:Product: 1217RSGA.txt :Issued: 2013 Dec 18 0500 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 350 Issued at 2200Z on 17 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C2 event observed at 16/1733Z. There are currently 6 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for an M-class flare on days one, two, and three (18 Dec, 19 Dec, 20 Dec). IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: 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 448 km/s at 17/1502Z. Total IMF reached 4 nT at 17/1646Z. The maximum southward component of Bz reached -4 nT at 17/1647Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (18 Dec, 19 Dec, 20 Dec). III. Event probabilities 18 Dec-20 Dec Class M 25/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 17 Dec 159 Predicted 18 Dec-20 Dec 160/155/160 90 Day Mean 17 Dec 139 V. Geomagnetic A Indices Observed Afr/Ap 16 Dec 005/004 Estimated Afr/Ap 17 Dec 003/001 Predicted Afr/Ap 18 Dec-20 Dec 005/007-005/005-005/005 VI. Geomagnetic Activity Probabilities 18 Dec-20 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