:Product: 0929RSGA.txt :Issued: 2012 Sep 29 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 273 Issued at 2200Z on 29 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 28/2100Z to 29/2100Z: Solar activity was at low levels. Numerous weak C-class events were observed during the past 24 hours, mostly from Regions 1575 (N07W73) and 1577 (N09W54). New Region 1583 (N13W75) emerged on the disk as a simple bipolar group. No significant changes were observed from the remainder of the disk and limb. No Earth-directed CMEs were observed during the period. IB. Solar Activity Forecast: Solar activity is expected to be at low levels with a slight chance for M-class activity all three days of the forecast period (30 September - 02 October). IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z: The geomagnetic field was at quiet levels. ACE satellite measurements indicated a steady decline in wind speed from about 325 km/s to near 275 km/s while the Bz component of the interplanetary magnetic field did not vary much beyond +/- 3 nT. At about 29/0100Z, a solar sector boundary crossing from a negative (toward) to a positive (away) orientation was observed. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at predominately quiet levels through about midday on day one (30 September). By late on day one, active levels with a chance for minor to major storm periods are expected due to the arrival of the Earth-directed CME observed early on 28 September. On day two (01 October), continued minor to major storm conditions are expected early in the day, decreasing to mostly quiet to unsettled levels with a chance for isolated active periods as effects from the CME wane. Predominately quiet to unsettled conditions are expected on day three (02 October). III. Event Probabilities 30 Sep-02 Oct Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 29 Sep 136 Predicted 30 Sep-02 Oct 135/130/125 90 Day Mean 29 Sep 125 V. Geomagnetic A Indices Observed Afr/Ap 28 Sep 002/003 Estimated Afr/Ap 29 Sep 004/004 Predicted Afr/Ap 30 Sep-02 Oct 018/035-018/025-007/008 VI. Geomagnetic Activity Probabilities 30 Sep-02 Oct A. Middle Latitudes Active 35/35/10 Minor storm 25/30/05 Major-severe storm 05/10/01 B. High Latitudes Active 10/10/15 Minor storm 25/20/20 Major-severe storm 60/70/20