:Product: 0920RSGA.txt :Issued: 2017 Sep 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 263 Issued at 2200Z on 20 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 2 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (21 Sep, 22 Sep, 23 Sep). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 533 km/s at 19/2118Z. Total IMF reached 6 nT at 20/2016Z. The maximum southward component of Bz reached -4 nT at 20/1158Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 33761 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (21 Sep, 23 Sep) and quiet levels on day two (22 Sep). III. Event probabilities 21 Sep-23 Sep Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Sep 074 Predicted 21 Sep-23 Sep 074/073/075 90 Day Mean 20 Sep 081 V. Geomagnetic A Indices Observed Afr/Ap 19 Sep 006/008 Estimated Afr/Ap 20 Sep 009/011 Predicted Afr/Ap 21 Sep-23 Sep 007/008-006/005-007/008 VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep A. Middle Latitudes Active 20/10/20 Minor Storm 05/01/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/20/25 Major-severe storm 30/20/30