:Product: 0918RSGA.txt :Issued: 2025 Sep 18 2200 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 Geophysical Activity Report and Forecast SDF Number 261 Issued at 2200Z on 18 Sep 2025 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at low levels for the past 24 hours. There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (19 Sep, 20 Sep, 21 Sep). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 614 km/s at 18/0328Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 6213 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (19 Sep, 20 Sep) and quiet to active levels on day three (21 Sep). III. Event probabilities 19 Sep-21 Sep Class M 35/35/35 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Sep 150 Predicted 19 Sep-21 Sep 150/150/150 90 Day Mean 18 Sep 144 V. Geomagnetic A Indices Observed Afr/Ap 17 Sep 010/012 Estimated Afr/Ap 18 Sep 007/007 Predicted Afr/Ap 19 Sep-21 Sep 006/005-006/005-012/015 VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep A. Middle Latitudes Active 10/10/30 Minor Storm 01/01/10 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/20/30 Major-severe storm 20/20/40