:Product: 0818RSGA.txt :Issued: 2017 Aug 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 230 Issued at 2200Z on 18 Aug 2017 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on days one and two (19 Aug, 20 Aug) and expected to be very low with a chance for a C-class flares on day three (21 Aug). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 685 km/s at 18/0659Z. Total IMF reached 8 nT at 18/0101Z. The maximum southward component of Bz reached -7 nT at 18/0025Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1170 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one, two, and three (19 Aug, 20 Aug, 21 Aug). III. Event probabilities 19 Aug-21 Aug Class M 10/10/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Aug 080 Predicted 19 Aug-21 Aug 082/084/085 90 Day Mean 18 Aug 076 V. Geomagnetic A Indices Observed Afr/Ap 17 Aug 020/028 Estimated Afr/Ap 18 Aug 016/022 Predicted Afr/Ap 19 Aug-21 Aug 015/018-012/015-011/012 VI. Geomagnetic Activity Probabilities 19 Aug-21 Aug A. Middle Latitudes Active 30/25/15 Minor Storm 10/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/15 Minor Storm 30/30/30 Major-severe storm 45/40/25