:Issued: 2024 May 18 1233 UTC :Product: documentation at http://www.sidc.be/products/meu #--------------------------------------------------------------------# # DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC # # (RWC Belgium) # #--------------------------------------------------------------------# SIDC URSIGRAM 40518 SIDC SOLAR BULLETIN 18 May 2024, 1231UT SIDC FORECAST SOLAR FLARES : M-class flares expected (probability >=50%) GEOMAGNETISM : Active conditions expected (A>=20 or K=4) SOLAR PROTONS : Quiet PREDICTIONS FOR 18 May 2024 10CM FLUX: 215 / AP: 013 PREDICTIONS FOR 19 May 2024 10CM FLUX: 210 / AP: 009 PREDICTIONS FOR 20 May 2024 10CM FLUX: 208 / AP: 006 Solar Active Regions and flaring: Solar flaring activity was high during the last 24 hours, with an M7 flare emitted from NOAA Active Region (AR) 3685 (magnetic configuration Beta-Gamma, Catania sunspot group 9) yesterday at 21:08 UTC. The second brightest X-ray flare of the past 24 hours was a C7 from NOAA AR 3679 (magnetic configuration Beta-Gamma, Catania sunspot group 6). NOAA AR 3671 (magnetic configuration Beta, Catania sunspot group 93) and NOAA AR 3686 (magnetic configuration Alpha, Catania sunspot group 11) produced the remaining of the C-class flaring activity. For the next 24 hours, the pair of NOAA AR 3685 and 3686 is expected to continue producing M-class flares with a chance of an X-class flare. Coronal mass ejections: No Earth directed Coronal Mass Ejections (CME) have been observed in the available coronagraph data. A partial halo CME seen in SOHO/LASCO-C2 images as launched yesterday at 12:48 UT is judged to be a back-sided event. Solar wind: The Solar Wind (SW) conditions were disturbed by a Coronal Mass Ejection (CME)-induced shock yesterday at 12:40 UTC. The CME itself followed a few minutes later. This is most likely the CME expected to arrive as glancing blow yesterday evening. The SW speed peaked to 520 km/s because of the arrival of the disturbance. The total interplanetary magnetic field (Bt) increased to 17 nT but has decline significantly now. The North-South magnetic component (Bz) fluctuated between -15 and 13 nT during the CME disturbance. The interplanetary magnetic field phi angle turned to the direction of the Sun as a result of the CME arrival and stayed predominantly to this direction. The effects of the CME are expected to diminish in the next 24 hours. Geomagnetism: The global geomagnetic conditions reached storm levels yesterday (NOAA Kp: 5 15:00-18:00 UTC, 6 18:00-21:00 UTC, 5+ 21:00-24:00 UTC) and now fluctuate between quiet and unsettled levels. Locally the conditions also increased to the minor storm level (K BEL 5) yesterday at 18:00-21:00 UTC and now fluctuate between quiet and unsettled levels. For the next 24 hours the geomagnetic conditions are expected to vary between active and quiet levels both globally and locally. Proton flux levels: The greater than 10 MeV proton flux, as measured by the GOES-18 satellite, continued its drop during the past 24 hours and is now in low levels. It is likely that it will remain at low levels in the next 24 hours, however, there is a small chance of a new proton event and an increase in flux above the 10 pfu alert level. Electron fluxes at GEO: The greater than 2 MeV electron flux, as measured by the GOES-18 satellite, increased during the past 24 hours and reached the 1000 pfu alert threshold momentarily. This was most likely a localised event as it lasted for a very short time and was not observed by GOES-16. Hence, the electron flux is expected to remain at low levels in the next 24 hours. The 24h electron fluence increased but remained at normal levels during the past 24 hours. It is expected to decrease further in the next 24 hours. TODAY'S ESTIMATED ISN : 167, BASED ON 12 STATIONS. SOLAR INDICES FOR 17 May 2024 WOLF NUMBER CATANIA : 193 10CM SOLAR FLUX : 204 AK CHAMBON LA FORET : 037 AK WINGST : 031 ESTIMATED AP : 028 ESTIMATED ISN : 181, BASED ON 22 STATIONS. NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM Catania/NOAA RADIO_BURST_TYPES 17 2033 2108 2126 S12E62 M7.2 2B 09/3685 II/2IV/2 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 # #--------------------------------------------------------------------#