Summary and Forecast

Solar Summary

(last updated 13 May 2026 23:30 UT)

Activity 13 May: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 13 May: 103/52

Solar Forecast

(last updated 13 May 2026 23:30 UT)

14 May 15 May 16 May Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 105/54 100/48 100/48 COMMENT: Solar flare activity on UT day 13-May was at the R0 level, with only low level C-class flares observed. There are currently four numbered sunspot regions visible on the solar disk. Active Region (AR) 4436 (N20E20, beta-delta) is the most magnetically complex region on the disk. This region has shown mild growth in its trailer spots, while the eastern of the two main spots has now separated into three spots. AR 4435 (N23W51, beta) has shown mild growth in its trailer spots. All other sunspot regions are either stable or in decay. Solar flare activity is expected to be at R0-R1 levels over 14-16 May. S0 solar proton conditions were observed on UT day 13-May. S0 solar proton conditions are expected over 14-16 May. No Earth-directed coronal mass ejections (CMEs) have been observed. The solar wind speed on UT day 13-May increased, ranging from 325 to 500 km/s and is currently near 455 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 14 nT and the north-south IMF component (Bz) range was -9 to +13 nT. The solar wind speed is expected to remain elevated on 14-May, then increase over 15-16 May due to coronal hole high speed wind stream effects from an equatorial coronal hole.

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