:Product: 1218RSGA.txt :Issued: 2018 Dec 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 352 Issued at 2200Z on 18 Dec 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 Dec, 20 Dec, 21 Dec). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 461 km/s at 18/1631Z. Total IMF reached 7 nT at 18/0018Z. The maximum southward component of Bz reached -5 nT at 18/1300Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 170 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (19 Dec) and quiet levels on days two and three (20 Dec, 21 Dec). III. Event probabilities 19 Dec-21 Dec Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Dec 070 Predicted 19 Dec-21 Dec 070/070/070 90 Day Mean 18 Dec 069 V. Geomagnetic A Indices Observed Afr/Ap 17 Dec 005/003 Estimated Afr/Ap 18 Dec 007/008 Predicted Afr/Ap 19 Dec-21 Dec 008/008-005/005-006/005 VI. Geomagnetic Activity Probabilities 19 Dec-21 Dec A. Middle Latitudes Active 20/10/10 Minor Storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 20/20/15 Minor Storm 25/20/15 Major-severe storm 25/15/15