:Product: 0921RSGA.txt :Issued: 2013 Sep 21 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 264 Issued at 2200Z on 21 Sep 2013 IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: 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 21/0924Z from Region 1850 (N08E52). There are currently 5 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is likely to be low on days one, two, and three (22 Sep, 23 Sep, 24 Sep). IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 470 km/s at 20/2137Z. Total IMF reached 5 nT at 21/1732Z. The maximum southward component of Bz reached -4 nT at 21/0722Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 2810 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (22 Sep) and quiet to unsettled levels on days two and three (23 Sep, 24 Sep). III. Event probabilities 22 Sep-24 Sep Class M 05/05/05 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 21 Sep 110 Predicted 22 Sep-24 Sep 115/118/115 90 Day Mean 21 Sep 111 V. Geomagnetic A Indices Observed Afr/Ap 20 Sep 005/006 Estimated Afr/Ap 21 Sep 008/007 Predicted Afr/Ap 22 Sep-24 Sep 005/005-008/008-008/008 VI. Geomagnetic Activity Probabilities 22 Sep-24 Sep A. Middle Latitudes Active 05/10/10 Minor Storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor Storm 15/25/25 Major-severe storm 05/10/10