:Product: 0418RSGA.txt :Issued: 2016 Apr 18 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 18 Apr 2016 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M6 event observed at 18/0029Z from Region 2529 (N10W67). There are currently 2 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an M-class flare on day one (19 Apr) and expected to be very low with a chance for a C-class flares and a slight chance for an M-class flare on day two (20 Apr) and expected to be very low with a slight chance for a C-class flare on day three (21 Apr). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 419 km/s at 18/0051Z. Total IMF reached 12 nT at 18/0112Z. The maximum southward component of Bz reached -6 nT at 18/0744Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 207 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (19 Apr), quiet to unsettled levels on day two (20 Apr) and quiet levels on day three (21 Apr). Protons greater than 10 Mev have a slight chance of crossing threshold on day one (19 Apr). III. Event probabilities 19 Apr-21 Apr Class M 20/10/01 Class X 05/01/01 Proton 15/05/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Apr 095 Predicted 19 Apr-21 Apr 095/090/088 90 Day Mean 18 Apr 099 V. Geomagnetic A Indices Observed Afr/Ap 17 Apr 017/021 Estimated Afr/Ap 18 Apr 007/009 Predicted Afr/Ap 19 Apr-21 Apr 010/012-008/008-006/005 VI. Geomagnetic Activity Probabilities 19 Apr-21 Apr A. Middle Latitudes Active 35/15/15 Minor Storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/20/20 Major-severe storm 45/25/20