:Product: 1223RSGA.txt :Issued: 2017 Dec 23 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 357 Issued at 2200Z on 23 Dec 2017 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: 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 with a slight chance for a C-class flare on days one, two, and three (24 Dec, 25 Dec, 26 Dec). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 404 km/s at 23/1536Z. Total IMF reached 8 nT at 23/1219Z. The maximum southward component of Bz reached -6 nT at 23/0639Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2813 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on days one and two (24 Dec, 25 Dec) and quiet to unsettled levels on day three (26 Dec). III. Event probabilities 24 Dec-26 Dec Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Dec 076 Predicted 24 Dec-26 Dec 075/075/075 90 Day Mean 23 Dec 075 V. Geomagnetic A Indices Observed Afr/Ap 22 Dec 002/001 Estimated Afr/Ap 23 Dec 005/005 Predicted Afr/Ap 24 Dec-26 Dec 010/012-011/012-007/008 VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec A. Middle Latitudes Active 30/30/20 Minor Storm 10/05/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/20/20 Minor Storm 30/35/30 Major-severe storm 40/35/25