Summary and Forecast
Solar Summary
(last updated 18 Jan 2026 23:34 UT)
Activity 18 Jan: R3 Flares Max Fadeout Freq. Sectors M1.1 17/2351UT possible lower West Pacific X1.9 1809UT probable all East Pacific/ North American Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Jan: 148/102
Solar Forecast
(last updated 18 Jan 2026 23:34 UT)
19 Jan 20 Jan 21 Jan Activity R2, chance of R3 R2, chance of R3 R2, chance of R3 Fadeouts Probable Probable Probable 10.7cm/SSN 160/114 165/119 170/124 COMMENT: Solar flare activity reached the R3 level on 18-Jan, with an X1.9 flare originating from Active Region (AR) 4341 (S11E21, beta-gamma), peaking at 18/1809UT. This region is the largest of eight numbered active regions on the solar disk, and has remained mostly stable over the past 24 hours. Region 4342 (N18E25, beta-gamma) has shown some trailing spot growth over the same period. AR 4348 (S19W01) appeared during the last UT day, and has a beta magnetic classification. A new region has appeared at S03E53 and appears magnetically simple. All other regions were stable or in decay over the previous 24 hours. Solar flare activity is forecast to be at the R2 level, with a chance of R3 over 19-21 Jan due to the flare activity of AR4341. Solar radiation storm conditions reached the S1 level late on UT day 18-Jan. Proton flux became elevated from background levels after 18/1530UT, coincident with the X1.9 flare. Solar proton flux is currently at 17.6 pfu, with further increases in proton flux likely. Solar radiation storm conditions are forecast to be at the S1 level, with a chance of S2 over the period 19-21 Jan. A Coronal Mass Ejection (CME) has been observed on 18-Jan following the X1.9 flare, first observed by Stereo Cor2 at 18/1823UT, and is likely Earth directed, with an impact at Earth forecast for 20-Jan at 0600UT +/- 10 hours. Further analysis will take place as additional imagery becomes available. The solar wind speed declined across UT day 18-Jan, ranging from 680-720 km/s early in the UT day, decreasing to 480-520 km/s by the end of the period. This elevation is due to ongoing high-speed wind stream effects from a coronal hole. The interplanetary magnetic field strength (IMF, Bt) peaked at 10 nT during 18-Jan, with the north-south component (Bz) ranging between -7 and +7 nT, with an extended southward period between 18/1840-1930UT. The solar wind speed is forecast to remain at elevated levels over UT day 19-Jan as the Earth moves through the coronal hole high-speed wind stream. The solar wind speed is forecast to become elevated on 20-21 Jan due to a CME impact forecast for this period.
Solar Activity levels are explained in the SWS Solar Terrestrial Glossary.
