Summary and Forecast

Solar Summary

(last updated 09 Dec 2023 23:30 UT)

Activity 09 Dec: R1 Flares Max Fadeout Freq. Sectors M1.5 0955UT possible lower Mid East/Indian M1.0 1319UT possible lower European Observed 10.7 cm flux/Equivalent Sunspot Number for 09 Dec: 128/81

Solar Forecast

(last updated 09 Dec 2023 23:30 UT)

10 Dec 11 Dec 12 Dec Activity R0-R1,chance R2 R0-R1,chance R2 R0-R1,chance R2 Fadeouts Possible Possible Possible 10.7cm/SSN 128/81 125/78 120/72 COMMENT: Solar activity on UT day 09-Dec was at the R1 level due to two M1 flares from AR3511(S23W56, beta-gamma). This region has recently shown initial growth then a decline in its leader spots towards the end of the UT day. Solar region AR3513(N19E15, beta-gamma) has shown growth in its trailer spots with some decline in its intermediate spots. There are currently eight numbered sunspot regions visible on the solar disk. All other sunspot regions are either stable or in decay. Solar activity is expected to be at R0-R1 levels over 10-12 Dec, with the chance of an isolated R2 flare. No significant Earth directed CMEs have been observed. A large north directed CME, out of the ecliptic plane, was observed from 09/0436UT associated with an erupting solar prominence on the north-northwest limb and is not considered to be Earth directed. Two faint CMEs directed to the southwest were observed from 09/0512UT and 09/1012UT. These minor CMEs could not be definitively associated with on disk activity and model runs were conducted assuming AR3511 as the origin. The model runs of these faint minor slow CMEs showed an Earth miss. A slow southeast CME was observed from 09/1212UT associated with a filament eruption centered at S35E65 during the interval 09/0845-1130UT, with the subsequent model run showing an Earth miss. The solar wind speed on UT day 09-Dec decreased, ranging from 467 to 384 km/s and is currently near 370 km/s. The peak total interplanetary field strength (IMF, Bt) was 5 nT and the north south IMF component (Bz) range was +4 to -4 nT. The solar wind speed is expected to decrease over 10-Dec. A narrow coronal hole spans the solar central meridian in the southern solar hemisphere and may cause a mild increase in wind speed from 11-Dec. An isolated coronal hole is visible near the solar equator in the eastern solar hemisphere.

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