:Product: 0921RSGA.txt :Issued: 2017 Sep 21 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 264 Issued at 2200Z on 21 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 day one (22 Sep) and likely to be low with a slight chance for an M-class flare on days two and three (23 Sep, 24 Sep). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 472 km/s at 21/0212Z. Total IMF reached 5 nT at 21/2058Z. The maximum southward component of Bz reached -4 nT at 21/1723Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 30386 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (22 Sep), quiet to unsettled levels on day two (23 Sep) and quiet to active levels on day three (24 Sep). III. Event probabilities 22 Sep-24 Sep Class M 01/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Sep 073 Predicted 22 Sep-24 Sep 070/085/090 90 Day Mean 21 Sep 081 V. Geomagnetic A Indices Observed Afr/Ap 20 Sep 008/009 Estimated Afr/Ap 21 Sep 007/007 Predicted Afr/Ap 22 Sep-24 Sep 006/005-007/008-009/012 VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep A. Middle Latitudes Active 10/20/25 Minor Storm 01/05/10 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/25/25 Major-severe storm 15/30/40