Summary and Forecast

Solar Summary

(last updated 17 Jan 2026 23:30 UT)

Activity 17 Jan: R1 Flares Max Fadeout Freq. Sectors M2.1 1029UT possible lower European Observed 10.7 cm flux/Equivalent Sunspot Number for 17 Jan: 159/113

Solar Forecast

(last updated 17 Jan 2026 23:30 UT)

18 Jan 19 Jan 20 Jan Activity R1, chance of R2 R1, chance of R2 R1, chance of R2 Fadeouts Possible Possible Possible 10.7cm/SSN 160/114 160/114 165/119 COMMENT: Solar flare activity reached the R1 level on UT day 17-Jan, with an M2.1 flare peaking at 17/1029UT from Active Region (AR) 4341 (S11E32, beta-gamma-delta). This region is the largest and most magnetically complex of seven regions on the visible disk, and has remained mostly stable over the last 24 hours. It has also produced numerous C-class flares during this period. Active regions 4342 (N18E39, beta-gamma) and 4343 (S10W18, beta-gamma) have also produced several low-level C-class flares over the past UT day and have remained stable. AR 4344 (N20E28, beta) has shown some growth over the last UT day, while all other regions have remained stable or in decay. Solar flare activity is forecast to remain at the R1 level, with a chance of R2 activity, based on the flare activity of active regions 4341, 4342, and 4343. S0 solar radiation storm conditions were observed over the past 24 hours, with the proton flux at background levels. S0 conditions are expected to persist over the period 18-20 Jan. No Earth-directed coronal mass ejections were observed in the past 24 hours in the available coronagraph imagery. The solar wind speed was elevated across 17-Jan, ranging between 680-750 km/s for most of the UT day. A discrete jump was observed at 17/0215UT, likely coinciding with a connection to a coronal hole high-speed wind stream. A decrease in the interplanetary magnetic field strength (IMF, Bt) was also observed at this time, dropping from a peak value of 12 nT down to 8 nT. The north-south component (Bz) of the magnetic field ranged between -9 and +10 nT, but has ranged between -6 and +7 nT since the high-speed wind stream connection. Connection to the coronal hole high-speed wind stream was also observed in ACE EPAM data, with an ion enhancement occurring at 17/0535UT. The solar wind stream is forecast to remain at very strong levels over 18-20 Jan due to these coronal hole high-speed wind stream effects.

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