Summary and Forecast

Solar Summary

(last updated 30 May 2026 23:30 UT)

Activity 30 May: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 30 May: 142/96

Solar Forecast

(last updated 30 May 2026 23:30 UT)

31 May 01 Jun 02 Jun Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 142/96 140/94 136/90 COMMENT: Solar flare activity on UT day 30-May was at the R0 level, with no significant flare activity observed. There are currently nine numbered sunspot regions visible on the solar disk. Active regions (AR) 4449 (S10W14, beta) and 4446 (S13W20, beta) were responsible for some low level C-class flares over the UT day. AR 4451 (S16W00, beta) and 4455 (N14E32, beta) showed spot development over the UT day and 4447 (S17W52, beta) show division in its main spot. None of these regions appear magnetically complex. AR 4452 (N09W57, beta-gamma) is the most magnetically complex region, but appears to be in decay. All other sunspot regions are either stable or in decay. Solar flare activity is expected to be at R0-R1 levels over 31-May to 02-Jun. Solar radiation storm conditions were at the S0 level on 30-May and are expected to remain at the S0 level over 31-May to 02-Jun. No Earth-directed coronal mass ejections (CMEs) have been observed. A fast, north directed CME is visible in SOHO and STEREO-A imagery from 30/0848UT. This CME is considered a far side event and not geoeffective. The solar wind speed increased over the UT day 30-Mar, mostly from 30/1700UT onwards. The wind speed mostly ranged between 370 and 570 km/s . The wind speed is currently at around 500 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 11 nT and the north-south IMF component (Bz) range was -10 to +8 nT. The solar wind speed is expected to remain at current levels over 31-May to 02-Jun, with a chance of an increase on 02-Jun due to a small equatorial coronal hole rotating towards a geoeffective position.

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