:Issued: 2026 Apr 29 1247 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 60429 SIDC SOLAR BULLETIN 29 Apr 2026, 1246UT SIDC FORECAST SOLAR FLARES : M-class flares expected (probability >=50%) GEOMAGNETISM : Minor storm expected (A>=30 or K=5) SOLAR PROTONS : Quiet PREDICTIONS FOR 29 Apr 2026 10CM FLUX: 140 / AP: 017 PREDICTIONS FOR 30 Apr 2026 10CM FLUX: 135 / AP: 022 PREDICTIONS FOR 01 May 2026 10CM FLUX: 135 / AP: 025 Solar Active Regions and flaring: Solar flaring activity was moderate over the past 24 hours, with 3 M-class flares identified. The largest flare was a M1.5 flare (SIDC Flare 7545) peaking on April 28 at 13:53 UTC, which was produced by SIDC Sunspot Group 847 (NOAA Active Region 4420). A total of 9 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 847 (NOAA AR 4420) is the most complex region, with a beta-gamma-delta magnetic configuration, which has produced all the M-class flaring activities over the past 24 hours. Solar flaring activity is expected to be low to moderate over the next 24 hours, with few C-class flares, possibly M-class flares and a low chance for X-class flares. Coronal mass ejections: No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph observations during the last 24 hour. Coronal holes: SIDC Coronal Hole (CH) 142, spanning 25 N - 80 N (recurrent negative polarity), has started to cross the central meridian on Apr 29, and the high-speed streams from this CH may enhance the solar wind environment near Earth during May 02-06. Solar wind: Earth is presently within the slow solar wind regime, speed ranging from 310 km/s to 380 km/s. The North-South component (Bz) ranged between -4 and 4 nT. The interplanetary magnetic field ranged between 1 nT to 5 nT. Slow solar wind conditions are expected to continue over the next 24 hours unless the high speed streams from the SIDC Coronal Hole 149, which crossed the central meridian during Apr 26-28 (recurrent negative polarity), arrives at Earth. Geomagnetism: Geomagnetic conditions were globally and locally quiet (NOAA Kp 0 to 1 and K BEL 1 to 2). In the next 24 hours, active to minor storm conditions (K 4 to 5) are possible if the high speed streams from the SIDC Coronal Hole 149, which crossed the central meridian during Apr 26-28 (recurrent negative polarity), arrives at Earth. 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: The greater than 2 MeV electron flux, as measured by GOES-19 and GOES-18 satellites, remained below the threshold level over the past 24 hours and is expected to remain so in the coming 24 hours. The 24h electron fluence is presently at normal level and is expected to be at normal to moderate levels in the next 24 hours. TODAY'S ESTIMATED ISN : 134, BASED ON 18 STATIONS. SOLAR INDICES FOR 28 Apr 2026 WOLF NUMBER CATANIA : 160 10CM SOLAR FLUX : /// AK CHAMBON LA FORET : 006 AK WINGST : 002 ESTIMATED AP : 003 ESTIMATED ISN : 141, BASED ON 27 STATIONS. NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM Catania/NOAA RADIO_BURST_TYPES 28 1217 1223 1229 N15W38 M1.0 S 85/4420 III/1 28 1349 1353 1355 N17W38 M1.5 SN 85/4420 28 1403 1407 1409 N17W39 M1.1 S 85/4420 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 # #--------------------------------------------------------------------#