:Product: 0710RSGA.txt :Issued: 2011 Jul 10 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 191 Issued at 2200Z on 10 Jul 2011 IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been at very low levels for the past 24 hours. Region 1247 (S18W15) grew in sunspot count and magnetic complexity but has remained stable and quiet. Region 1250 (S25E48) emerged on the disk early in the period and has grown rapidly to the second largest group on the visible disk. Two CMEs were observed during the period but after careful analysis, both CMEs were determined to be backsided and non-geoeffective. IB. Solar Activity Forecast: Solar activity is expected to be at low levels with a slight chance for M-class events for the next three days (11-13 July) as both Region 1247 and 1250 continue to grow and evolve. IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. The elevated levels are due to the continued effects of a coronal hole high speed stream (CH HSS). Solar wind speeds, as measured by the ACE spacecraft, peaked at around 540 km/s but has since started to decay to around 450 km/s. IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain quiet to unsettled for day one (11 July) as the effects of the CH HSS wane. On day two (12 July), levels ranging from quiet to active are expected due to the combined effects from another CH HSS and the CME observed on 09 July. A return to quiet to unsettled levels is expected on day three (13 July) as effects from both events wane. III. Event Probabilities 11 Jul-13 Jul Class M 10/10/10 Class X 01/01/01 Proton 01/01/01 PCAF Green IV. Penticton 10.7 cm Flux Observed 10 Jul 091 Predicted 11 Jul-13 Jul 092/094/094 90 Day Mean 10 Jul 099 V. Geomagnetic A Indices Observed Afr/Ap 09 Jul 010/012 Estimated Afr/Ap 10 Jul 010/010 Predicted Afr/Ap 11 Jul-13 Jul 007/007-012/012-007/007 VI. Geomagnetic Activity Probabilities 11 Jul-13 Jul A. Middle Latitudes Active 20/30/20 Minor storm 05/10/05 Major-severe storm 01/01/01 B. High Latitudes Active 25/40/25 Minor storm 05/10/05 Major-severe storm 01/01/01