Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
113 FXXX12 KWNP 131231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Sep 13 1230 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 low levels due to an impulsive C5.8/Sf observed at 12/1720 UTC from Region 4521 (N09, L=265) as it transited the western limb. This region, along with Region 4430 (N19W56, Cao/beta), both added a few B-level enhancements during the period. Five of the six numbered regions were either stable or reflected slight decay. Region 4525 (N11W45, Cao/beta) initially exhibited decay, but redeveloped a few leader spots later in the period. At approximately 12/1830 UTC, upper coronal field line movement with subsequent wide-expanse reconnection was observed in SUVI 195A imagery throughout most of the southern hemisphere. Subsequently, a large, slow moving CME was first observed in GOES CCOR2 imagery at approximately 12/1930 UTC, moving SSW. Initial hypothesis is a large upper coronal CME not visible in SUVI lower coronal field of view lifted off. Analysis and modeling indicated a trajectory far south of the ecliptic, with no impacts expected at Earth. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at very low levels, with C-class flares likely and a slight chance of isolated low-level M-class flares (R1-Minor) through 15 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a maximum flux of 1,830 pfu observed at 12/1710 UTC. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to decline to low to moderate levels on 13-14 Sep and increase to high levels on 15 Sep. The greater than 10 MeV proton flux is expected to remain at background levels. Solar Wind .24 hr Summary... Solar wind parameters remained near-background levels. Total field strength varied between 3-8 nT, the Bz component fluctuated between +4 to -6 nT, and solar wind speed ranged between 320 - 424 km/s through the period. The phi angle was in a mostly positive orientation with a few extended oscillations into a negative position. .Forecast... Negative CH HSS effects are anticipated to begin late on 13 Sep and last through 15 Sep. Geospace .24 hr Summary... The geomagnetic field was at quiet to isolated unsettled levels. .Forecast... The geomagnetic field is expected to be quiet to unsettled, with an isolated active period possible on 13 Sep as +CH HSS influence is expected to continue. Late on 13 Sep, an anticipated SSBC ahead of a negative polarity coronal hole high speed stream is anticipated to begin influencing the IMF, bringing unsettled to active levels, with a chance for an isolated period of G1 (Minor) storming on 14-15 Sep.