:Product: 1225RSGA.txt :Issued: 2013 Dec 25 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 359 Issued at 2200Z on 25 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4 event observed at 25/0639Z from old Region 1928 (S16, L=008). There are currently 5 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low with a chance for M-class flares on days one, two, and three (26 Dec, 27 Dec, 28 Dec). IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 338 km/s at 25/0350Z. Total IMF reached 12 nT at 25/0524Z. The maximum southward component of Bz reached -10 nT at 25/1121Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (26 Dec), quiet to unsettled levels on day two (27 Dec) and quiet levels on day three (28 Dec). III. Event probabilities 26 Dec-28 Dec Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 25 Dec 123 Predicted 26 Dec-28 Dec 125/125/125 90 Day Mean 25 Dec 142 V. Geomagnetic A Indices Observed Afr/Ap 24 Dec 002/001 Estimated Afr/Ap 25 Dec 009/009 Predicted Afr/Ap 26 Dec-28 Dec 009/010-009/008-005/005 VI. Geomagnetic Activity Probabilities 26 Dec-28 Dec A. Middle Latitudes Active 25/20/10 Minor Storm 10/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 25/25/15 Major-severe storm 35/25/10