:Product: 0521RSGA.txt :Issued: 2018 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 2018 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 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 reached a peak of 425 km/s at 21/0042Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 846 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (22 May, 23 May) and quiet to unsettled levels on day three (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 070 Predicted 22 May-24 May 070/071/071 90 Day Mean 21 May 069 V. Geomagnetic A Indices Observed Afr/Ap 20 May 003/003 Estimated Afr/Ap 21 May 004/004 Predicted Afr/Ap 22 May-24 May 011/012-011/012-007/008 VI. Geomagnetic Activity Probabilities 22 May-24 May A. Middle Latitudes Active 30/30/15 Minor Storm 10/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 30/30/25 Major-severe storm 40/40/25