Summary and Forecast

Solar Summary

(last updated 28 Mar 2026 23:31 UT)

Activity 28 Mar: R1 Flares Max Fadeout Freq. Sectors M1.3 0418UT possible lower E. Asia/Aust. Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Mar: 162/116

Solar Forecast

(last updated 28 Mar 2026 23:31 UT)

29 Mar 30 Mar 31 Mar Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 160/114 158/112 155/109 COMMENT: Solar activity on UT day 28-Mar was R1 due to an M1.3 flare from AR4405 (S24E60, beta-gamma). The flare was a slow rise long duration event and had an associated CME. The small intermediate spots within this region have redistributed. Solar region AR4401 (N26W11, beta) was flare quiet and is showing decay in its trailer spots and redistribution in its leader spots. These two medium sized regions are the largest of the on disk regions. Smaller AR4404 (N17E54, beta) produced an isolated C4.1 flare at 28/1135UT. There are currently eight solar regions on the visible solar disk. Most regions are smaller in size. All other sunspot regions are either stable or in decay. Solar activity is expected to be R0-R1 over 29-31 Mar. No Earth directed CMEs have been observed. A southeast directed CME associated with the M1.3 flare was observed from 28/0348UT in LASCO and 28/0442UT in STERE0-A space based coronagraph imagery and was modelled as an Earth miss, passing well behind the Earth. A very narrow faint northeast CME was observed from 28/1212UT and is not considered significant. S0 solar radiation storm conditions were observed on UT day 28-Mar. S0 solar radiation storm conditions are expected over 29-31 Mar. An isolated coronal hole is visible in the northwest solar quadrant and another is visible in the southeast solar quadrant. The solar wind speed on UT day 28-Mar was light to moderate. The solar wind ranged from 344 to 405 km/s and is currently at 359 km/s. The peak total interplanetary field strength (IMF, Bt) was 7 nT and the north-south IMF component range (Bz) was +2 to -7 nT. The IMF Bz component was periodically mildly southward by up to -5nT during the UT day. From 28/2017UT a small increase was observed in the IMF total field to 7nT and the IMF became very steady with the Bz component also steady at -7nT southward for the interval 28/2017-2205UT. Whilst the increase in IMF Bt is small it may indicate an indistinct very weak CME transient, though other solar wind parameters did not show a deflection. The solar wind environment is expected to initially be near background levels early on 29-Mar. Solar wind 27 day recurrence patterns suggest that the coronal hole located in the northwest solar quadrant will moderately increase the solar wind speed from late in the UT day on 29-Mar to 31-Mar. The flux of electrons with an energy of greater than 2 MeV at geosynchronous orbit as measured by the US GOES satellite has been enhanced, which is statistically associated with the increased risk of geosynchronous satellite operational anomalies.

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