:Product: 0518RSGA.txt :Issued: 2018 May 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 138 Issued at 2200Z on 18 May 2018 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (19 May, 20 May, 21 May). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 478 km/s at 18/0126Z. Total IMF reached 6 nT at 17/2324Z. The maximum southward component of Bz reached -5 nT at 18/0126Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 630 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (19 May, 20 May, 21 May). III. Event probabilities 19 May-21 May Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 May 069 Predicted 19 May-21 May 069/069/068 90 Day Mean 18 May 069 V. Geomagnetic A Indices Observed Afr/Ap 17 May 009/010 Estimated Afr/Ap 18 May 005/005 Predicted Afr/Ap 19 May-21 May 006/005-006/005-006/005 VI. Geomagnetic Activity Probabilities 19 May-21 May A. Middle Latitudes Active 10/10/10 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/15/15 Major-severe storm 10/10/10