SIDC Weekly Bulletin
Review of past solar and geomagnetic activity.| Source | SIDC (RWC-Belgium) |
| Frequency | Weekly |
| Format | Plain text |
| Mail header | SIDC Weekly Bulletin |
| SIDC code | bul |
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:Issued: 2026 Jul 06 1624 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1331 from 2026 Jun 29 Solar Active Regions (ARs) and flares --------------- Solar flaring activity was high over the week, with 2 X-class flares and more than 40 M-class flares identified. The strongest flares were an X1.1 flare (SIDC Flare 8067), peaking on June 30 at 20:50 UTC, and an X1.3 flare (SIDC Flare 8130), peaking on July 04 at 20:41 UTC. Both were produced by SIDC Sunspot Group 860 (NOAA Active Region 4479). This region was the dominant source of flaring activity during the week and produced most of the M-class flares, while maintaining a complex beta-gamma-delta magnetic configuration as it crossed the disk and approached the west limb. SIDC Sunspot Group 886 (NOAA Active Region 4478) was also complex and active, producing several M-class flares, including an M8.5 flare on July 01 and an M6.3 flare on July 03. SIDC Sunspot Group 899 (NOAA Active Region 4475) produced an M5.8 flare on June 30 before rotating towards the west limb. SIDC Sunspot Group 901 (NOAA Active Region 4480) also contributed to M-class flaring activity before rotating over the west limb. By the end of the period, SIDC Sunspot Groups 907, 908, 909, and 910 had newly emerged on the visible disk, with SIDC Sunspot Group 910 (NOAA Active Region 4482) rotating onto the east limb. Coronal mass ejections --------------------- Several Coronal Mass Ejections (CMEs) were observed during the week. SIDC CME 679 was a wide halo CME associated with the X1.1 flare (SIDC Flare 8067) from SIDC Sunspot Group 860 (NOAA Active Region 4479) on June 30. It had a plane-of-sky speed of about 750 km/s and an estimated true speed of about 1000 km/s, and produced a solar wind shock near Earth on July 03 at 11:20 UTC. Three successive Earth-directed CMEs, SIDC CME 680, SIDC CME 681, and SIDC CME 682, were observed on July 01 and July 02 from SIDC Sunspot Group 860 (NOAA Active Region 4479). They were associated with the M1.3, M3.5, and M4.2 flares, respectively, and were expected to arrive around July 05 at 12:00 UTC, with an uncertainty of about 12 hours. SIDC CME 683 was associated with the M6.7 flare (SIDC Flare 8104) from SIDC Sunspot Group 860 on July 03 and had an estimated true speed of about 850 km/s. Its arrival is expected around July 07 at 18:00 UTC, with an uncertainty of about 12 hours. A further CME associated with the X1.3 flare (SIDC Flare 8130) on July 04 became visible in GOES/CCOR-1 from around 22:30 UTC, during SOHO/LASCO and STEREO data gaps. Coronal Holes --------------------- SIDC Coronal Hole 159, a recurrent positive polarity coronal hole associated with an extension of the southern polar coronal hole, crossed the central meridian around June 30. Its extension reached southern mid-latitudes, but the probability of a clear high-speed stream arrival at Earth was considered low due to its southern location. Later in the period, SIDC Coronal Hole 170, an equatorial coronal hole with negative magnetic polarity, emerged on the eastern side of the visible solar disk. Proton flux levels --------------------- The greater than 10 MeV proton flux remained below the 10 pfu threshold throughout the week. A slight enhancement was observed near the end of the period following an M-class flare, but no proton event occurred. Electron fluxes at GEO --------------------- The greater than 2 MeV electron flux was at moderate levels at the beginning of the week and was briefly above the 1000 pfu threshold early in the period. It decreased below the threshold around June 30 at 18:00 UTC and remained below the threshold afterwards. The 24-hour electron fluence was at moderate levels at the beginning of the period and then returned to normal levels. By the end of the week, the greater than 2 MeV electron flux was at normal levels and the 24-hour electron fluence remained below the alert threshold. Solar wind --------------------- Solar wind conditions were initially in a slow solar wind regime, with speeds decreasing from about 450 km/s to about 370 km/s and a weak interplanetary magnetic field. Around June 30 at 11:00 UTC, a shock-like enhancement was observed, with the solar wind speed increasing from about 330 km/s to about 430 km/s and the total interplanetary magnetic field increasing from about 4 nT to 12 nT. This disturbance was possibly associated with the arrival of an ICME related to SIDC CME 678. Solar wind conditions then remained slightly disturbed until July 03, when a clear solar wind shock was observed near Earth at 11:20 UTC. This shock was associated with the arrival of the interplanetary structure related to SIDC CME 679. The solar wind speed later increased to 550-640 km/s, the total interplanetary magnetic field reached about 24.5 nT, and Bz turned strongly southward, reaching about -19 nT early on July 04. Solar wind conditions remained disturbed on July 05, with the magnetic field gradually decreasing and Bz rotating northward. Geomagnetism --------------------- Geomagnetic conditions were mostly quiet to unsettled at the beginning of the week. Unsettled to active intervals followed the shock-like solar wind enhancement on June 30. The strongest geomagnetic response occurred on July 04, following the arrival and passage of the interplanetary structure associated with SIDC CME 679. NOAA Kp reached 7 during the 03:00 to 06:00 UTC interval on July 04, corresponding to major storm conditions. Locally, K BEL reached 6 during the 05:00 to 07:00 UTC interval, corresponding to moderate storm conditions. The storm was mainly driven by the prolonged southward Bz interval within the enhanced interplanetary magnetic field. Geomagnetic activity decreased afterwards. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2026 Jun 29 191 125 195 004 C1.6 1 0 2026 Jun 30 216 126 203 025 C1.6 2 1 2026 Jul 01 188 150 201 018 C2.4 11 0 2026 Jul 02 157 127 203 005 C2.5 3 0 2026 Jul 03 145 114 187 012 C2.9 5 0 2026 Jul 04 /// 099 161 062 C4.6 16 1 2026 Jul 05 /// 098 139 022 C2.9 10 0 --------------------------------------------------------------------------- # RC : Sunspot index (Wolf Number) from Catania Observatory (Italy) # EISN : Estimated International Sunspot Number # 10cm : 10.7 cm radioflux (DRAO, Canada) # Ak : Ak Index Wingst (Germany) # BKG : Background GOES X-ray level (NOAA, USA) # M,X : Number of X-ray flares in M and X class, see below (NOAA, USA) --------------------------------------------------------------------------- NOTICEABLE EVENTS SUMMARY DAY BEGIN MAX END LOC XRAY OP 10CM Catania/NOAA RADIO_BURST_TYPES 29 2113 2140 2152 ////// M1.4 62/4479 30 0039 0116 0136 ////// M1.3 58/4475 30 1237 1257 1323 S08W54 M5.8 3 58/4475 30 2034 2050 2100 N14W19 X1.1 2B 62/4479 II/3IV/3 01 0619 0627 0630 N17W21 M1.1 SF 62/4479 01 0637 0643 0647 N19W24 M1.0 1 62/4479 01 0728 0735 0738 N17W21 M1.5 SN 62/4479 01 0807 0817 0820 N17W21 M2.5 SB 62/4479 01 1004 1008 1011 N19W24 M1.3 1 62/4479 VI/1 01 1422 1431 1436 ////// M1.1 62/4479 01 1439 1454 1512 N15W27 M2.6 2N 62/4479 01 1844 1943 1955 N15W32 M3.5 2B 62/4479 01 2015 2022 2028 S10W75 M1.8 SF 58/4475 01 2257 2309 2313 S10W25 M8.5 2B 63/4478 III/3 02 0137 0156 0204 N16W30 M4.2 SF 62/4479 III/2 01 2349 0002 0016 ////// M1.1 63/4478 02 1021 1026 1028 S19W49 M2.8 SN 61/4480 VI/2III/3 02 2303 2312 2316 ////// M1.2 62/4479 03 1303 1313 1316 S16W64 M1.4 1F 64/4480 03 1749 1811 1832 ////// M6.7 62/4479 V/2III/2II/2CTM/2 03 1857 1859 1903 S07W51 M6.3 2B 63/4478 III/2II/2 03 1959 2008 2019 S01W40 M1.5 SF 63/4478 03 2350 0005 ////// M2.0 64/4480 04 0013 0023 0032 N16W71 M2.3 SF 62/4479 04 0059 0113 0121 N16W71 M2.1 SF 62/4479 04 0152 0201 0208 ////// M1.2 /////// 04 0321 0332 0340 N15W76 M3.7 1N 62/4479 VI/2 04 0341 0342 0343 N15W76 M4.0 1 62/4479 04 0504 0515 0522 N14W74 M1.3 S 62/4479 04 0748 0807 0814 ////// M1.8 62/4479 04 0748 0807 0814 N13W84 M1.8 SF 64/4480 04 0841 0852 0856 N14W80 M1.0 SF 62/4479 04 1104 1112 1119 N14W83 M3.2 1N 62/4479 04 1341 1351 1358 N14W83 M3.2 1 62/4479 VI/2 04 1602 1606 1611 N14W82 M1.1 S 62/4479 04 1836 1848 1903 N13W81 M1.9 1N 62/4479 04 1923 1936 1940 ////// M1.5 63/4478 04 2029 2041 2047 ////// X1.3 ///4482 VI/2II/1 04 2216 2224 2229 N13W81 M1.1 1F 62/4479 04 2346 2348 2353 ////// M1.0 62/4479 05 0024 0031 0036 N16W83 M1.3 SF 62/4479 05 0419 0432 0439 N18W78 M1.3 SF 61/4480 05 0441 0447 0452 ////// M1.0 62/4479 05 0521 0539 0549 N18W80 M2.7 S 62/4479 05 1056 1100 1102 ////// M1.4 62/4479 05 1104 1110 1130 N14W84 M1.0 SF 62/4479 05 1641 1645 1648 N13W87 M1.4 SF 62/4479 III/2II/1 05 1751 1757 1802 ////// M5.3 62/4479 05 1856 1907 1911 ////// M1.4 62/4479 III/1 05 2114 2122 2138 ////// M1.0 62/4479 III/1 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#
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This report is sent once a week, typically on a monday.The weekly bulletin gives an overview of solar and geomagnetic activity of the past week and includes a noticeable solar events list.
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