Summary and Forecast

Solar Summary

(last updated 23 May 2026 23:30 UT)

Activity 23 May: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 23 May: 137/91

Solar Forecast

(last updated 23 May 2026 23:30 UT)

24 May 25 May 26 May Activity R0, chance of R1 R0, chance of R1 R0, chance of R1 Fadeouts Possible Possible Possible 10.7cm/SSN 140/94 145/99 145/99 COMMENT: Solar flare activity on UT day 23-May was at the R0 level, with no significant flaring activity. There are currently five numbered sunspot regions on the solar disk. Active Region (AR) 4441 (N08W65, beta) is the largest region on the disk and has shown consolidation of intermediate spots and mild decay in its trailer spots. AR4444 (S19E42, beta gamma) has showed development in its leader spots over the UT day. All other sunspot regions are either stable or in decay. Solar flare activity is expected to be at the R0 level over 24-26 May, with a chance of R1. S0 solar radiation conditions were observed on UT day 23-May. S0 solar radiation conditions are expected over 24-26 May. No Earth-directed coronal mass ejections (CMEs) were observed on 23-May. Two northwest-directed CME's was observed in LASCO C2 coronagraph imagery at 23/0648UT and 23/1612UT, both are attributed to far side eruptions. The solar wind speed decreased over 23-May. The speed ranged from 320 to 370 km/s and is currently near 330 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 5 nT and the north-south IMF component (Bz) range was -3 to +4 nT. The solar wind speed is expected to remain at background levels over 24-25 May and may increase 26 May as a southern hemisphere coronal hole moves into a geoeffective position.

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