:Issued: 2026 May 19 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 60519 SIDC SOLAR BULLETIN 19 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 19 May 2026 10CM FLUX: 104 / AP: 011 PREDICTIONS FOR 20 May 2026 10CM FLUX: 101 / AP: 010 PREDICTIONS FOR 21 May 2026 10CM FLUX: 098 / AP: 006 Solar Active Regions and flaring: Solar flaring activity was low over the past 24 hours, with only two C-class flares identified. Both were emitted by SIDC Sunspot Group 825 (NOAA Active Region 4436, Alpha magnetic configuration), with the brightest being SIDC flare 7732 (a C2 that peaked on 19 May at 07:40 UTC). More C-class flaring activity is likely in the next 24 hours. Coronal mass ejections: No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours. Solar wind: The Solar Wind (SW) conditions around Earth were affected by a glancing blow from a Coronal Mass Ejection (SIDC CME 656) that arrived on 19 May at 06:00 UTC as expected. The SW speed increased from 480 to 650 km/s, the interplanetary magnetic field (B) reached a maximum value of 8 nT, and its North-South component (Bz) varied from -7 to 5 nT. The effects from the glancing blow are expected to subside in the next 24 hours, with the exception of the SW speed that is predicted to have a more gradual decrease. Geomagnetism: The geomagnetic conditions of the past 24 hours were affected by the arrival of a glancing blow from SIDC CME 656. The global conditions were increased from quiet to active levels (NOAA Kp 2- to 4-) while locally the effect was milder (K BEL 3, only on 19 May at 06:00-09:00 UTC). In the next 24 hours it is expected that the conditions will remain at a similar level. 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 most of the past 24 hours. It reached a peak value of 5200 pfu on 18 May at 13:10 UTC. It is expected to remain near the alert threshold in the next 24 hours. The electron fluence was at moderate levels in the past 24 hours and it is expected to remain at those levels in the next 24 hours. TODAY'S ESTIMATED ISN : 073, BASED ON 18 STATIONS. SOLAR INDICES FOR 18 May 2026 WOLF NUMBER CATANIA : 097 10CM SOLAR FLUX : 105 AK CHAMBON LA FORET : 014 AK WINGST : 013 ESTIMATED AP : 011 ESTIMATED ISN : 087, BASED ON 27 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 # #--------------------------------------------------------------------#