Summary and Forecast
Solar Summary
(last updated 23 Apr 2026 23:30 UT)
Activity 23 Apr: R1 Flares Max Fadeout Freq. Sectors M1.6 0435UT possible lower E. Asia/Aust. M4.3 0848UT possible lower Mid East/Indian M1.7 1400UT possible lower South American/ Atlantic M4.9 1708UT possible lower South American/ Atlantic Observed 10.7 cm flux/Equivalent Sunspot Number for 23 Apr: 128/81
Solar Forecast
(last updated 23 Apr 2026 23:30 UT)
24 Apr 25 Apr 26 Apr Activity R1, chance of R2 R1, chance of R2 R1, chance of R2 Fadeouts Possible Possible Possible 10.7cm/SSN 135/89 135/89 132/86 COMMENT: Solar flare activity reached the R1 level on UT day 23-Apr, with five M-class flares observed throught the UT day. The largest of these flares was an M4.9 flare from AR 4419 (N15W64, beta), peaking at 23/1708UT. AR 4419 also produced an M1.6, an M4.3, and an M1.7 flare, which peaked at 23/0435UT, 23/0848UT, and 23/1400UT, respectively. Additionally, an M1.2 flare from AR 4420 (N16E26, beta-gamma) peaking at 23/0459UT was also observed. There are currently four numbered and two unnumbered regions on the solar disk, with AR 4420 being the largest and most magnetically complex. This region continued to exhibit some growth across the UT day. Flare-active AR 4419 also displayed some minor growth as it rotates toward the western limb of the Sun. Two new active regions appeared and exhibited growth over the last 24 hours at S05E47 and N14E58, with both appearing to exhibit beta magnetic classifications, although analysis is affected by foreshortening effects. All other regions are either stable or in decay. Solar flare activity over 24-26 Apr is forecast at the R1 level, with a chance of R2, due to ongoing growth and flare activity from AR 4419 and AR 4420, as well as potential activity from regions rotating over the eastern solar limb. Solar proton conditions were at the S0 level throughout 23-Apr. S0 conditions, with a slight chance of S1, are forecast for 24-26 Apr, given the ongoing solar activity over the last 24 hours from active regions in geoeffective positions. Coronal mass ejections (CMEs) were associated with each of the five M-class flares observed on UT day 23-Apr. A north-east directed medium-velocity CME associated with the M1.2 flare from AR 4420 was observed in SOHO/LASCO beginning at 23/0512UT. Modelling of this event indicates a glancing impact, with a forecast arrival at Earth on 26-Apr at 0300 +/-10 hours. The four CMEs associated with flares from AR 4419 were all modelled to miss the Earth. The solar wind continued a declining trend over UT day 23-Apr, declining from about 490 km/s to 420 km/s across the UT day. The interplanetary magnetic field strength (IMF, Bt) peaked at 6 nT, with the north-south component (Bz) ranging between -5 and +4 nT. The solar wind speed is expected to continue to decline over 24-Apr, with an increase expected on 25-Apr due to a small equatorial coronal hole. The solar wind speed will then increase further on 26-Apr due to the anticipated arrival of the CME first observed at 23/0512UT.
Solar Activity levels are explained in the SWS Solar Terrestrial Glossary.
