Summary and Forecast

Solar Summary

(last updated 26 Apr 2026 23:30 UT)

Activity 26 Apr: R2 Flares Max Fadeout Freq. Sectors M1.3 0023UT possible lower West Pacific M1.4 1403UT possible lower South American/ Atlantic M1.7 1924UT possible lower East Pacific/ North American M2.2 2004UT possible lower East Pacific/ North American M6.0 2257UT probable lower East Pacific/ North American Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Apr: 156/110

Solar Forecast

(last updated 26 Apr 2026 23:30 UT)

27 Apr 28 Apr 29 Apr Activity R2, chance of R3 R2, chance of R3 R2, chance of R3 Fadeouts Probable Probable Probable 10.7cm/SSN 155/109 150/105 150/105 COMMENT: Solar flare activity on UT day 26-Apr was at the R2 level due to an M6.0 flare at 26/2257UT produced by Active Region (AR) 4420 (N16W13, beta-gamma-delta). Four R1 level flares were also observed over the UT day, all of which were produced by regions 4420 and 4425 (N05E52, beta-delta). There are currently six numbered sunspot regions visible on the solar disk. AR 4420 is the largest and most magnetically complex region on the disk. This region has shown spot development in its leader spots, whilst some decay was observed in its trailer spots. Region 4425 has exhibited spot development in its trailer spots over the UT day. All other sunspot regions are either stable or in decay. Solar flare activity is expected to be at the R2 level over 27-29 Apr, with a chance of R3 due to the complexity and observed flare activity of regions 4420 and 4425. S0 solar proton conditions were observed on UT day 26-Apr. S0 solar proton conditions are expected over 27-29 Apr. No Earth-directed coronal mass ejections (CMEs) have been observed, however imagery is not yet available to confirm if there is a CME associated with the M6.0 flare from AR 4420. The solar wind speed on UT day 26-Apr mildly increased, ranging from 410 to 490 km/s and is currently near 460 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 14 nT and the north-south IMF component (Bz) range was -14 to +12 nT. The solar wind speed is expected to decrease over 27-28 Apr, then mildly increase on 29-Apr due to a small southern hemisphere coronal hole.

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