:Product: 1218RSGA.txt :Issued: 2013 Dec 18 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 352 Issued at 2200Z on 18 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: 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 17/2329Z. 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 (19 Dec, 20 Dec, 21 Dec). IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: 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 390 km/s at 18/1444Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one, two, and three (19 Dec, 20 Dec, 21 Dec). III. Event probabilities 19 Dec-21 Dec Class M 30/30/30 Class X 05/05/05 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 18 Dec 156 Predicted 19 Dec-21 Dec 160/160/155 90 Day Mean 18 Dec 139 V. Geomagnetic A Indices Observed Afr/Ap 17 Dec 003/001 Estimated Afr/Ap 18 Dec 004/004 Predicted Afr/Ap 19 Dec-21 Dec 005/005-005/005-005/005 VI. Geomagnetic Activity Probabilities 19 Dec-21 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