:Product: 0920RSGA.txt :Issued: 2013 Sep 20 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 263 Issued at 2200Z on 20 Sep 2013 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 20/1153Z from Region 1850 (N09E62). There are currently 6 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low on days one, two, and three (21 Sep, 22 Sep, 23 Sep). IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: 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 569 km/s at 19/2253Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2939 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (21 Sep, 22 Sep) and quiet to unsettled levels on day three (23 Sep). III. Event probabilities 21 Sep-23 Sep Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 20 Sep 109 Predicted 21 Sep-23 Sep 115/120/115 90 Day Mean 20 Sep 111 V. Geomagnetic A Indices Observed Afr/Ap 19 Sep 014/013 Estimated Afr/Ap 20 Sep 006/007 Predicted Afr/Ap 21 Sep-23 Sep 005/005-005/005-008/002 VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep A. Middle Latitudes Active 05/05/10 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/15/25 Major-severe storm 05/05/10