:Product: 0820RSGA.txt :Issued: 2011 Aug 20 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 232 Issued at 2200Z on 20 Aug 2011 IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. There were occasional B-class flares from Regions 1272 (S22E15) and 1271 (N16E10). Region 1271 decayed slightly to become a Dso type spot group with Beta magnetic configuration. Region 1274 (N19E70) was numbered today; it is currently small and magnetically simple. IB. Solar Activity Forecast: Solar activity is expected to be very low to low on Day 1 (21 Aug), becoming low with a slight chance for moderate activity on Days 2 and 3 (22-23 Aug) with four active regions expected to be on the disk at that time. IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet and the solar wind at the ACE spacecraft was unremarkable. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled on Day 1 (21 Aug) rising to unsettled with a chance for active conditions on Day 2 (22 Aug). The increase in activity is expected due to a co-rotating interaction region followed by two negative polarity coronal hole high speed streams. Day 3 (23 Aug) is expected to return to quiet to unsettled conditions as effects from the first coronal hole begin to wane. III. Event Probabilities 21 Aug-23 Aug Class M 05/20/20 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 20 Aug 101 Predicted 21 Aug-23 Aug 102/104/105 90 Day Mean 20 Aug 096 V. Geomagnetic A Indices Observed Afr/Ap 19 Aug 001/002 Estimated Afr/Ap 20 Aug 003/003 Predicted Afr/Ap 21 Aug-23 Aug 007/008-010/012-007/008 VI. Geomagnetic Activity Probabilities 21 Aug-23 Aug A. Middle Latitudes Active 15/25/15 Minor storm 05/10/05 Major-severe storm 01/05/01 B. High Latitudes Active 30/40/30 Minor storm 15/20/15 Major-severe storm 05/10/05