:Product: 0905RSGA.txt :Issued: 2017 Sep 05 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 248 Issued at 2200Z on 05 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 04/2100Z to 05/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M4 event observed at 05/0108Z. There are currently 6 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (06 Sep, 07 Sep, 08 Sep). IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 629 km/s at 05/0140Z. Total IMF reached 8 nT at 04/2145Z. The maximum southward component of Bz reached -6 nT at 04/2207Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 210 pfu at 05/1930Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 3776 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to severe storm levels on day one (06 Sep), active to severe storm levels on day two (07 Sep) and unsettled to active levels on day three (08 Sep). Protons are expected to cross threshold on day one (06 Sep), are likely to cross threshold on day two (07 Sep) and have a slight chance of crossing threshold on day three (08 Sep). III. Event probabilities 06 Sep-08 Sep Class M 75/75/75 Class X 25/25/25 Proton 99/70/15 PCAF red IV. Penticton 10.7 cm Flux Observed 05 Sep 121 Predicted 06 Sep-08 Sep 120/115/115 90 Day Mean 05 Sep 079 V. Geomagnetic A Indices Observed Afr/Ap 04 Sep 016/017 Estimated Afr/Ap 05 Sep 010/012 Predicted Afr/Ap 06 Sep-08 Sep 022/040-026/048-020/022 VI. Geomagnetic Activity Probabilities 06 Sep-08 Sep A. Middle Latitudes Active 15/15/35 Minor Storm 40/35/15 Major-severe storm 45/50/01 B. High Latitudes Active 01/15/15 Minor Storm 10/35/20 Major-severe storm 90/45/20