 2242 2247 2251 4220 C1.6 380 2252 2252 2252 180 B. Proton Events: None. C. Geomagnetic Activity Summary: The geomagnetic field was quiet to unsettled. D. Stratwarm: Not Available E. Daily Indices: (real-time preliminary/estimated values) 10 cm 147 SSN 119 Afr/Ap 010/012 X-ray Background B8.9 Daily Proton Fluence (flux accumulation over 24 hrs) GT 1 MeV 2.2e+06 GT 10 MeV 1.8e+04 p/(cm2-ster-day) (GOES-18 satellite synchronous orbit W137 degrees) Daily Electron Fluence GT 2 MeV 1.80e+08 e/(cm2-ster-day) (GOES-19 satellite synchronous orbit W75 degrees) 3 Hour K-indices: Boulder 2 2 3 3 2 2 2 2 Planetary 2 3 3 3 2 1 2 3 F. Comments: None