:Product: 0913RSGA.txt :Issued: 2017 Sep 13 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 256 Issued at 2200Z on 13 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: 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 slight chance for a C-class flare on days one, two, and three (14 Sep, 15 Sep, 16 Sep). IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 656 km/s at 12/2116Z. Total IMF reached 16 nT at 12/2129Z. The maximum southward component of Bz reached -12 nT at 12/2257Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 138 pfu at 12/2100Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2410 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on days one and two (14 Sep, 15 Sep) and unsettled to active levels on day three (16 Sep). Protons are expected to cross threshold on day one (14 Sep), are expected to cross threshold on day two (15 Sep) and are likely to cross threshold on day three (16 Sep). III. Event probabilities 14 Sep-16 Sep Class M 01/01/01 Class X 01/01/01 Proton 95/80/60 PCAF red IV. Penticton 10.7 cm Flux Observed 13 Sep 075 Predicted 14 Sep-16 Sep 075/075/075 90 Day Mean 13 Sep 081 V. Geomagnetic A Indices Observed Afr/Ap 12 Sep 016/016 Estimated Afr/Ap 13 Sep 021/028 Predicted Afr/Ap 14 Sep-16 Sep 021/028-020/026-018/020 VI. Geomagnetic Activity Probabilities 14 Sep-16 Sep A. Middle Latitudes Active 30/35/30 Minor Storm 30/25/15 Major-severe storm 15/05/01 B. High Latitudes Active 05/10/10 Minor Storm 20/20/25 Major-severe storm 65/60/50