:Product: 1231RSGA.txt :Issued: 2013 Dec 31 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 365 Issued at 2200Z on 31 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C8 event observed at 31/1150Z. There are currently 8 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (01 Jan, 02 Jan, 03 Jan). IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 426 km/s at 31/0012Z. Total IMF reached 6 nT at 31/0605Z. The maximum southward component of Bz reached -4 nT at 31/0745Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and three (01 Jan, 03 Jan) and quiet to minor storm levels on day two (02 Jan). III. Event probabilities 01 Jan-03 Jan Class M 40/40/40 Class X 10/10/10 Proton 05/05/05 PCAF green IV. Penticton 10.7 cm Flux Observed 31 Dec 145 Predicted 01 Jan-03 Jan 150/150/155 90 Day Mean 31 Dec 144 V. Geomagnetic A Indices Observed Afr/Ap 30 Dec 002/002 Estimated Afr/Ap 31 Dec 005/005 Predicted Afr/Ap 01 Jan-03 Jan 009/010-014/018-011/010 VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan A. Middle Latitudes Active 20/30/20 Minor Storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/15/20 Minor Storm 30/25/30 Major-severe storm 25/40/25