Routine Space Environment Product (Daily)
Issued by NWS
Issued by NWS
539 FXXX12 KWNP 110031 DAYDIS :Product: Forecast Discussion :Issued: 2026 Sep 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 was low due to weak C-class flare activity observed from Region 4524 (N12W27, Hsx/alpha), the largest a C1.6/Sf at 10/1712 UTC. B-class flare activity was observed from Region 4521 (N09W67, Hsx/alpha) and 4525 (N11W10, Cri/beta). Both Regions 4525 and 4530 (N19W21, Dri/beta) exhibited some intermediate spot growth. The remaining regions were either stable or in decay. Other activity included a faint CME observed off the western limb at about 09/1900 UTC in STEREO A and CCOR imagery from a potential filament liftoff near center disk. Another filament liftoff was observed near S15W30 at about 10/0315 UTC with a more obvious CME off the western limb. Both CMEs were modelled as slow-moving with potential weak Earth impact late on the 14th into the 15th. .Forecast... Solar activity is anticipated to remain low, with a slight chance of low-level M-class flares (R1-Minor) 11-13 Sep. There is little evidence in NSO GONG helioseismology of any looming active regions of note just beyond the east limb. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a maximum flux of 3,077 pfu observed at 10/1745 UTC. The greater than 10 MeV proton flux was at background values. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels 11-12 Sep and decline to low to moderate on 13 Sep. The greater than 10 MeV proton flux is expected to remain at background levels. Solar Wind .24 hr Summary... Solar wind conditions were at mostly background levels. Total IMF strength peaked at 6 nT, while the Bz component varied between +3 to -4 nT. Solar wind speed changes were minimal, varying between 417-486 km/s The phi angle was mostly in a negative orientation from 10/0000-10/1015 UTC, and predominantly positive through the end of the period. .Forecast... Solar wind conditions are anticipated to experience some minor disturbances due mainly to a small, positive polarity CH HSS anticipated to be geoeffective through 12 Sep. Negative CH HSS effects are anticipated to begin on 13 Sep. Geospace .24 hr Summary... The geomagnetic field was at quiet to unsettled levels. .Forecast... The geomagnetic field is expected to be quiet to unsettled through 13 Sep with active periods possible on 11 Sep due to CH HSS onset.