:Product: 0916RSGA.txt :Issued: 2012 Sep 16 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 Report of Solar and Geophysical Activity SDF Number 260 Issued at 2200Z on 16 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 15/2100Z to 16/2100Z: Solar activity was very low. New Region 1573 (N17E62 - Axx/alpha) produced occasional B-class flares as it rotated into view. Region 1566 (N23W89 - Hrx/alpha) produced a B-class flare as it approached the west limb. Region 1569 (S12W13 - Cso/beta) showed gradual spot and penumbral decay in its intermediate and trailer portions. New Region 1574 (S25W15 - Bxo/beta), a small reverse-polarity group, was also numbered. No Earth-directed CME activity occurred during the period. IB. Solar Activity Forecast: Solar activity is expected to be very low through the period (17 - 19 September) with a chance for a C-class flare. IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z: Geomagnetic field activity was at quiet to unsettled levels. An increase to unsettled levels occurred late in the period associated with the onset of a solar sector boundary crossing (SSBC). Intermittent periods of weakly-southward IMF Bz along with minor increases in solar wind speeds and IMF Bt were associated with the SSBC. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to remain at quiet to unsettled levels on day 1 (17 September) due to minor changes in the solar wind. A decrease to quiet levels is expected on day 2 (18 September). Activity is expected to increase to quiet to unsettled levels on day 3 (19 September), with a slight chance for active levels, as a coronal hole high-speed stream begins to disturb the field. III. Event Probabilities 17 Sep-19 Sep Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 16 Sep 097 Predicted 17 Sep-19 Sep 095/095/100 90 Day Mean 16 Sep 122 V. Geomagnetic A Indices Observed Afr/Ap 15 Sep 005/006 Estimated Afr/Ap 16 Sep 006/008 Predicted Afr/Ap 17 Sep-19 Sep 007/010-006/005-007/008 VI. Geomagnetic Activity Probabilities 17 Sep-19 Sep A. Middle Latitudes Active 10/10/10 Minor storm 01/01/01 Major-severe storm 01/01/01 B. High Latitudes Active 20/15/15 Minor storm 20/15/25 Major-severe storm 10/05/15