Summary and Forecast

Solar Summary

(last updated 20 Dec 2024 23:30 UT)

Activity 20 Dec: R1 Flares Max Fadeout Freq. Sectors M2.1 0726UT possible lower Mid East/Indian M2.5 1118UT possible lower European Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Dec: 184/137

Solar Forecast

(last updated 20 Dec 2024 23:30 UT)

21 Dec 22 Dec 23 Dec Activity R0-R1, chance R2 R0-R1, chance R2 R0-R1, chance R2 Fadeouts Possible Possible Possible 10.7cm/SSN 180/133 175/129 175/129 COMMENT: Solar activity on UT day 20-Dec was at the R1 level, due to an M2.1 flare at 20/0726UT and an M2.5 flare at 20/1118UT. There are currently up to nine numbered sunspots on the disk. AR3922 (S19W60, beta-gamma) and AR3928 (S17E53, beta) were responsible for the M-class flares in the UT day. Both of these regions appeared stable over the UT day, however AR3927 (S11E48, beta-gamma) and AR3929 (N17E34, beta) showed minor spot development on 20-Dec. An unnumbered region has developed on the solar disk at around S18W24 with beta magnetic complexity. All other sunspot regions are stable. Solar activity is expected to be at R0-R1 levels, with a chance of isolated R2 flares. S0 solar radiation storm conditions were observed on UT day 20-Dec. S0 solar radiation storm conditions are expected over 21-23 Dec. No geoeffective CMEs have been observed over the UT day. The solar wind speed was mostly elevated and steady over the UT day, ranging between 430 km/s and 550 km/s. The solar wind speed is currently at around 490 km/s. The peak total interplanetary field strength (IMF, Bt) was 10 nT and the north-south IMF component (Bz) was +8 to -9 nT. The solar wind is expected to gradually decline towards background levels over 21-23 Dec.

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