:Product: 0904RSGA.txt :Issued: 2012 Sep 04 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 248 Issued at 2200Z on 04 Sep 2012 IA. Analysis of Solar Active Regions and Activity from 03/2100Z to 04/2100Z: Solar activity was low. Region 1564 (S14E14 - Esi/beta-gamma) was the most active region, producing occasional low-level C-class flares. It increased in spot count and area during the first half of the period, but showed gradual spot and penumbral decay during the latter half of the period. Region 1560 (N04W47 - Eai/beta-gamma-delta) showed a slight decrease in spots and area, but maintained a delta in its interior spots. No significant changes were observed in the remaining spotted regions and no new regions were numbered. No Earth-directed CME activity was observed during the period. IB. Solar Activity Forecast: Solar activity is expected to be low through the period (05 - 07 September) with a chance for an isolated M-class flare. IIA. Geophysical Activity Summary 03/2100Z to 04/2100Z: Geomagnetic field activity ranged from quiet to minor storm levels with major storm periods detected at high latitudes, all due to residual CME effects. The greater than 10 MeV proton event at geosynchronous orbit that began at 01/1335Z, reached a maximum of 59 pfu at 02/0850Z, and ended at 04/0625Z. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to unsettled levels during days 1 - 2 (05 - 06 September) with a chance for active levels. This is due to the arrival of CMEs observed on 02 September along with a co-rotating interaction region in advance of a coronal hole high-speed stream (CH HSS). The CMEs are expected to arrive around midday on day 1. The CH HSS is expected to commence on day 2. Field activity is expected to be at quiet to unsettled levels on day 3 (07 September) as CH HSS effects subside. III. Event Probabilities 05 Sep-07 Sep Class M 25/25/25 Class X 01/01/01 Proton 01/01/01 PCAF green IV. Penticton 10.7 cm Flux Observed 04 Sep 138 Predicted 05 Sep-07 Sep 135/135/130 90 Day Mean 04 Sep 124 V. Geomagnetic A Indices Observed Afr/Ap 03 Sep 023/040 Estimated Afr/Ap 04 Sep 012/014 Predicted Afr/Ap 05 Sep-07 Sep 010/012-010/010-007/008 VI. Geomagnetic Activity Probabilities 05 Sep-07 Sep A. Middle Latitudes Active 20/15/15 Minor storm 05/05/01 Major-severe storm 01/01/01 B. High Latitudes Active 15/15/15 Minor storm 30/20/25 Major-severe storm 30/25/20