:Product: 0420RSGA.txt :Issued: 2014 Apr 20 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 110 Issued at 2200Z on 20 Apr 2014 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6 event observed at 20/0813Z from Region 2033 (N11W84). There are currently 9 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on day one (21 Apr) and expected to be low with a chance for M-class flares on days two and three (22 Apr, 23 Apr). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 765 km/s at 20/1125Z. Total IMF reached 21 nT at 20/1114Z. The maximum southward component of Bz reached -8 nT at 20/1752Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 51 pfu at 19/2310Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 237 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (21 Apr), quiet to active levels on day two (22 Apr) and quiet levels on day three (23 Apr). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (21 Apr, 22 Apr). III. Event probabilities 21 Apr-23 Apr Class M 55/50/50 Class X 10/05/05 Proton 10/10/05 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Apr 163 Predicted 21 Apr-23 Apr 165/160/150 90 Day Mean 20 Apr 156 V. Geomagnetic A Indices Observed Afr/Ap 19 Apr 013/013 Estimated Afr/Ap 20 Apr 016/023 Predicted Afr/Ap 21 Apr-23 Apr 016/020-009/010-007/008 VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr A. Middle Latitudes Active 40/25/20 Minor Storm 25/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 05/15/15 Minor Storm 20/25/20 Major-severe storm 60/30/25