Space Weather Forecast - Discussion

Issued: 2025 Dec 15 0030 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center and processed by SpaceWeatherLive.com

Solar activity

24 h Summary

Solar activity was at low levels with C-class flare activity observed. The largest flare of the period was a C3.8 flare at 14/0742 UTC from a source beyond the SW limb. Accompanying the flare was a Type-II radio sweep with an estimated velocity of 585 km/s, and a CME off the SW in LASCO C2 imagery, beginning at 14/0800 UTC, that is not expected to be Earth-directed. The second largest flare of the period, a C2.3/SF, originated from Region 4307 (S13W34, Dai/beta). This region was the main contributor for the C-class flares observed during the day. A new region was numbered: 4309 (S09W33, Bxo/beta), resulting in five numbered active regions on the visible solar disk. No Earth-directed CMEs were detected in available imagery.

Forecast

There is a chance for M-class flare (R1-R2/Minor-Moderate) activity over 15-17 Dec.

Energetic Particles

24 h Summary

The greater than 2 MeV electron flux reached moderate levels and the greater than 10 MeV proton flux remained steady at background levels during the period.

Forecast

The greater than 2 MeV electron flux is expected to remain at moderate levels on 15 Dec, with high levels likely on 16-17 Dec. The greater than 10 MeV proton flux is expected to persist at background levels through 17 Dec.

Solar Wind

24 h Summary

Solar wind parameters suggested the continued, but weakening influence from a negative polarity CH HSS. Total magnetic field strength (Bt) remained around 4 nT, and the Bz component was mostly neutral or northward throughout the period. Wind speeds decreased from around 650 km/s at the beginning of the period to sustained 500 km/s levels after 14/1800 UTC. Phi angle was predominately negative throughout the period.

Forecast

Solar wind parameters are expected to reflect diminishing negative polarity CH HSS influences over 14-16 Dec. On Dec 17, the influence of another negative CH HSS is likely to contribute to the disturbance of the solar wind conditions near-Earth.

Geospace

24 h Summary

The geomagnetic activity was at quiet levels during the day, under continued, but weakening, negative polarity CH HSS influences.

Forecast

The geomagnetic field is expected to be mostly quiet to unsettled, with a chance for active conditions, over 15-17 Dec as the influences of two negative CH HSS interplay (diminishing the first and starting the second).