:Product: 0918RSGA.txt :Issued: 2017 Sep 18 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 261 Issued at 2200Z on 18 Sep 2017 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 on days one, two, and three (19 Sep, 20 Sep, 21 Sep). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 707 km/s at 18/1034Z. Total IMF reached 7 nT at 17/2101Z. The maximum southward component of Bz reached -5 nT at 18/0056Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 31067 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (19 Sep, 20 Sep) and quiet to unsettled levels on day three (21 Sep). III. Event probabilities 19 Sep-21 Sep Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Sep 072 Predicted 19 Sep-21 Sep 072/072/073 90 Day Mean 18 Sep 081 V. Geomagnetic A Indices Observed Afr/Ap 17 Sep 013/016 Estimated Afr/Ap 18 Sep 019/024 Predicted Afr/Ap 19 Sep-21 Sep 012/014-011/012-007/008 VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep A. Middle Latitudes Active 30/25/20 Minor Storm 15/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/15 Minor Storm 25/25/25 Major-severe storm 50/40/30