Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 231 Issued at 2200Z on 19 Aug 2017
IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 19/0137Z. There are currently 1 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (20 Aug, 21 Aug, 22 Aug).
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at unsettled to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 814 km/s at 19/1630Z. Total IMF reached 7 nT at 19/0624Z. The maximum southward component of Bz reached -7 nT at 19/0709Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 8118 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (20 Aug) and quiet to active levels on days two and three (21 Aug, 22 Aug).
III. Event probabilities 20 Aug-22 Aug Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green
IV. Penticton 10.7 cm Flux Observed 19 Aug 087 Predicted 20 Aug-22 Aug 088/090/090 90 Day Mean 19 Aug 076
V. Geomagnetic A Indices Observed Afr/Ap 18 Aug 020/024 Estimated Afr/Ap 19 Aug 023/032 Predicted Afr/Ap 20 Aug-22 Aug 017/022-012/015-011/012
VI. Geomagnetic Activity Probabilities 20 Aug-22 Aug A. Middle Latitudes Active 35/25/15 Minor Storm 10/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/20 Minor Storm 30/30/30 Major-severe storm 50/35/25