Viewing archive of Monday, 13 October 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Oct 13 1235 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
13 Oct 2025	155	026
14 Oct 2025	165	018
15 Oct 2025	170	008

Solar Active Regions and flaring

Solar flaring activity was moderate over the past 24 hours with 2 M-class flares recorded. The largest flare was an M2.7 flare (SIDC Flare 5733), peaking on October 13 at 09:19 UTC, which was produced by SIDC Sunspot Group 639 (NOAA Active Region 4246). This region was emerging quickly and was responsible for most of the flaring activity, including an M1.9 flare (SIDC Flare 5731), peaking on October 13 at 05:26 UTC. SIDC Sunspot group 621 (NOAA Active region 4248) also grew over the period and produced multiple C-class flares. This region was now also divided with a second numbered region assigned to the flux emergence to the east (SIDC sunspot 668, NOAA Active region 4250). Three small new regions were numbered: SIDC sunspot groups 644, 669 and 670 (NOAA Active regions 4252, 4250, 4251 and 4253, respectively). These regions were simple and mostly quiet. The solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares expected and a chance for X-class flares.

Coronal mass ejections

A dimming was observed on disk near SIDC Sunspot Group 639 related to SIDC Flare 5721 C9.6, with peak time 13:50 UTC. An associated Coronal Mass Ejection (SIDC CME 579) is visible to the north in SOHO/LASCO-C2 data from 14:12 UTC and seen in STEREO-A COR2 data from 14:23 UTC. This event is being analysed but initial analysis suggests this event is expected to impact Earth from late on October 15. Another dimming near SIDC Sunspot Group 639 (NOAA Active Region 4246) was observed around 05:10 UTC associated with the M1.9 flare (SIDC Flare 5731). Any associated CME will be analysed when coronagraph data become available.

Solar wind

The solar wind conditions reflected the ongoing influence of the high-speed stream associated with the large equatorial coronal hole that first began to cross the central meridian on October 08 (SIDC Coronal Hole 116). The solar wind speed remained elevated, gradually decreasing from 800 km/s to 680 km/s. The interplanetary magnetic field ranged between 3 and 9 nT. Bz ranged between -7 nT and 8 nT. The solar wind conditions are expected to remain enhanced over the next 24 hours due to the ongoing high- speed stream influence.

Geomagnetism

Geomagnetic conditions reached minor storm levels globally (Kp 5), due to the ongoing high speed stream influence. Locally active conditions were observed (K Bel 4). Active conditions are expected over the next 24 hours, with further periods of minor storm conditions (Kp 5) possible.

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold over the past 24 hours. It is expected to remain below this threshold level over the next 24 hours. There is a small chance of an increase related to any high-level flaring, particularly from SIDC Sunspot Group 639 (NOAA Active Region 4246).

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was at or just above the 1000 pfu threshold. The greater than 2 MeV electron flux is expected to again exceed the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence was at normal to moderate levels and is expected to be a normal to moderate levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 127, based on 15 stations.

Solar indices for 12 Oct 2025

Wolf number Catania	///
10cm solar flux	143
AK Chambon La Forêt	046
AK Wingst	035
Estimated Ap	036
Estimated international sunspot number	132 - Based on 22 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

<< Go to daily overview page