FXXX12 KWNP 130031 DAYDIS :Product: Forecast Discussion :Issued: 2025 Dec 13 0030 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # http://www.swpc.noaa.gov/wwire.html # # Forecast Discussion # Product: Forecast Discussion Issued: 2025 Dec 13 0030 UTC Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center .24 hr Summary... Solar activity reached moderate levels with an M2.0 flare at 12/0505 UTC from Region 4296 (S15W83, Eho/beta-gamma), which triggered a sympathetic M1.1 from Region 4294 (S16W93, Dkc/beta-gamma-delta) at 12/0544 UTC. The M-class events were accompanied by Type-II (estimated velocity 410 km/s) and Type-IV radio sweeps, and by a CME that became visible in LASCO C2 at 12/0524 and will not impact Earth, according to its modeled propagation path. Region 4307 (S12W05, Dri/beta-gamma) showed continued flux emergence in its intermediary region, developing new spots along its southern edge. A new region rapidly developed along the eastern limb and was numbered as Region 4308 (N08E59, Bxo/beta). All other regions were stable or in decay. .Forecast... R1-R2 (Minor-Moderate) flare activity levels are likely on 13 Dec due to the potential of Region 4296 and 4294 near the W limb. Probabilities for flare activity decrease through 15 Dec as the major flare producing regions move beyond the west limb. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux remained at moderate levels throughout the period. The greater than 10 MeV proton flux remained at background. .Forecast... The electron flux is expected to become elevated through 14 Dec as a high speed stream (HSS) originating from the negative polarity CH in the Suns northern hemisphere becomes geoeffective. The flux is likely to surpass the 1,000 pfu threshold during the diurnal maxima. As complex regions in the western hemisphere move beyond the limb, the greater than 10 MeV proton flux at geostationary orbit is expected to remain at background levels. Solar Wind .24 hr Summary... Solar wind parameters suggested the onset of a co-rotating interacting region (CIR) associated with a negative polarity CH HSS, with an embedded transient possible, during the period. Total magnetic field strength (Bt) was elevated over the UT day with a peak flux of 15 nT observed at 12/2102 UTC. The Bz component was primarily negative with a rotation to as far south as -15 nT. Wind speeds remained relatively steady between ~400-460 km/s. Phi angle transitioned from predominantly negative to variable after 12/2028 UTC. .Forecast... Solar wind enhancements associated with the negative polarity CH HSS are likely to persist over 13-15 Dec. Geospace .24 hr Summary... The geomagnetic field had an isolated period of G1 (Minor) storming levels late on 12 Dec due interaction with the CIR ahead a negative polarity CH HSS. .Forecast... The geomagnetic field is expected to reach G1 (Minor) geomagnetic storm levels on 13 Dec due to ongoing CH HSS influence. Active conditions on 14 Dec, and unsettled conditions on 15 Dec, are then expected during the waning phase of the CH HSS.