:Issued: 2026 Sep 18 1231 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 60918 SIDC SOLAR BULLETIN 18 Sep 2026, 1230UT SIDC FORECAST SOLAR FLARES : Quiet conditions (<50% probability of C-class flares) GEOMAGNETISM : Quiet (A<20 and K<4) SOLAR PROTONS : Quiet PREDICTIONS FOR 18 Sep 2026 10CM FLUX: 097 / AP: 007 PREDICTIONS FOR 19 Sep 2026 10CM FLUX: 095 / AP: 007 PREDICTIONS FOR 20 Sep 2026 10CM FLUX: 093 / AP: 007 Solar Active Regions and flaring: Solar flaring activity was very low over the past 24 hours. The X-ray flux was below C level. Only 1 numbered sunspot group was identified on the disk over the past 24 hours: SIDC Sunspot Group 946 (NOAA Active Region 4528) currently located at S11W83, with an Alpha magnetic configuration and was stable over the past 24 hours. Solar flaring activity is expected to be very low over the next 24 hours, with a small chance for C-class flares. Coronal mass ejections: No Earth directed CMEs were detected in the last 24 hours. Solar wind: The solar wind has been gradually returning to a slow solar wind configuration in the last 24 hours. The solar wind speed is at present close to 410 km/s and the interplanetary magnetic field intensity is around 4 nT. Similar conditions can be expected for the next 24 hours. Geomagnetism: Geomagnetic conditions have been quiet to unsettled both locally and at planetary levels (Kp and K_Bel up to 3). Similar conditions can be expected for the next 24 hours. Proton flux levels: The greater than 10 MeV proton flux on GOES-18 is at background levels. Electron fluxes at GEO: The greater than 2 MeV electron flux, as measured by GOES-18 and GOES-19, remained below the 1000 pfu alert threshold over the past 24 hours and is expected to remain so over the next 24 hours.The 24-hour electron fluence was at normal levels and is expected to remain at normal levels over the next 24 hours. TODAY'S ESTIMATED ISN : 006, BASED ON 17 STATIONS. SOLAR INDICES FOR 17 Sep 2026 WOLF NUMBER CATANIA : 022 10CM SOLAR FLUX : 097 AK CHAMBON LA FORET : 014 AK WINGST : 011 ESTIMATED AP : 010 ESTIMATED ISN : 016, BASED ON 30 STATIONS. NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM Catania/NOAA RADIO_BURST_TYPES NONE END BT #--------------------------------------------------------------------# # Solar Influences Data analysis Center - RWC Belgium # # Royal Observatory of Belgium # # # # Website http://www.sidc.be. # # E-mail sidc-support@oma.be # # To unsubscribe http://www.sidc.be/registration/unsub.php # # # # Legal notices: # # - Intellectual Property Rights: # # http://www.astro.oma.be/common/internet/en/data-policy-en.pdf # # - Liability Disclaimer: # # http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf # # - Use and processing of your personal information: # # http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf # #--------------------------------------------------------------------#