:Product: 0823RSGA.txt :Issued: 2017 Aug 23 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 235 Issued at 2200Z on 23 Aug 2017 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: 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 23/1343Z from Region 2672 (N08E34). There are currently 2 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 (24 Aug, 25 Aug, 26 Aug). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 510 km/s at 23/1755Z. Total IMF reached 7 nT at 23/0942Z. The maximum southward component of Bz reached -6 nT at 23/1655Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3710 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (24 Aug), quiet to unsettled levels on day two (25 Aug) and quiet levels on day three (26 Aug). III. Event probabilities 24 Aug-26 Aug Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Aug 085 Predicted 24 Aug-26 Aug 085/085/085 90 Day Mean 23 Aug 076 V. Geomagnetic A Indices Observed Afr/Ap 22 Aug 016/023 Estimated Afr/Ap 23 Aug 018/025 Predicted Afr/Ap 24 Aug-26 Aug 011/014-007/008-006/005 VI. Geomagnetic Activity Probabilities 24 Aug-26 Aug A. Middle Latitudes Active 35/15/10 Minor Storm 15/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/20/15 Major-severe storm 35/15/15