Summary and Forecast

Solar Summary

(last updated 03 Dec 2025 23:30 UT)

Activity 03 Dec: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 03 Dec: 200/152

Solar Forecast

(last updated 03 Dec 2025 23:30 UT)

04 Dec 05 Dec 06 Dec Activity R1,chance R2 R1,chance R2 R1,chance R2 Fadeouts Possible Possible Possible 10.7cm/SSN 205/156 210/161 210/161 COMMENT: Solar activity was at the R0 level over the UT day 03-Dec. Large solar region AR4294 (S15E24, beta-gamma-delta) is currently in decay with penumbra spreading and breaking up and a decline in umbral area within the large trailer spot. The intermediate spots of this region initially showed some development then started to decay. Nearby region AR4296 (S14E39, beta-delta) exhibited minor growth in its intermediate spots, though its main leader spot may be in initial decay. Solar region AR4298 (S17E09, beta), which is mostly a simple large monopole spot showed some minor growth in opposite polarity surrounding small spots to the north of the main spot. These three regions are in a sequence in the southeast solar quadrant. Solar region AR4299 (N23E45, beta) located in the northeast solar quadrant is in slight decay, with a reduction in umbral area of its trailer spots. In the southwest solar quadrant smaller solar region AR4297 (S11W38, beta) is rapidly growing. Solar regions AR4297 and AR4299 produced low to middle level C class flares. Currently, there are ten numbered sunspot regions on the visible solar disk. All other sunspot regions on the disk are either stable or in decay. On the northwest solar limb near AR4288 (N19W86, beta) plasma arch movement and plasma ejecta was observed from 03/1251UT in GOES imagery. A section of solar filament near AR4288 also appeared to lift off during this activity. Solar activity is expected to be at the R1,chance R2 level over 04-06 Dec. Solar radiation storm conditions were at the S0 level during UT day 03-Dec, and S0, chance S1 conditions are forecast over the period 04-06 Dec. There were no significantly Earth directed coronal mass ejections observed over the past UT day. A narrow eastward non-Earth directed CME was observed from 03/0105UT. Two faint CMEs directed to the southwest were observed from 03/0105UT and 03/0828UT. The first CME was too faint to model. The second event may be associated with filament activity in the southwest solar quadrant centred at S20W50 visible in GOES 304 imagery. The second CME was found to have a very slow speed (<200km/s) and is not considered significant. A west CME was observed from 03/1106UT which could not be correlated to disk activity, so at this stage is assumed to be far side, and may have subsequently overlapped with a northwest CME associated with the north western limb plasma activity. These CMEs are expected to pass ahead of the Earth. The solar wind speed on UT day 03-Dec increased toward the end of the UT day as the Earth's entered the coronal hole wind stream from the equatorial coronal hole now located in the western solar hemisphere. The solar wind speed ranged from 496 to 368 km/s, and is currently at 495 km/s. The peak total interplanetary field strength (IMF, Bt) was 18 nT and the north-south IMF component range (Bz) was +13 to -13nT. The IMF Bz component gradually drifted increasingly southward from 03/0700UT and the total interplanetary field gradually increased. Two periods of southward IMF conditions were observed 03/1630-1830UT and from 03/2000-2130UT. The solar wind speed is expected to remain elevated over 04-05 Dec.

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