:Product: 1227RSGA.txt :Issued: 2013 Dec 27 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 361 Issued at 2200Z on 27 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 26/2100Z to 27/2100Z: 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 27/1213Z from Region 1936 (S16E19). There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (28 Dec, 29 Dec, 30 Dec). IIA. Geophysical Activity Summary 26/2100Z to 27/2100Z: 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 335 km/s at 27/1908Z. Total IMF reached 9 nT at 27/1701Z. The maximum southward component of Bz reached -4 nT at 27/1858Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 2 pfu at 27/0250Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (28 Dec, 29 Dec, 30 Dec). III. Event probabilities 28 Dec-30 Dec Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 27 Dec 131 Predicted 28 Dec-30 Dec 135/135/135 90 Day Mean 27 Dec 142 V. Geomagnetic A Indices Observed Afr/Ap 26 Dec 002/002 Estimated Afr/Ap 27 Dec 003/005 Predicted Afr/Ap 28 Dec-30 Dec 005/005-006/005-006/005 VI. Geomagnetic Activity Probabilities 28 Dec-30 Dec A. Middle Latitudes Active 05/05/05 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/15/15 Major-severe storm 05/05/05