Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
481 FXXX12 KWNP 271231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Sep 27 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 with six C-class flares from Regions 4534 (N10, L=77), which crossed the west limb on 26 Sep, and 4536 (N02W80, Cso/beta-gamma). Region 4535 (N11W19, Bxi/beta) exhibited significant flux emergence during the period but no flaring activity. Region 4533 (S13, L=05) decayed to plage, and new Region 4543 (S08W73, Bxo/beta) was numbered this period. The remaining regions were stable or in decay. No Earth-directed CMEs were detected in available coronagraph imagery. .Forecast... Solar activity is likely to reach low levels with a slight chance for an M-flare (R1-R2/Minor-Moderate) on 27-28 Sep. Solar activity is expected to decrease to very low levels on 29 Sep. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels this period, with a max of 1,260 pfu at 26/1645 UTC. The greater than 10 MeV proton flux was steady at background levels. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 27-29 Sep. The greater than 10 MeV proton flux is expected to remain at background levels through 29 Sep. Solar Wind .24 hr Summary... The solar wind environment remained mildly enhanced as CH HSS influences weakened. Total magnetic field strength decreased throughout the reporting period, ending the period at 3 nT. The Bz (north-south) component varied between +/-5 nT. Solar wind speeds gradually declined from a peak of around 480 km/s to around 415 km/s by the end of the period. The phi angle was largely positive, with more variability before 26/2045 UTC. .Forecast... The solar wind environment is expected to gradually return to background levels on 27 Sep, and persist at background levels through 29 Sep. Geospace .24 hr Summary... The geomagnetic field was at quiet to active levels under diminishing CH HSS influences. .Forecast... The geomagnetic field is expected to be at quiet to unsettled levels for the later half of 27 Sep as CH HSS influences subside. Mostly quiet geomagnetic conditions are expected to prevail on 28-29 Sep.