Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 148 Issued at 2200Z on 28 May 2017
IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: 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 28/1928Z from Region 2659 (N13W70). There are currently 1 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a chance for a C-class flares on days one and two (29 May, 30 May) and expected to be very low with a slight chance for a C-class flare on day three (31 May).
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet to severe storm levels for the past 24 hours. Solar wind speed reached a peak of 463 km/s at 27/2243Z. Total IMF reached 23 nT at 27/2222Z. The maximum southward component of Bz reached -20 nT at 27/2222Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 641 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (29 May) and quiet levels on days two and three (30 May, 31 May).
III. Event probabilities 29 May-31 May Class M 05/05/01 Class X 01/01/01 Proton 01/01/01 PCAF green
IV. Penticton 10.7 cm Flux Observed 28 May 079 Predicted 29 May-31 May 078/072/070 90 Day Mean 28 May 076
V. Geomagnetic A Indices Observed Afr/Ap 27 May 014/017 Estimated Afr/Ap 28 May 036/060 Predicted Afr/Ap 29 May-31 May 012/012-005/005-005/005
VI. Geomagnetic Activity Probabilities 29 May-31 May A. Middle Latitudes Active 20/10/10 Minor Storm 05/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 20/15/15 Major-severe storm 15/10/10