:Product: 0930RSGA.txt :Issued: 2012 Sep 30 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 274 Issued at 2200Z on 30 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 29/2100Z to 30/2100Z: Solar activity has been at moderate levels for the past 24 hours with Region 1583 (N12W88) producing an isolated M1 solar x-ray event at 0433Z. Region 1583 had grown rapidly in the past 24 hours, however it is only hours away from rotating off the solar disk and out of view. The remaining active regions on the disk remained stable, producing a few low level C-class events. New Region 1584 (S23E28) was numbered early in the period, and at the time of this report, had only produced one low level C-class event. No Earth directed CMEs were observed in the past 24 hours. IB. Solar Activity Forecast: Solar activity is expected to be at low levels with a slight chance for continued M-class activity for the next two days (01 - 02 October). A return to low levels is expected on day three (03 October), as the active region cluster, located in the northwest quadrant, rotates around the west limb. IIA. Geophysical Activity Summary 29/2100Z to 30/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. The enhanced activity was due to the arrival of a CME from 27 September. At around 1100Z, measurements from the ACE spacecraft, indicated the arrival of this CME. At 1138Z, a sudden impulse of 15 nT was measured by the Boulder magnetometer, as the CME reached Earth. Solar wind velocities increased very little with this initial phase of the CME, increasing from around 280 - 320 km/s. The total IMF increased as the CME arrived, with sustained periods of negative Bz. However, with the lower than expected solar wind speeds, very little geomagnetic effects have been observed. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels with minor storm periods possible on day one (01 October), as effects of todays CME continue. Quiet to unsettled levels are expected on day two (02 October) as CME effects wane. A return to predominantly quiet levels is expected on day three (03 October). III. Event Probabilities 01 Oct-03 Oct Class M 10/10/01 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 30 Sep 136 Predicted 01 Oct-03 Oct 130/130/125 90 Day Mean 30 Sep 124 V. Geomagnetic A Indices Observed Afr/Ap 29 Sep 004/004 Estimated Afr/Ap 30 Sep 009/011 Predicted Afr/Ap 01 Oct-03 Oct 011/015-007/008-004/005 VI. Geomagnetic Activity Probabilities 01 Oct-03 Oct A. Middle Latitudes Active 35/10/05 Minor storm 15/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 10/15/15 Minor storm 25/20/15 Major-severe storm 50/20/10