:Product: 0521RSGA.txt :Issued: 2015 May 21 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 141 Issued at 2200Z on 21 May 2015 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 21/0706Z from Region 2349 (S21W10). There are currently 3 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 on days one, two, and three (22 May, 23 May, 24 May). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 468 km/s at 21/1022Z. Total IMF reached 6 nT at 20/2106Z. The maximum southward component of Bz reached -3 nT at 21/1130Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 146 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (22 May, 23 May, 24 May). III. Event probabilities 22 May-24 May Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 May 102 Predicted 22 May-24 May 100/100/100 90 Day Mean 21 May 128 V. Geomagnetic A Indices Observed Afr/Ap 20 May 010/009 Estimated Afr/Ap 21 May 003/004 Predicted Afr/Ap 22 May-24 May 006/005-006/005-006/005 VI. Geomagnetic Activity Probabilities 22 May-24 May A. Middle Latitudes Active 10/10/10 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/20 Minor Storm 20/20/20 Major-severe storm 10/10/10