:Product: 0417RSGA.txt :Issued: 2017 Apr 17 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 107 Issued at 2200Z on 17 Apr 2017 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 17/0247Z. There are currently 0 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 and a slight chance for an M-class flare on days one, two, and three (18 Apr, 19 Apr, 20 Apr). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 330 km/s at 17/1332Z. Total IMF reached 5 nT at 17/0439Z. The maximum southward component of Bz reached -4 nT at 17/0511Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1717 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels on day one (18 Apr) and unsettled to active levels on days two and three (19 Apr, 20 Apr). III. Event probabilities 18 Apr-20 Apr Class M 10/15/20 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Apr 075 Predicted 18 Apr-20 Apr 020/018/015 90 Day Mean 17 Apr 078 V. Geomagnetic A Indices Observed Afr/Ap 16 Apr 004/004 Estimated Afr/Ap 17 Apr 008/011 Predicted Afr/Ap 18 Apr-20 Apr 016/020-013/018-012/015 VI. Geomagnetic Activity Probabilities 18 Apr-20 Apr A. Middle Latitudes Active 40/35/40 Minor Storm 20/15/15 Major-severe storm 01/01/01 B. High Latitudes Active 10/10/10 Minor Storm 20/25/25 Major-severe storm 55/50/50