Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
227 FXXX12 KWNP 110031 DAYDIS :Product: Forecast Discussion :Issued: 2025 Dec 11 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 # Solar Activity .24 hr Summary... Solar activity reached moderate level due to multiple low level (R1-Minor) M-class flares, which all originated from Region 4294 (S15W69, Ekc/beta-gamma-delta). Persistent flux emergence in its leading spot has supported its flare activity over the last two days. Other regions with notable growth were Regions 4304 (N25W36, Cai/beta-gamma) and 4305 (S25E20, Dai/beta-gamma). All other regions were either stable or in decay. Region 4294 was responsible for the largest flare of the period, an M4.4/2B at 10/2208, that was also associated with a 520 sfu Tenflare, a Type-II radio burst (estimated velocity of 849 km/s) and an eruption observed at the SUVI 284A channel. Further coronagraph data is necessary to analyze this eruption. There were no Earth directed CMEs in the available coronagraph imagery. .Forecast... R1-R2 (Minor-Moderate) flare activity is expected (75% chance), with a slight chance (15%) for R3 (Strong) activity. Probabilities remain elevated due to the complexity and history of the large complex of three regions in the southwest part of the disk. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit reached high levels, with a maximum of 2183 pfu at 10/1735 UTC. The greater than 10 MeV proton flux remained at background. .Forecast... Without the geoeffective positioning of any coronal hole high speed stream until 13 Dec, electrons will continue to trend towards moderate levels through 12 Dec. Due the growth of Region 4294 and its favorable positioning in the west, there remains a slight chance (15%) for an S1 (Minor) radiation storming event on 12 Dec with decreasing chances as it moves beyond the limb. Solar Wind .24 hr Summary... Solar wind parameters have been enhanced throughout much of the period. A weak transient moved through starting around 10/0325 UTC. Total interplanetary magnetic field (Bt) rose to 13 nT with the north-south (Bz) component dropping to a minimum of -7 nT. Wind speeds increased slightly from 350 km/s towards 425 km/s for a brief period. The heliospheric current sheet, as determined by the phi angle, moved from negative (towards the Sun) to positive. Bt remained around 7 nT, wind speeds around 380 km/s until approximately 10/1800 UTC. Between 1800-2100 UTC conditions deteriorate. Bt originally at 11 nT at 10/1824 UTC began dropping and reached a minimum of 2 nT at 10/1957 UTC. Rotation began to occur within the heliospheric sheet with a rise in density. A solar wind signature indicative of a reverse shock. Bt increased up to 17 nT at 10/2013 UTC with the Bz component dropping to -16 nT - both have been holding steady at this magnitude since. .Forecast... Solar wind parameters will remain enhanced going into 11 Dec with nominal conditions being regained once current conditions pass. The co-rotating interacting region (CIR) ahead of the negative polarity coronal hole (CH) high speed stream (HSS) expected to arrive 12 Dec. Geospace .24 hr Summary... The geomagnetic field reached G2 (Moderate) geomagnetic storming levels due to the solar wind disturbance that arrived around 10/2000 UTC. .Forecast... G1-G2 (Minor to Moderate) geomagnetic storming levels are expected to continue into 11 Dec with a return to unsettled to active conditions thereafter.