Summary and Forecast

Solar Summary

(last updated 23 Aug 2026 23:30 UT)

Activity 23 Aug: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Aug: 128/81

Solar Forecast

(last updated 23 Aug 2026 23:30 UT)

24 Aug 25 Aug 26 Aug Activity R0 R0 R0 Fadeouts Possible Possible Possible 10.7cm/SSN 125/78 120/72 120/72 COMMENT: Solar flare activity on UT day 23-Aug was at the R0 level, with a C4.2 flare at 0652UT the largest flare of the UT day. There are currently four numbered active regions (ARs) visible on the solar disk. AR 4513 (N04E28, beta-gamma-delta) is the largest and most magenetically complex region on the solar disk and has a history of M-class flare production. This region was responsible for the largest flare of the UT day and showed some east-west expansion over the day. AR 4517 (N09E13, beta) developed over the UT day, but is still magnetically simple. The other two regions are stable and simple. Solar flare activity is expected to be at R0-R1 levels over 24-26 Aug due to the magnetic complexity of 4513 and its recent flare activity. Solar radiation storm conditions were at the S0 level on 23-Aug, with the >10 MeV proton flux raised but below threshold. S0 conditions are expected over 24-26 Aug, with a chance of S1 over 24-25 Aug due to the currently enhanced >10 MeV proton flux. The enhanced proton conditions are due to a long duration flare observed on 21-Aug. No Earth-directed coronal mass ejections (CMEs) have been observed. The solar wind speed on UT day 23-Aug decreased as coronal hole high speed wind stream effects waned, ranging between 380 and 450 km/s, and is currently near 385 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 6 nT and the north-south IMF component (Bz) range was -4 to +4 nT. The solar wind speed is expected to continue to decline towards background levels and remain there over 24-26 Aug as coronal hole high speed wind stream effects wane.

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