:Product: 0420RSGA.txt :Issued: 2013 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 2013 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 C1 event observed at 20/0036Z. There are currently 6 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a chance for an M-class flare on all three days (21-23 Apr). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft remained around 300km/s. Total IMF reached 6 nT at 20/1925Z. The maximum southward component of Bz reached -4 nT at 20/1039Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 116 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (21 Apr), quiet to unsettled levels on day two (22 Apr) and quiet to active levels on day three (23 Apr). III. Event probabilities 21 Apr-23 Apr Class M 10/10/10 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Apr 105 Predicted 21 Apr-23 Apr 105/105/105 90 Day Mean 20 Apr 111 V. Geomagnetic A Indices Observed Afr/Ap 19 Apr 001/002 Estimated Afr/Ap 20 Apr 003/004 Predicted Afr/Ap 21 Apr-23 Apr 004/005-006/008-008/012 VI. Geomagnetic Activity Probabilities 21 Apr-23 Apr A. Middle Latitudes Active 10/15/25 Minor Storm 01/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/20/30 Major-severe storm 10/20/30