:Product: 1017RSGA.txt :Issued: 2023 Oct 17 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 290 Issued at 2200Z on 17 Oct 2023 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 17/0505Z from Region 3463 (S17W44). There are currently 3 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (18 Oct, 19 Oct, 20 Oct). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 338 km/s at 16/2140Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 166 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 Oct), quiet to minor storm levels on day two (19 Oct) and unsettled to minor storm levels on day three (20 Oct). III. Event probabilities 18 Oct-20 Oct Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Oct 137 Predicted 18 Oct-20 Oct 140/140/140 90 Day Mean 17 Oct 157 V. Geomagnetic A Indices Observed Afr/Ap 16 Oct 003/003 Estimated Afr/Ap 17 Oct 003/004 Predicted Afr/Ap 18 Oct-20 Oct 008/008-014/018-015/022 VI. Geomagnetic Activity Probabilities 18 Oct-20 Oct A. Middle Latitudes Active 15/40/35 Minor Storm 05/25/25 Major-severe storm 01/05/05 B. High Latitudes Active 15/10/10 Minor Storm 25/25/30 Major-severe storm 25/60/55