:Product: 1223RSGA.txt :Issued: 2013 Dec 23 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 357 Issued at 2200Z on 23 Dec 2013 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 22/2208Z from Region 1928 (S16W74). There are currently 7 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be moderate with a slight chance for an X-class flare on days one and two (24 Dec, 25 Dec) and expected to be low with a chance for M-class flares on day three (26 Dec). IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: 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 345 km/s at 23/1148Z. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (24 Dec), quiet to active levels on day two (25 Dec) and quiet to unsettled levels on day three (26 Dec). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (24 Dec, 25 Dec). III. Event probabilities 24 Dec-26 Dec Class M 60/60/40 Class X 10/10/05 Proton 10/10/05 PCAF green IV. Penticton 10.7 cm Flux Observed 23 Dec 136 Predicted 24 Dec-26 Dec 135/130/125 90 Day Mean 23 Dec 141 V. Geomagnetic A Indices Observed Afr/Ap 22 Dec 002/001 Estimated Afr/Ap 23 Dec 003/003 Predicted Afr/Ap 24 Dec-26 Dec 005/005-007/010-008/008 VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec A. Middle Latitudes Active 05/25/20 Minor Storm 01/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/25/25 Major-severe storm 05/35/25