:Product: 0419RSGA.txt :Issued: 2017 Apr 19 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 109 Issued at 2200Z on 19 Apr 2017 IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: 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 with a chance for a C-class flares and a slight chance for an M-class flare on days one, two, and three (20 Apr, 21 Apr, 22 Apr). IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 487 km/s at 19/1906Z. Total IMF reached 15 nT at 19/2100Z. The maximum southward component of Bz reached -11 nT at 19/0105Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 501 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (20 Apr) and quiet to unsettled levels on days two and three (21 Apr, 22 Apr). III. Event probabilities 20 Apr-22 Apr Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 19 Apr 081 Predicted 20 Apr-22 Apr 085/085/085 90 Day Mean 19 Apr 078 V. Geomagnetic A Indices Observed Afr/Ap 18 Apr 006/006 Estimated Afr/Ap 19 Apr 012/016 Predicted Afr/Ap 20 Apr-22 Apr 012/015-007/008-007/008 VI. Geomagnetic Activity Probabilities 20 Apr-22 Apr A. Middle Latitudes Active 40/25/25 Minor Storm 15/10/10 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/15 Minor Storm 25/25/25 Major-severe storm 50/35/35