:Product: 0911RSGA.txt :Issued: 2013 Sep 11 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 254 Issued at 2200Z on 11 Sep 2013 IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 4 numbered sunspot regions on the disk. IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (12 Sep, 13 Sep, 14 Sep). IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: 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 417 km/s at 11/1705Z. Total IMF reached 7 nT at 10/2355Z. The maximum southward component of Bz reached -5 nT at 11/0021Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 162 pfu. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (12 Sep) and quiet to active levels on day two (13 Sep) due to coronal hole high speed stream (CH HSS) effects. Quiet to unsettled levels are expected on day three (14 Sep) as CH HSS effects subside. III. Event probabilities 12 Sep-14 Sep Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 11 Sep 093 Predicted 12 Sep-14 Sep 095/095/100 90 Day Mean 11 Sep 114 V. Geomagnetic A Indices Observed Afr/Ap 10 Sep 006/006 Estimated Afr/Ap 11 Sep 008/010 Predicted Afr/Ap 12 Sep-14 Sep 016/020-013/015-008/008 VI. Geomagnetic Activity Probabilities 12 Sep-14 Sep A. Middle Latitudes Active 40/30/10 Minor Storm 15/15/05 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/15 Minor Storm 30/30/25 Major-severe storm 50/45/20