Summary and Forecast

Solar Summary

(last updated 14 Dec 2025 23:30 UT)

Activity 14 Dec: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 14 Dec: 119/71

Solar Forecast

(last updated 14 Dec 2025 23:30 UT)

15 Dec 16 Dec 17 Dec Activity R0 R0 R0 Fadeouts None expected None expected None expected 10.7cm/SSN 120/72 120/72 120/72 COMMENT: Solar activity was at the R0 level for UT day 14-Dec. There is currently no solar region of significant area on the visible solar disk. Solar region AR4296 located behind the southwest solar limb at solar latitude S16 produced a C3.8 flare at 14/0742UT. Solar region AR4304 (N25W85, beta) and AR4307 (S15W31, beta-gamma) produced low level C class flares. Solar region AR4308 (N17E33, beta) continues to grow though remained flare quiet. The chance of an isolated R1 flare may be slightly increasing if AR4308 and AR4307 continue to develop in coming days. Region AR4304 is rotating off disk. There are currently five regions on the visible solar disk. Other regions are stable or in decay. R0 conditions are forecast for 15-17 Dec. S0 solar radiation storm conditions were observed on 14-Dec. S0 solar radiation storm conditions are expected over 15-17 Dec. The longer transequatorial eastern arm of a north polar extension coronal hole is now at the solar central meridian. No geoeffective coronal mass ejections were observed over the past UT day. A southwest CME, with limited expansion, was observed from 14/0800UT in association with the C3.8 flare from behind the southwest solar limb. This event is not considered to be Earth directed. The solar wind speed decreased over the UT day as the influence from the western arm of the coronal hole currently visible on the solar disk declines. The solar wind speed ranged between 667-490 km/s and is currently at 487 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 5 nT and the north-south IMF component (Bz) range was -3 to 4 nT. The interplanetary magnetic field strength is currently very small in magnitude. The solar wind speed is expected to continue to decline over the next few days before increasing again on 18-Dec due to the wind stream from the transequatorial eastern arm of the coronal hole now at the solar central meridian.

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