:Issued: 2026 May 24 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 60524 SIDC SOLAR BULLETIN 24 May 2026, 1230UT SIDC FORECAST SOLAR FLARES : C-class flares expected, (probability >=50%) GEOMAGNETISM : Quiet (A<20 and K<4) SOLAR PROTONS : Quiet PREDICTIONS FOR 24 May 2026 10CM FLUX: 133 / AP: 005 PREDICTIONS FOR 25 May 2026 10CM FLUX: 136 / AP: 003 PREDICTIONS FOR 26 May 2026 10CM FLUX: 140 / AP: 005 Solar Active Regions and flaring: Solar flaring activity was low but frequent over the past 24 hours, with more than 10 C-class flares identified. SIDC Sunspot Group (SG) 870 (NOAA Active Region [AR] 4441, Beta magnetic configuration) and SIDC SG 873 (NOAA AR 4446, Beta magnetic configuration) produced all the C-class flaring activity. Notable flares are the SIDC flares 7771 (a C5 and the brightest flare that peaked on 23 May at 22:04 UTC) and the double-peaked flares 7769 (a C2 with its highest peak on 23 May at 19:55 UTC) and 7775 (a C3 with its highest peak on 24 May at 02:37 UTC). More C-flass flaring activity is expected in the next 24 hours. Coronal mass ejections: No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours. The two CME seen in LASCO-C2/SOHO images as launched on 23 May at 16:12 and 19:12 UTC are back-sided events. The CME seen in LASCO-C2/SOHO images as launched on 24 May at 09:12 UTC is associated with SIDC SG 870 and was launched close to the west limb. None of the three CME is expected to affect Earth. Solar wind: The Solar Wind (SW) conditions of the past 24 hours feature a slow SW regime. The SW speed gradually dropped from 340 and 290 km/s, the interplanetary magnetic field (B) was between 3 and 6 nT, and its North- South component (Bz) varied from -4 to 4 nT. The SW conditions are expected to remain at the current levels in the next 24 hours. Geomagnetism: The geomagnetic conditions of the past 24 hours were at quiet levels both globally and locally (NOAA Kp 0+ to 1+ and K BEL 1 to 2). In the next 24 hours it is likely that they will continue at quiet levels. Proton flux levels: The greater than 10 MeV proton flux, as measured by the GOES-19 satellite, was at nominal levels over the past 24 hours and is likely to remain so in the next 24 hours. Electron fluxes at GEO: The greater than 2 MeV electron flux as, measured by GOES 19, was above the 1000 pfu alert threshold for past 24 hours. It reached a peak value of 4000 pfu on 23 May at 16:55 UTC. It is expected to remain at the same levels in the next 24 hours. The electron fluence was at moderate levels in the past 24 hours and it is expected to remain at the same levels in the next 24 hours. TODAY'S ESTIMATED ISN : 118, BASED ON 18 STATIONS. SOLAR INDICES FOR 23 May 2026 WOLF NUMBER CATANIA : /// 10CM SOLAR FLUX : 137 AK CHAMBON LA FORET : 005 AK WINGST : 002 ESTIMATED AP : 002 ESTIMATED ISN : 118, BASED ON 21 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 # #--------------------------------------------------------------------#