:Product: 0912RSGA.txt :Issued: 2017 Sep 12 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 255 Issued at 2200Z on 12 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: 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 on days one, two, and three (13 Sep, 14 Sep, 15 Sep). IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 652 km/s at 12/2050Z. Total IMF reached 16 nT at 12/2054Z. The maximum southward component of Bz reached -10 nT at 12/1954Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 872 pfu at 11/2105Z. Protons greater than 100 MeV at geosynchronous orbit reached a peak level of 10 pfu at 11/2115Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 7042 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to major storm levels on day one (13 Sep), unsettled to minor storm levels on day two (14 Sep) and active to minor storm levels on day three (15 Sep). Protons are expected to cross threshold on day one (13 Sep), are expected to cross threshold on day two (14 Sep) and are likely to cross threshold on day three (15 Sep). III. Event probabilities 13 Sep-15 Sep Class M 01/01/01 Class X 01/01/01 Proton 95/80/60 PCAF red IV. Penticton 10.7 cm Flux Observed 12 Sep 076 Predicted 13 Sep-15 Sep 075/075/075 90 Day Mean 12 Sep 081 V. Geomagnetic A Indices Observed Afr/Ap 11 Sep 008/010 Estimated Afr/Ap 12 Sep 010/013 Predicted Afr/Ap 13 Sep-15 Sep 024/036-025/032-021/030 VI. Geomagnetic Activity Probabilities 13 Sep-15 Sep A. Middle Latitudes Active 25/30/30 Minor Storm 35/30/25 Major-severe storm 20/15/15 B. High Latitudes Active 05/05/05 Minor Storm 20/20/20 Major-severe storm 75/65/65