Summary and Forecast

Solar Summary

(last updated 10 May 2026 23:30 UT)

Activity 10 May: R2 Flares Max Fadeout Freq. Sectors M5.7 1339UT possible lower European Observed 10.7 cm flux/Equivalent Sunspot Number for 10 May: 126/79

Solar Forecast

(last updated 10 May 2026 23:30 UT)

11 May 12 May 13 May Activity R1-R2 R1-R2 R1-R2 Fadeouts Possible Possible Possible 10.7cm/SSN 128/81 128/81 122/75 COMMENT: Solar flare activity on UT day 10-May was at the R2 level due to an M5.7 flare at 10/1339UT produced by Active Region (AR) 4436 (N18E57, beta). There are currently five numbered sunspot regions visible on the solar disk. AR 4432 (N12W49, beta-gamma) is the most magnetically complex region on the disk and has shown growth in its trailer spots over the UT day. AR 4436 appears mostly stable. All other sunspot regions are either stable or in decay. Solar flare activity is expected to be at R1-R2 levels over 11-13 May, primarily due to the observed activity from region 4436. S0 solar proton conditions were observed on UT day 10-May. S0 solar proton conditions are expected over 11-13 May, with a chance of S1. A broad east-directed coronal mass ejection (CME) was observed, visible in LASCO C2 coronagraph imagery from 10/1348UT. This CME is associated with the aforementioned M5.7 flare from region 4436. Modelling indicates this CME will pass ahead of the Earth. No other Earth-directed CMEs have been observed. The solar wind speed on UT day 10-May decreased, ranging from 460 to 380 km/s and is currently near 380 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 6 nT and the north-south IMF component (Bz) range was -5 to +4 nT. The solar wind speed is expected to remain near background levels over 11-13 May.

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