Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 138 Issued at 2200Z on 18 May 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 2 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 (19 May, 20 May, 21 May).
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 458 km/s at 17/2148Z. Total IMF reached 9 nT at 18/1717Z. The maximum southward component of Bz reached -6 nT at 18/0338Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 149 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to major storm levels on day one (19 May), active to minor storm levels on day two (20 May) and quiet to active levels on day three (21 May).
III. Event probabilities 19 May-21 May Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green
IV. Penticton 10.7 cm Flux Observed 18 May 072 Predicted 19 May-21 May 072/072/072 90 Day Mean 18 May 077
V. Geomagnetic A Indices Observed Afr/Ap 17 May 009/009 Estimated Afr/Ap 18 May 013/018 Predicted Afr/Ap 19 May-21 May 031/045-024/030-016/020
VI. Geomagnetic Activity Probabilities 19 May-21 May A. Middle Latitudes Active 30/40/20 Minor Storm 35/20/05 Major-severe storm 15/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/20/15 Major-severe storm 20/15/10