:Product: Report of Solar-Geophysical Activity :Issued: 2010 Jul 25 2201 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 206 Issued at 2200Z on 25 Jul 2010 IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was very low. A single low-level B-class flare occurred. Region 1089 (S24W08) continued a gradual decrease in area and spot number. No new regions were assigned. IB. Solar Activity Forecast: Solar activity is expected to be very low. However, there is a slight chance for an isolated C-class flare from Region 1089. IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: Geomagnetic field activity was at quiet to briefly unsettled levels. ACE solar wind readings indicated velocities gradually increased from 333 to 483 km/s during the period. The enhanced velocities were associated with a recurrent coronal hole high-speed stream. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at quiet to unsettled levels on day 1 (26 July). Activity is expected to increase to unsettled to active levels with a slight chance for minor storm levels on day 2 (27 July) as the recurrent coronal hole high-speed wind stream intensifies. Activity is expected to decrease to quiet to unsettled levels on day 3 (28 July) as coronal hole effects gradually subside. III. Event Probabilities 26 Jul-28 Jul Class M 01/01/01 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 25 Jul 085 Predicted 26 Jul-28 Jul 084/084/082 90 Day Mean 25 Jul 075 V. Geomagnetic A Indices Observed Afr/Ap 24 Jul 004/005 Estimated Afr/Ap 25 Jul 006/008 Predicted Afr/Ap 26 Jul-28 Jul 008/010-012/015-008/010 VI. Geomagnetic Activity Probabilities 26 Jul-28 Jul A. Middle Latitudes Active 15/25/15 Minor storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 20/30/20 Minor storm 05/15/05 Major-severe storm 01/05/01