:Issued: 2025 Sep 14 1242 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 50914 SIDC SOLAR BULLETIN 14 Sep 2025, 1241UT SIDC FORECAST SOLAR FLARES : C-class flares expected, (probability >=50%) GEOMAGNETISM : Minor storm expected (A>=30 or K=5) SOLAR PROTONS : Quiet PREDICTIONS FOR 14 Sep 2025 10CM FLUX: 115 / AP: 022 PREDICTIONS FOR 15 Sep 2025 10CM FLUX: 114 / AP: 026 PREDICTIONS FOR 16 Sep 2025 10CM FLUX: 114 / AP: 023 Solar Active Regions and flaring: Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C3.5 flare (SIDC Flare 5490) peaking on September 14 at 09:32 UTC, which was produced by SIDC Sunspot Group 640. A total of 6 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 621 (NOAA Active Region 4216) is the most complex region with its beta magnetic configurations. Solar flaring activity is expected to be at low to moderate levels over the next 24 hours, possibly with few C-class flares and a small chance for M-class flares. Coronal mass ejections: No Earth-directed coronal mass ejections (CME) were detected in the available coronagraph observations during the last 24 hour. Coronal holes: Recurrent negative polarity coronal hole (SIDC Coronal Hole 116), which spans from 10 S to 30 N, has crossed the central meridian on Sep 14. The high speed streams originating from this coronal hole are expected to impact the Earth during Sep 14-17. Solar wind: Earth is presently inside the slow solar wind regime. The solar wind speed ranged from 315 km/s to 380 km/s and the interplanetary magnetic field ranged from 5 nT to 10 nT. The North-South component (Bz) ranged between -5 and 6 nT. Enhanced solar wind parameters are expected in the next 24 hours with the arrival of high speed streams from the SIDC Coronal Hole 116 (negative polarity), which started to cross the central meridian on Sep 10. Geomagnetism: Geomagnetic conditions were at quiet to unsettled conditions (NOAA Kp 0 to 3), both globally and locally during the past 24 hours. We expect unsettled to minor storm conditions (K 3 to 5) in the next 24 hours with the arrival of high speed streams from the SIDC Coronal Hole 116 (negative polarity), which started to cross the central meridian on Sep 10. Proton flux levels: The greater than 10 MeV GOES proton flux was below the threshold level over the past 24 hours and it is expected to remain so for the next 24 hours. Electron fluxes at GEO: Over the past 24 hours, the greater than 2 MeV electron flux, as measured by GOES-18 satellite, exceeded above the 1000 pfu threshold level from 16:30 UTC on Sep 13 to 01:45 UTC on Sep 14. The greater than 2 MeV electron flux, as measured by GOES-19 satellite, increased and mostly remained below the threshold level, except for a fluctuation around the threshold level from 15:30 UTC to 20:30 UTC on Sep 13. In the next 24 hours, the electron flux may exceed the threshold level again. The 24h electron fluence is presently at normal level, and it is expected to remain so in the next 24 hours. TODAY'S ESTIMATED ISN : 070, BASED ON 19 STATIONS. SOLAR INDICES FOR 13 Sep 2025 WOLF NUMBER CATANIA : /// 10CM SOLAR FLUX : 118 AK CHAMBON LA FORET : 011 AK WINGST : 006 ESTIMATED AP : 006 ESTIMATED ISN : 061, BASED ON 19 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 # #--------------------------------------------------------------------#