:Product: 1219RSGA.txt :Issued: 2015 Dec 19 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 353 Issued at 2200Z on 19 Dec 2015 IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 19/0204Z from Region 2468 (S15W54). There are currently 3 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a slight chance for an M-class flare on days one, two, and three (20 Dec, 21 Dec, 22 Dec). IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 530 km/s at 19/1945Z. Total IMF reached 17 nT at 19/1549Z. The maximum southward component of Bz reached -14 nT at 19/1536Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2825 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (20 Dec), quiet to unsettled levels on day two (21 Dec) and quiet levels on day three (22 Dec). III. Event probabilities 20 Dec-22 Dec Class M 15/15/15 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 19 Dec 119 Predicted 20 Dec-22 Dec 120/125/125 90 Day Mean 19 Dec 109 V. Geomagnetic A Indices Observed Afr/Ap 18 Dec 004/003 Estimated Afr/Ap 19 Dec 010/013 Predicted Afr/Ap 20 Dec-22 Dec 015/018-007/008-006/005 VI. Geomagnetic Activity Probabilities 20 Dec-22 Dec A. Middle Latitudes Active 40/10/10 Minor Storm 20/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 05/20/15 Minor Storm 25/25/20 Major-severe storm 50/15/10