Summary and Forecast

Solar Summary

(last updated 31 Aug 2026 23:30 UT)

Activity 31 Aug: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 31 Aug: 107/57

Solar Forecast

(last updated 31 Aug 2026 23:30 UT)

01 Sep 02 Sep 03 Sep Activity R0 R0 R0 Fadeouts None expected None expected None expected 10.7cm/SSN 108/58 106/55 104/53 COMMENT: Solar flare activity on UT day 31-Aug was at the R0 level, with the largest flare of the day a C2.6 flare at 31/1516UT. There are currently two numbered active regions (ARs) on the solar disk and two unnumbered regions. AR 4520 (S12W05, beta) showed spot development over the UT day, but remains magnetically simple. This region was responsible for the largest flare of the day. AR 4518 (N08W19, beta) showed spot decay over the UT day. Two unnumbered regions are present on the solar disk. One has recently developed on the solar disk at around N11W12 and the other has rotated on to the solar disk at around N08E85. Both of these regions show beta magnetic complexity. Solar activity is expected to be at the R0 level over 01-03 Sep. S0 solar radiation storm conditions were observed on UT day 31-Aug and are expected to persist over 01-03 Sep. No geoeffective CMEs have been observed on 31-Aug. A pair of faint, east directed CMEs are visible in SOHO coronagraph imagery from 31/0430UT and 31/0724UT. These events are associated with coronal movement over the eastern limb in GOES SUVI and SDO imagery and are considered far side events. The solar wind speed on UT day 31-Aug declined slightly, mostly ranging between 400 and 475 km/s and is currently around 400 km/s. The peak total interplanetary field strength (IMF, Bt) was 6 nT and the north-south IMF component range (Bz) +5 to -5 nT. The solar wind environment is expected to be mostly near background conditions over 01-03 Sep. There is the chance of a slight increase late on 03-Sep due to a potential impact from a CME first observed on 30-Aug.

Solar Activity levels are explained in the SWS Solar Terrestrial Glossary.