:Product: 0820RSGA.txt :Issued: 2015 Aug 20 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 232 Issued at 2200Z on 20 Aug 2015 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 20/0526Z from Region 2403 (S13E37). There are currently 3 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on days one, two, and three (21 Aug, 22 Aug, 23 Aug). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 566 km/s at 20/0813Z. Total IMF reached 7 nT at 20/1140Z. The maximum southward component of Bz reached -6 nT at 20/1049Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 8392 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (21 Aug, 22 Aug) and unsettled to minor storm levels on day three (23 Aug). III. Event probabilities 21 Aug-23 Aug Class M 15/15/15 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Aug 103 Predicted 21 Aug-23 Aug 105/110/115 90 Day Mean 20 Aug 110 V. Geomagnetic A Indices Observed Afr/Ap 19 Aug 018/019 Estimated Afr/Ap 20 Aug 009/013 Predicted Afr/Ap 21 Aug-23 Aug 010/012-009/012-021/028 VI. Geomagnetic Activity Probabilities 21 Aug-23 Aug A. Middle Latitudes Active 30/25/45 Minor Storm 05/05/25 Major-severe storm 01/01/05 B. High Latitudes Active 15/20/05 Minor Storm 35/35/25 Major-severe storm 40/30/70