:Product: 0831RSGA.txt :Issued: 2017 Aug 31 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 243 Issued at 2200Z on 31 Aug 2017 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 30/2311Z from Region 2674 (N14E64). There are currently 4 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 (01 Sep, 02 Sep, 03 Sep). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 719 km/s at 31/1217Z. Total IMF reached 31 nT at 31/0618Z. The maximum southward component of Bz reached -19 nT at 31/0539Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (01 Sep), quiet to active levels on day two (02 Sep) and quiet to unsettled levels on day three (03 Sep). III. Event probabilities 01 Sep-03 Sep Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Aug 092 Predicted 01 Sep-03 Sep 092/092/091 90 Day Mean 31 Aug 077 V. Geomagnetic A Indices Observed Afr/Ap 30 Aug 005/005 Estimated Afr/Ap 31 Aug 025/034 Predicted Afr/Ap 01 Sep-03 Sep 016/024-015/016-012/012 VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep A. Middle Latitudes Active 35/30/25 Minor Storm 35/10/10 Major-severe storm 10/01/01 B. High Latitudes Active 20/15/15 Minor Storm 20/20/20 Major-severe storm 20/20/20