:Product: 0903RSGA.txt :Issued: 2012 Sep 03 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 247 Issued at 2200Z on 03 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 02/2100Z to 03/2100Z: Solar activity was low. Regions 1560 (N03W33 - Eki/beta-gamma-delta) and 1564 (S16E26 - Esi/beta-gamma) each produced occasional C-class flares. Region 1560 increased in magnetic complexity to a beta-gamma-delta configuration with a delta evident in its interior spots. Region 1564 was in a gradual growth phase during the period and increased in magnetic complexity to a beta-gamma configuration. Region 1553 (S21W82 - Dso/beta) produced occasional optical subflares as it neared the west limb. New Region 1566 (N24E76 - Hax/alpha) was numbered. There were no Earth-directed coronal mass ejections (CME) observed during the period. IB. Solar Activity Forecast: Solar activity is expected to be low through the period (04 - 06 September) with a chance for isolated M- class flares. IIA. Geophysical Activity Summary 02/2100Z to 03/2100Z: Geomagnetic field activity ranged from unsettled to major storm levels with a brief period of severe storm levels detected at high latitudes. An interplanetary shock passed the ACE spacecraft at 03/1123Z indicating the arrival of the Halo CME observed on 31 August. This was followed by a geomagnetic sudden impulse at 03/1214Z (28 nT, Boulder USGS Magnetometer). Field activity increased to major storm levels during 03/1200 - 1500Z following the sudden impulse, then decreased to active levels for the rest of the period, with minor storm periods detected at high latitudes. The greater than 10 MeV proton event at geosynchronous orbit that began at 01/1335Z, reached a maximum of 60 pfu at 02/0850Z, and was in progress as the period ended. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at unsettled to active levels on day 1 (04 September) with a chance for minor storm levels as CME effects wind down. Quiet to unsettled conditions are expected during days 2 - 3 (05 - 06 September) with a chance for active levels due to arrival of Earth-directed CMEs observed on 02 September along with a co-rotating interaction region ahead of a coronal hole high-speed stream (CH HSS). The CH HSS is expected to commence on day 3. The greater than 10 MeV proton event at geosynchronous orbit is expected to end on day 1. III. Event Probabilities 04 Sep-06 Sep Class M 30/30/30 Class X 05/05/05 Proton 50/30/10 PCAF green IV. Penticton 10.7 cm Flux Observed 03 Sep 142 Predicted 04 Sep-06 Sep 140/140/135 90 Day Mean 03 Sep 124 V. Geomagnetic A Indices Observed Afr/Ap 02 Sep 014/015 Estimated Afr/Ap 03 Sep 021/028 Predicted Afr/Ap 04 Sep-06 Sep 014/015-010/012-009/010 VI. Geomagnetic Activity Probabilities 04 Sep-06 Sep A. Middle Latitudes Active 30/20/20 Minor storm 20/05/05 Major-severe storm 05/01/01 B. High Latitudes Active 15/15/15 Minor storm 15/20/30 Major-severe storm 10/20/25