:Issued: 2025 Dec 01 1637 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1300 from 2025 Nov 24 Solar Active Regions (ARs) and flares --------------- The solar flaring activity of the past week started at low levels but increased to moderate levels on 28 Nov and high on 29 Nov. On the 30 Nov it dropped back to low levels. SIDC Sunspot Group (SG) 709 (NOAA Active Region [AR] 4294) produced two M-class flares on 28 Nov and four on 29 Nov, while NOAA AR 4299 produced one M-class flare on 29 Nov. The brightest flare of the past week was SIDC flares 6228, an M5.9 emitted by SIDC SG 709 on 28 Nov at 22:22 UTC. NOAA AR 4299's single flare was an M2.8 that peaked on 29 Nov at 16:07 UTC. Coronal mass ejections --------------------- No Earth-directed Coronal Mass Ejections (CME) were observed in the past week. Coronal Holes --------------------- SIDC Coronal Hole (CH) 139 (a mid-latitude coronal hole with positive polarity) is a small CH that crossed the central meridian in a single day, on 28 Nov. Proton flux levels --------------------- Over the past week the greater than 10 MeV GOES proton flux has been at background levels. Electron fluxes at GEO --------------------- The greater than 2 MeV electron flux, as measured by GOES-19, exceeded the 1000 pfu alert threshold at noon on 25 Nov. It remain above the alert threshold for the rest of the past week and reached a peak of 23000 pfu on 29 Nov at 16:40 UTC. The 24-hour electron fluence increased from normal to moderate levels at the second half of 25 Nov and increased further to high levels at the second half of 29 Nov. It dropped back to moderate levels at the second half of 30 Nov. Solar wind --------------------- The Solar Wind (SW) conditions were disturbed by a High Speed Stream (HSS) that arrived at the second half of 25 Nov. The SW increased to 830 km/s on 25 Nov and the effect lasted until the first half of 30 Nov (when the SW speed dropped to below 600 km/s). The interplanetary magnetic field (B) varied between 2 and 14 nT and its North-South component (Bz) fluctuated between -15 and 12 nT over the past week. Geomagnetism --------------------- The global geomangetic conditions of the past week reached minor storm levels during four three-hour intervals: NOAA Kp 5- on 25 Nov at 00:00-03:00 UTC, Kp 5 on 25 Nov at 06:00-09:00 UTC, Kp 5- on 27 Nov at 09:00-12:00 UTC, and Kp 5- on 27 Nov at 18:00-21:00 UTC. The rest of the week the global conditions varried mostly between unsettled and active levels with short intervals of quiet conditions. The local geomangetic conditions of the past week reached minor storm levels (K BEL 5) on 24 Nov at 12:00 - 15:00 UTC and on 26 Nov at 15:00 - 18:00 UTC. The rest of the week the local conditions followed a very similar pattern to the global conditions, ie varied mostly between unsettled and active levels with short intervals of quiet conditions. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2025 Nov 24 119 102 116 022 B3.9 0 0 2025 Nov 25 /// 099 116 032 B4.2 0 0 2025 Nov 26 /// 082 120 025 B5.6 0 0 2025 Nov 27 134 090 120 026 B8.1 0 0 2025 Nov 28 108 083 138 021 C2.1 2 0 2025 Nov 29 /// 084 160 020 C2.3 5 0 2025 Nov 30 /// 102 180 017 C2.4 0 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 28 2211 2222 2224 ////// M5.9 ///4294 II/2 28 2352 0002 0007 ////// M1.6 ///4294 29 0414 0420 0422 ////// M1.5 17/4294 29 1302 1316 1325 ////// M1.1 17/4294 29 1536 1607 1632 ////// M2.8 /////// 29 2004 2014 2017 S18E80 M1.4 SF 17/4294 29 2134 2148 2154 S18E72 M1.4 1N 17/4294 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#